Adverb distribution in Broca’s aphasia;
A different view on the Tree Pruning Hypothesis
Femke Nouwens (0510343)
Master thesis, Utrecht University
November 2007
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Adverb distribution in Broca’s aphasia;
A different view on the Tree Pruning Hypothesis
Master thesis
Femke Nouwens (0510343)
‘Taal en Spraak; verwerking en stoornissen’
Utrecht University
Supervisors: Prof. dr. F.N.K. Wijnen and dr. Ø. Nilsen
Date: December 18, 2007
ii
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Acknowledgements
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After a long period of data analysis and writing this thesis, my ordeal has finally come to an end. I believe
the quotes above reflect the process of realising this thesis quite well. I wanted to investigate adverb
distribution in aphasia, because this subject has not yet been studied extensively. Although I wanted to
avoid diving into the world of hardcore syntax I could not avoid it. I just had to drag that cat by its tale! The
process of determining how to ‘study adverb distribution in aphasia’ was not self-evident either. The world
of adverbs proved to be as varied as the types of adverbs that exist. Despite my fear of hardcore syntax it
was an interesting challenge to understand the relevant phenomena. Gradually my fear of syntax even
vanished and became replaced by enthusiasm because I finally understood what these strange syntactic
trees signified. This enthusiasm could not have evolved if I had not been guided by my two supervisors.
Therefore, I would like to thank Øystein for introducing me to the world of adverbs. Thank you for all your
quick replies to my questions and requests. In addition, I could not have composed such a solid theoretical
framework without your help. I owe my gratitude to Frank for sharing his experience in doing research.
Each time I got stuck you provided your objective and expert opinion and helped me on my way again. I
want to thank Evy Visch-Brink for introducing the topic adverbs in aphasic speech to me. Thank you also
for providing me with speech samples from your study. I thank Rob Zwitserlood for helping me out with my
English.
I want to thank my parents also for granting me the chance to complete this study in linguistics after my
study speech and language therapy. Although you did not exactly know what I was doing (which is logical)
you kept on supporting me and letting me know you were proud of me. Thanks big sister for putting things
into perspective and very welcome distractions. And last, but certainly not least, I want to express my
gratitude to Maarten. You were there to share the ups and downs with me. You kept me motivated and
supported me when things did not work out as I planned. Thank you for being there; I hope you will stay
for a long time.
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iii
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Summary
The goal of this study is to test the plausibility of the Tree Pruning Hypothesis (TPH; Friedmann and
Grodzinsky, 1997) for Broca’s aphasia by examining adverb distribution in spontaneous speech. The TPH
claims that in Broca’s aphasia higher nodes of the syntactic tree are unavailable during sentence
production, whereas lower functional heads are available; the syntactic tree is pruned.
The plausibility of the TPH was analyzed using the universal adverb hierarchy by Cinque (1999). Cinque
claims that adverbs specify distinct functional heads. In this approach adverbs are located at specific fixed
positions in the syntactic tree. Cinque’s claim combined with the TPH leads to the prediction that adverb
distribution should reveal the pruning phenomenon during spontaneous speech of Broca’s aphasic
subjects.
This prediction was tested by analyzing spontaneous speech samples of ten Broca’s aphasics. Ten
unimpaired controls and ten Wernicke’s aphasics acted as control groups. The universal adverb hierarchy
is divided in six hierarchical groups for the analysis. In addition, a more semantic classification of adverbs
in six groups was used which does not follow Cinque’s hierarchy.
Broca’s aphasics preferred low adverb groups most. This was not observed in unimpaired controls. This
distinct preference for low adverb groups is predicted by the TPH. The preference pattern for the
remaining higher adverb groups in Broca’s aphasics was almost equal to unimpaired controls.
Preservation of this preference pattern for higher adverb groups is not compatible with the TPH, since
higher syntactic nodes are assumed to be inaccessible.
The results suggest the existence of a metaphoric ‘on/off switch’ for tree pruning. When the ‘switch’ is on,
high syntactic nodes are inaccessible. When the ‘switch’ is off, high syntactic nodes are available. If the
‘switch’ is turned off a preference pattern in Broca’s aphasics is observed which resembles preferences of
unimpaired controls. However when the ‘switch’ is turned on only low adverbs can be produced.
It is proposed that this ‘on/off switch’ is explained by Avrutin’s Weak Syntax theory (2006). Avrutin claims
that in unimpaired controls narrow syntax processes are the most economical solution for information
encoding. Information however might be encoded by discourse, provided a special register is present.
Avrutin states that in Broca’s aphasia narrow syntax is weakened because of brain damage and loses its
status of most economical system. Consequently, narrow syntax and discourse compete with each other,
which results in a 50/50 chance for either system to win. Situations in which narrow syntax wins the
competition are compatible with situations in which the ‘tree pruning switch’ is off. When discourse wins,
the ‘tree pruning switch’ is turned on.
The alternative non-syntactic division of adverbs did not reveal a semantic deficit. In fact the alternative
division further supports the proposal of an ‘on/off switch’ for tree pruning.
The expected differences between Broca’s and Wernicke’s aphasics regarding syntactic processes could
not be verified in the hierarchical grouping of adverbs. In fact, Broca’s and Wernicke’s aphasics’ adverb
distribution bear considerable similarities. A syntactic deficit appears to be present in Wernicke’s aphasia
also. Close analyses of the alternative division however showed that production patterns in Wernicke’s
and Broca’s aphasics differ. Regarding the highest and lowest adverb groups Wernicke’s aphasics seem
to perform more equal to unimpaired controls than to Broca’s aphasics. Consequently, it is ruled out that
Broca’s and Wernicke’s aphasics have a similar underlying deficit. A deficit of both syntactic and lexical
processes is proposed for Wernicke’s aphasia.
iv
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Table of contents
1.
2.
Acknowledgements
iii
Summary
iv
Introduction
1
Background
3
3
3
8
9
10
13
14
15
16
18
19
2.1. Aphasiology
2.1.1.
2.1.2.
2.1.3.
2.1.4.
Broca’s aphasia
Wernicke’s aphasia
Comparison
Previous theories on adverbs in aphasia
2.2. Adverbs
2.2.1. Cinque’s universal adverb hierarchy
2.2.1.1. Levels of functional heads
2.2.1.2. The adverb hierarchy
2.2.2. An alternative classification of Cinque’s adverbs
2.3. Outline
3.
Methodology
3.1. Participants
3.2. Data
4.
Results
4.1. Results of Cinque’s hierarchical grouping
4.1.1.
4.1.2.
Group comparisons by means of analysis of variance
Correlation analysis
4.2. Results of an alternative grouping of Cinque’s adverb hierarchy
4.2.1.
4.2.2.
Group comparisons by means of analysis of variance
Correlation analysis
4.3. Results of regression analyses
5.
Discussion
5.1.
5.2.
5.3.
5.4.
6.
Page
Grouping according to Cinque’s hierarchy
Grouping according to an alternative approach
Regression analyses
Summary of the results in relation to the research questions and predictions
General discussion and conclusion
6.1.
6.2.
6.3.
6.4.
Discussion and recommendations for further research
Conclusion from the results
Proposal for a refined theory of the deficit in Broca’s aphasia
Requirements for the refined theory
21
21
22
24
26
28
30
32
34
36
37
39
39
42
44
45
47
47
48
48
49
References
50
Appendices
53
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Chapter 1
Introduction
With this thesis I intend to bridge theories of aphasiology and linguistic theories in order to provide further
support for a specific explanation of Broca’s aphasia.
In aphasiology linguistic theories compete with psycholinguistic theories in explaining impairments in
Broca’s aphasia. A prominent linguistic theory is the Tree Pruning Hypothesis by Friedmann and
Grodzinsky (1997). Friedmann and Grodzinsky claim that the syntactic tree in Broca’s aphasia is pruned
from a certain node or functional head upwards. Consequently, nodes of the syntactic tree above the
pruning location are inaccessible during sentence production. Therefore, Broca’s aphasics can merely use
syntactic nodes below the pruning location. Friedmann and Grodzinsky claim that tense (usually omitted)
is located above the pruning location and agreement (intact) is located below the pruning location. Thus,
the functional head of tense is inaccessible to Broca’s aphasics. The functional head for agreement is not
pruned from the syntactic tree and therefore can be used.
Based on empirical research in different languages Cinque (1999) proposed his version of the syntactic
tree wherein a large quantity of distinct functional heads all possibly have a specifier. Cinque claims that
adverbs are specifiers of functional heads. Cinque locates thirty adverb types at distinct locations in the
syntactic tree. According to Cinque, these adverbs are located within the syntactic tree in a clear
hierarchical relation.
Cinque’s adverb hierarchy was used in the present study to investigate whether the tree pruning
phenomenon can be observed in spontaneous speech of Broca’s aphasics. When Cinque’s adverb
hierarchy is combined with tree pruning, adverbs specifying functional heads above the pruning location
are not expected to be produced by Broca’s aphasics. Adverbs that correspond to non-pruned functional
heads will be produced by Broca’s aphasics.
For analyses the adverb hierarchy was divided into groups according to the syntactic hierarchy. In addition
an alternative semantic division was analysed.
Spontaneous speech samples of Broca’s aphasics were analysed in this study because spontaneous
speech reveals which linguistic processes are operational in aphasia. Since few studies have been
1
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
published on adverb distribution in unimpaired language, an unimpaired control group was added. A group
of Wernicke’s aphasics was included because their language production is assumed to differ considerably
from Broca’s aphasics.
First several theories on aphasia and adverb distribution will be presented. Next the outline of the present
study is described, followed by the results and discussion. Finally, a refined theory of tree pruning is
proposed.
2
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Chapter 2
Background
2.1. Aphasiology
Aphasia is a general term for various problems in all language modalities1 after brain damage. Two well
known and quite different aphasia syndromes are fluent Wernicke’s aphasia and non-fluent Broca’s
aphasia. Although the focus of this thesis will be on Broca’s aphasia, spontaneous speech of Wernicke’s
aphasics is analysed also. Wernicke’s aphasics act as a control group together with a group of nonlanguage impaired subjects.
2.1.1.
Broca’s aphasia
Broca’s aphasia is also known as non-fluent, motor or expressive aphasia. In the Wernicke-Geschwind
model (in: Kandel et al., 2000) two brain area’s are responsible for language processing; Wernicke’s area
for comprehension and Broca’s area for production. For a long time, researchers believed that Broca’s
aphasia is caused by unilateral damage in Broca’s area2 in the left hemisphere (Friederici and Kotz, 2003).
Currently, theories about Broca’s aphasia are not restricted to damage in Broca’s area solely. The
suprasylvian area, operculum and insula are associated with this type of aphasia as well. Usually,
additional damage to the white matter is observed. Dharmaperwira-Prins and Maas (1998) report that
damage, restricted to Broca’s area, only causes a transitory language disorder.
A great number of (functional) brain imaging studies have been conducted to shed some light on the
localization of language in the brain. Activation in Broca’s area has been extensively examined.
Conclusive evidence localizing language production is sparse. Sentence production has not been
examined often in these studies. Haller et al. (2005) measured brain activity during sentence production in
1
2
Language modalities: comprehension of spoken language, speaking, reading and writing (Kandel, 2000).
Broca’s area is located in Brodmann’s area 44 and 45 (BA 44 and 45) in the left inferior frontal gyrus (Friedmann and Kotz, 2003).
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
unimpaired controls. They compared word and sentence reading conditions to a sentence production
condition in a functional MRI study. Haller et al. discovered that brain activation during reading aloud of
words and sentences differs significantly from activation during sentence production. In line with previous
results, a significant increase in activation in the left hemisphere in BA 44 and 45 was observed when
sentences were produced, whereas this effect failed to occur in reading conditions. Additional activation
was observed outside Broca’s area and in its right hemisphere homologue. Consequently, Haller et al.
concluded that an entire cortical network is responsible for syntactic processing.
Broca’s aphasics are known for their non-fluent speech. Their speech is characterized as laborious and
slow. Broca’s aphasia is usually related to agrammatism. Ouhalla (1990, in: Lonzi and Luzzatti, 1993)
claimed there is a total loss of functional categories in agrammatism. The term a-grammatic refers to an
inability to use grammar.
However, Lonzi and Luzzatti (1993) proved that Broca’s aphasics are not completely unable to use
grammar. Lonzi and Luzzatti state that intact word order resembles intact functional categories. They
examined the ordering of constituents in agrammatic subjects and observed no errors in word order of
finite verbs and adverbs. Therefore, they concluded that functional categories are not completely
inaccessible to agrammatic aphasics.
Currently, the term agrammatism refers to a subset of Broca’s aphasics incapable of using grammar.
Patients in this subset only produce one and two-word utterances mainly existing of content words.
Dharmaperwira-Prins and Maas (1998) refer to Broca’s aphasia as a morpho-syntactic disorder, which
implies a deficit in syntax and morphology. Words and constituents are incorrectly ordered and
morphemes for plurals and verb-inflection are omitted. Therefore, speech is often described as
‘telegraphic’.
Agrammatic aphasics’ speech mainly consists of uninflected content words, such as verbs and nouns and
lacks function words. Severe agrammatic aphasics are unable to express syntactic dependencies and
produce word strings without syntactic structure, as in the following example from a Broca’s aphasic
participant in this study. He talks about going out for a cup of coffee:
(1)
Speech therapist: Een kop koffie met gebak?
(a cup of coffee with pastry?)
Subject: Nee (een uh nee) enkel tabak.
(no (a uhm no) merely tobacco)
Nee en zonder iets d’r in.
(no and without something there in)
Speech therapist: Was het op een terras?
(was it at a terrace?)
Subject: (…) een (uh ja) terras nee.
(a (uhm yes) terrace not).
Problems in Broca’s aphasia are not restricted to language production. Comprehension is impaired as
well, although usually less severely. Dharmaperwira-Prins and Maas (1998) and Kandel (2000) both claim
that the underlying deficit in Broca’s aphasia could be a deficit in production and comprehension of
relations through language. Especially utterances requiring a precise interpretation of syntactic structure in
order to understand meaning will usually cause confusion. Compare for instance:
(2)
[The girl with the long braids]1 kicked [the little boy]2.
(3)
[The little boy]2 t1 was kicked by [the girl with the long braids]1 t2.
(adapted from: Gazzaniga et al, 2001).
The meaning of (2) can be derived by combining individual meanings of the separate words in their
consecutive order. To understand the passive sentence (3), correct analysis of syntactic dependencies is
necessary.
Traditional linguistic theories relate Broca’s aphasia to syntactic processing. Grodzinsky (in: Zurif et al.,
4
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
1993; and Grodzinsky, 2000) posed the Trace Deletion Hypothesis and claims that Broca’s aphasics are
unable to represent traces of moved constituents. This causes problems with assigning thematic roles,
which is crucial for correct interpretation of utterances. Bever (1970, in: Zurif et al., 1993) proposed that
Broca’s aphasics use a non-grammatical strategy to assign thematic roles; “assign the agent role to the
first NP”. In example (3), two traces are present; t1 and t2. These traces represent the basic word order
from which the surface order is derived; example (2). If these traces are not represented in Broca’s
aphasia and Bever’s strategy is applied, the sentence will be interpreted incorrectly as ‘the boy kicks the
girl’ instead of: ‘the girl kicks the boy’.
Bastiaanse et al. (2003) claim a general movement deficit for Broca’s aphasia, which means that moved
constituents cause problems during comprehension and production. In their experiment Bastiaanse et al.
observed that agrammatic subjects did not have many problems with inflection of the finite verb. However,
movement of the verb to the second position was problematic. Consequently, the Dutch verb-second rule
causes problems for these patients, because the verb must move from its sentence final base position,
found in subordinate clauses, to the second position in the sentence, for instance:
(4)
Hij weet dat [zijn broer de vaas brak].
(5)
Zijn broer brak de vaas.
Dutch basic word order: S-O-V
(He knows that [his brother the vase broke])
Surface “active” word order: S-V-O
(His brother broke the vase)
In many reports on language behaviour of Broca’s aphasics a distinction is made between production of
tense and agreement. Friedmann and Grodzinsky (1997) explain this from a syntactic approach. They
adopt the sentence structure by Pollock (1989, in: Friedmann and Grodzinsky, 1997), who splits inflection
into a higher node for tense and a lower node for agreement. Tense and agreement do not belong to the
same functional category in Pollock’s structure. This split inflection structure is presented in Figure 1.
Figure 1: Tree pruning in Pollock’s Split Inflection structure (from: Friedmann and Grodzinsky, 1997).
Friedmann and Grodzinsky (1997) and Friedmann (2001) present data that suggest a clear distinction in
damage between operations nested in nodes above NegP and operations that appear in the tree below
5
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
the NegP-node. From this evidence they conclude that the syntactic tree is pruned from NegP upwards
meaning that higher nodes are inaccessible, whereas lower nodes are accessible. The Complementizer
Phrase (CP) and Tense Phrase (TP), which are situated above NegP, are inaccessible to the Broca’s
aphasic. Operations located above the pruning location will not be realized in Broca’s aphasics’ overt
speech. Nodes below NegP however are preserved and will be available to Broca’s aphasics.
Friedmann and Grodzinsky (1997) observed three groups of agrammatic subjects with different levels of
severity; tense impaired + agreement impaired, tense impaired + agreement intact and tense intact +
agreement intact + CP impaired. They suggest that pruning might occur at different levels:
Pruning above VP
tense impaired + agreement impaired
Pruning above AgrP
tense impaired + agreement intact
Pruning above TP
tense intact + agreement intact + CP impaired
Friedmann and Grodzinsky (1997) discuss the severity metric, which corresponds to the syntactic location
of the node where tree pruning occurs: the lower, the greater the number of impaired functional
categories. This means that the lower tree pruning occurs, the more severe the aphasia.
Friedmann (2001) provides more evidence for the TPH. Friedmann conducted several experimental
studies and discovered that operations in CP, such as wh-questions and embedding, are often impaired in
agrammatism. The TPH can explain a range of errors observed in agrammatism.
Based on the TPH, Friedmann (2001) predicts problems with verb movement and inflection in verb second
(V2) in Dutch. In V2 the finite verb raises from its sentence final base position in VP, via Inflectional
Phrase (IP: tense and agreement) to second position; CP. If the TPH is correct the verb can no longer
move to neither TP nor CP. This will lead to verbs appearing only in the low VP domain and would cause
verbs to remain uninflected. Bastiaanse and van Zonneveld (1998; in Friedmann, 2001) support this
prediction.
In addition to linguistic (syntactic) theories, many alternative psycho-linguistic studies have been
performed concerning the underlying deficit in Broca’s aphasia. Linebarger (1983, in: Gazzaniga et al.,
2001) discovered that performance on grammatical judgement tasks is considerably better than on
sentence comprehension tasks. This suggests that representation of grammatical knowledge is intact, but
impairment lies in the implementation of grammatical knowledge.
Kolk (1995) proposes that a timing problem is the result of a slow down of syntactic processes in Broca’s
aphasia. As a consequence, sentence processing is disturbed and timing of syntactic processes, such as
applying correct morphology, is disrupted. Subsequently, lexical activation is slowed down and elements
are not available at the requested time in order to be integrated correctly. Kolk states that Broca’s
aphasics frequently omit elements to adapt to their timing problem. If something is not available yet, it can
not be used at that time. Avrutin (2004 and 2006) proposes a similar viewpoint formulated as the ‘Weak
Syntax’ hypothesis.
Avrutin (2004 and 2006) tries to explain the observed optionality in Broca’s aphasic’ speech. Optionality
can be rephrased as: ‘sometimes they are capable of producing grammatical language and sometimes
they are not’. Avrutin distinguishes two language production systems: narrow syntax and discourse.
Avrutin describes narrow syntax as a computational system that operates in isolation. It combines lexical
elements in a manner allowed by the grammar of a specific language. This combination of elements is
regulated by grammatical rules. It is possible for (6) to be formulated by narrow syntax, because no
syntactic rules are violated; word order is correct, inflection is applied, etc:
(6)
Allegedly the jealous wind walked scholastically into the woollen bar when it was raining umbrellas.
Output of the narrow syntax system is regulated by what Chomsky (1995; in: Avrutin 2006) calls the
Conceptual-intentional Interface (C-I). This system prevents us from saying things like (6). Avrutin regards
the C-I as similar to the linguistic discourse or information structure. The information structure is a
computational system as well and is responsible for producing interpretable chunks of information. In
addition to narrow syntax, the C-I system also uses discourse operations to encode language. Usually,
narrow syntax is the most economical and dominant system for speech production and comprehension.
However, in exceptional cases it is possible to encode language using discourse solely. This can occur
when a special register is present, illustrated by the following examples:
6
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
(7)
Maria vertelde een mop aan Peter. Hij lachen.
(8)
Wie heeft jou gisteren opgebeld? Oh, Ø meisje van school.
Femke Nouwens
(Maria told a joke to Peter. He to-laugh.)
(Who has you yesterday called? Oh, Ø girl from school.)
(from: Avrutin: 2006)
It is completely acceptable in Dutch to both omit inflection of the verb in (7) and the determiner in (8).
These special registers require specific contextual conditions, which in the examples are provided by the
previously spoken sentence in (7) and posed question in (8). Production thus depends on discourse in
these special registers.
Avrutin believes that special registers (or context) are capable of replacing functional categories. Example
(7) shows a tenseless, though completely comprehensible sentence. The functional category tense is filed
by the sentence that ‘Mary told a joke to Peter’.
It is possible to omit elements that are normally supplied by narrow syntax, provided that information is
conveyed trough discourse. Tense-information can be provided by operations of the discourse system, for
instance by using a temporal adverb. Agreement affixes however can not be replaced by other elements
from any other register.
Avrutin wonders why unimpaired controls do not depend more on discourse operations. He hypothesizes
that in an economy hierarchy (Reuland, 2001; in: Avrutin, 2006) of linguistic operations (syntax,
semantics, discourse), narrow syntax is the most economical system, whereas discourse is least
economical. In order to meet the requirement of fluent speech, information that is available first, will be
used first. Consequently, unimpaired controls usually encode information by means of narrow syntax.
If we assume that Broca’s area is involved in syntactic processing, damage to Broca’s area may affect
syntactic processing, according to Avrutin. He hypothesizes that narrow syntax loses its status of most
economical system due to damage to Broca’s area; the narrow syntax system is weakened.
Consequently, narrow syntax becomes equally or less economical than discourse. This equality in
economy creates a competition between these systems with equal chances for both systems to ‘win’ this
competition. This competition reflects what is observed in Broca’s aphasics’ speech; sometimes
sentences are completely grammatical and sometimes they are ungrammatical. However, sentences that
we mark as ungrammatical are not entirely ungrammatical. Elements of narrow syntax may be omitted,
but the information of the omitted element becomes available via operations of the discourse system.
When the discourse system can not be used, narrow syntax has to be used. Even though Broca’s
aphasics’ narrow syntax system may function well, the system is slowed down when compared to
unimpaired speakers. This is confirmed by several studies using priming tasks (Swinney et al., 1989 and
Prather et al., 1992; both in: Zurif et al., 1993 and Swinney and Zurif, 1995, for a more detailed discussion
see section §2.1.3).
Avrutin’s account differs considerably from Friedmann and Grodzinsky’s Tree Pruning Hypothesis,
because Avrutin does not state that the syntactic system, i.e. syntactic knowledge, is damaged in Broca’s
aphasia. He claims that implementation of the syntactic knowledge is weakened, possibly due to limited
processing capacities as a consequence of brain damage. Friedmann and Grodzinsky claim that the
syntactic system is damaged, which causes the syntactic tree to be pruned.
This distinction is important, if one wants to make predictions based on these theories. In hypothesizing
that a system is damaged, damaged parts should be damaged always. For the Tree Pruning hypothesis
this would mean that no CP or TP-related operations should be observed in Broca’s aphasia.
Phonology is often impaired in Broca’s aphasia. Phonemic paraphasias3 and verbal apraxia can be
observed during speech. Phonological problems are more pronounced in function words and unstressed
words. This does not imply that phonological errors do not occur in content words. In example (1) above
the subject says “tabak” (tobacco) instead of “gebak” (pastry). This probably is a phonemic paraphasia,
because both phonological forms are very similar.
Broca’s aphasics are well aware of their speech errors, which can lead to frustration. Because of
production problems, Broca’s aphasics often use interjections, like “uh” or “well” or standard sentences,
like “Let me think” or “don’t know”.
3
Phonemic paraphasia: a word wherein one or more phonemes have been changed to form another word, for instance “log” instead
of “dog” or “screwscriver” instead of “screwdriver” (Dharmaperwira-Prins and Maas, 1998).
7
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 2 gives an impression of speech of a Broca’s aphasic in narrating the ‘cookie theft’ picture of the
Boston Diagnostic Aphasia Exam (Goodglass and Kaplan, 1972; in: Obler and Gjerlow, 1999).
Kid…kk…can…candy…cookie…candy...well I don’t know but it’s writ...easy does it
Slam...early...fall...men...many...no...girl.
Dishes...soap...soap...water...water...falling...pah...that’s all...dish...that’s all.
Cookies...can...candy...cookies cookies...he...down...That’s all.
Girl...slipping...water...water...and it hurts...much to do.
Her...clean up.
Dishes...up there.
I think that’s doing it.
(examiner: What is she doing with the dishes?)
Discharge...no...I forgot...dirtying clothes?...dish?...water?
(examiner: What about it?)
slippery water...scolded...slipped.
Figure 2: An impression of Broca’s aphasic’s speech (from: Obler and Gjerlow, 1999).
2.1.2.
Wernicke’s aphasia
Wernicke’s aphasia is known as fluent, sensory, receptive or acoustic aphasia (Dharmaperwira-Prins and
Maas, 1998). This type of aphasia is usually related to damage in Wernicke’s area4, in the posterior part of
the superior temporal gyrus in the left hemisphere. A lesion located in the front of Wernicke’s area is
responsible for written language to be better preserved than spoken language. If the lesion is located
towards the rear of this area, i.e. when the auditory cortex is spared, spoken language will be less affected
than written language.
In the traditional Wernicke-Geschwind model Wernicke’s area is responsible for auditory comprehension.
Nowadays Wernicke’s area is viewed to be functioning in the processing of speech sounds which
connects incoming sounds to their corresponding concept, i.e. to their meaning.
Fluent speech with semantic5 and phonemic paraphasias and neologisms6 is typical for this aphasia
syndrome. Butterworth (1979, in: Obler and Gjerlow, 1999) claimed that phonemic paraphasias are
caused by a ‘random phoneme generator’ which becomes active when a target word can not be found.
This could explain the fact that paraphasias in Wernicke’s aphasia often show no similarities anymore with
the target word, resulting in neologisms. In comparison to Broca’s aphasics, Wernicke’s aphasics produce
significantly more paraphasias.
Wernicke’s aphasics have difficulties selecting words that represent their intention correctly. Speech
consists of an abundance of function words and wrongly used grammatical forms, leading to
paragrammatisms7. Because of paragrammatisms, a subgroup of Wernicke’s aphasics mainly produces
long ungrammatical sentences. Goodglass and Kaplan (1972) consider syntax of these aphasics to be
paragrammatic instead of agrammatic, because of the high quantity of -although incorrectly used- complex
verb tenses, embedded subordinate clauses, function words, etc.
Wernicke’s aphasics display elaborate descriptions or circumlocutions, because they can not reach the
core of the intention they want to express. Wernicke’s aphasics’ speech is difficult to understand, because
of its abnormal syntactic relations and lack of content. Speech of severely impaired patients which
consists of merely paraphasias is called jargon (semantic or phonemic). Aphasics who speak in jargon are
completely incomprehensible.
Obler and Gjerlow (1999) refer to Wernicke’s aphasia as a lexical-semantic disorder, implying problems
with lexical activation and semantics, i.e. with meaning of an utterance. Gazzaniga et al. (2001) argue that
4
Wernicke’s area is located in Brodmann’s area 22 and 42 (Kandel, 2000) in the left peri-sylvian regions (left superior temporal
sulcus and gyrus) (Grodzinsky and Friederici, 2006).
5
Semantic paraphasia: a word that is replaced by another word that was not intended, for instance “cat” instead of “dog” or
“cardriver” instead of “screwdriver” (Dharmaperwira-Prins and Maas, 1998).
6
Neologism: a word that can no longer be recognized because of the phonemic or semantic changes (Dharmaperwira-Prins and
Maas, 1998).
7
Paragrammatism: incorrect use of morpho-syntactic rules, which causes (long) ungrammatical sentences (Dharmaperwira-Prins
and Maas, 1998).
8
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
there is no complete loss of semantic knowledge. Experiments showed that Wernicke’s aphasics benefit
from lexical priming8. Lexical priming aids these patients in a lexical decision task. It does not guarantee
comprehension, because subjects in the experiments remained impaired at word meaning tasks.
Auditory comprehension is poor, which makes these patients unaware of their own errors. This contributes
to the severe communication problems of these patients. Obler and Gjerlow (1999) even mention that
comprehension is more severely impaired than production. Wernicke (in: Goodglass and Kaplan, 1972)
states that poor auditory comprehension might be the cause of paraphasias, since speech output is not
monitored well enough by the auditory feedback system.
The deficit underlying Wernicke’s aphasia has been studied, but not as frequently as in Broca’s aphasia.
Tyler (1988, in: Obler and Gjerlow, 1999) found that these aphasics are capable of building syntactic
structures in order to facilitate comprehension. She examined word recognition in normal sentences,
semantically anomalous sentences and non related word strings. Wernicke’s aphasics benefited of a
word-position effect, which is a syntactic effect, in the normal and semantically anomalous sentences, but
not in word strings. Building the syntactic tree improves word recognition by anticipating on which word
type can be expected based on sentence structure. Although the meaning of sentences produced by
Wernicke’s aphasics is abnormal, sentence structure appears to be close to normal. Conservation of the
ability to build syntactic trees probably contributes to well preserved sentence intonation and prosody.
By examining semantic combinatorial operations in patients with damage to Wernicke’s area Piñango et
al. (1997; in: Zurif, 2000) found that these operations are slowed down, whereas damage to Broca’s area
caused a slow down in syntactic composition processes. Consequently, the frequently mentioned but little
proven semantic deficit might be true for Wernicke’s aphasia.
In Figure 3 a fragment is presented of speech from a Wernicke’s aphasic. The patient was asked to
answer the following question: “What brought you to the hospital?”.
Is this some of the work that we work as we did before?
All right.
From when wine (=why) I’m here.
What’s wrong with me because I...was myself until the taenz took something about the time between
me and my regular time in that time and they took the time in that time here and that’s when the the
time took around here and saw me around in it it’s started with me no time and then I bekan (=began)
work of nothing else that’s the way the doctor find me that way.
Figure 3: An impression of Wernicke’s aphasic’s speech (from: Obler and Gjerlow, 1999).
2.1.3.
Comparison
At first sight the major difference is the effort that has to be made in order to communicate. Broca’s
aphasics struggle visibly with the production of an utterance and often produce an incorrect response.
Wernicke’s aphasics on the other hand produce long sentences fluently.
The comprehensibility of their message forms another striking difference between Broca’s aphasics and
Wernicke’s aphasics. Broca’s aphasics often speak in content words (verbs, nouns, adjectives), whereas
Wernicke’s aphasics overuse function words (Dharmaperwira-Prins and Maas, 1998). Broca’s aphasics
produce elliptical messages, but they produce only few semantic errors. They convey information using
words with much intrinsic meaning (i.e. content words) without having to use syntax. Wernicke’s aphasics
produce word strings with no obvious relation, which results in incomprehensible sentences with many
semantic errors, but only few syntactic errors.
This difference in production between semantics and syntax between these two aphasia syndromes is
also present in comprehension. Zurif et al. (1993) compared Broca’s aphasics’ to Wernicke’s aphasics’
comprehension in a lexical priming study. Previous lexical priming studies reported that Wernicke’s
aphasics, just like unimpaired controls, benefit from a lexical cue in word recognition, because Wernicke’s
aphasics immediately activate an antecedent when they come across a trace. Broca’s aphasics do not
seem to benefit from semantic context in word recognition. However, Swinney et al. (1989, in: Zurif et al.,
1993), Prather et al. (1992, in: Zurif et al., 1993) and Swinney and Zurif (1995) did observe lexical priming
8
Lexical priming: “processing a lexical item is faster for target words when these items are immediately preceded by semantically
associated words than by unrelated words” (adapted from Swinney and Zurif, 1995).
9
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
effects in Broca’s aphasia, but they are delayed. Consequently, the lexical cue is not available at the time
it is required and no beneficiary effect occurs. This reveals that slow down of syntax in Broca’s aphasia
might also be present in lexical activation what was already claimed by Kolk (1995).
Zurif et al. (1993) showed, using a lexical priming study, that Wernicke’s aphasics reactivate antecedents
when they come across the corresponding trace. This reactivation must be based on two properties of
utterances; the syntactic and the thematic grid. Shapiro and Levine (1990, in: Zurif et al., 1993) showed
that Wernicke’s aphasics are insensitive to the argument properties of verbs. Therefore, the thematic grid
is not completely present. Reactivation of antecedents that Wernicke’s aphasics showed in Zurif et al.’s
study is therefore based on the syntactic grid alone. This means that Wernicke’s aphasics are capable of
building the syntactic tree which aids their comprehension. This strategy however does not guarantee
flawless comprehension. Swinney and Zurif (1995) classify these errors as results of imprecision in the
semantic network. They mention also that Wernicke’s aphasics are capable of performing syntactic
operations, such as establishing coreference, even if they do not understand the sentence.
The previously mentioned lexical priming effects for Broca’s and Wernicke’s aphasics have been
replicated by Prather et al. (1997). In addition to the delayed priming effect in Broca’s aphasia, Prather et
al. found a prolonged priming effect in Wernicke’s aphasia. Prolongation of this effect might cause
semantic confusion during comprehension of successive (parts of) sentences. This might explain
comprehension deficits in Wernicke’s aphasia.
Piñango and Zurif (2001) claim to truly separate9 syntax from semantics in their investigation. They
examined the semantic operations aspectual coercion10 and complement coercion11 in Broca’s and
Wernicke’s aphasia. If semantics is impaired, which is hypothesized for Wernicke’s aphasics, coercion
must raise problems. This turned out to be true. Broca’s aphasics performed equally on the coercion and
non-coercion condition. They did not have difficulties with the interpretation of the additional aspects that
coercion demands. Wernicke’s aphasics had problems in the coercion condition. A sentence like ‘The girl
jumped until dawn’ was interpreted by Wernicke’s aphasics as a girl taking one giant leap that lasted until
dawn, whereas normal judgement would be a girl repeatedly jumping until dawn. Since this operation is
independent of syntactic operations, according to Piñango and Zurif, they conclude that Wernicke’s
aphasics have a semantic problem. They even claim that Wernicke’s area (left posterior cortical region) is
responsible for semantic composition and Broca’s area (left anterior cortical region) for syntactic
composition.
2.1.4.
Previous theories on adverbs in aphasia
So far, research on adverb distribution in aphasia has been limited. Most studies report on adverb
distribution in agrammatic aphasia.
Lonzi and Luzzatti (1993) were among the first experimenters who studied adverb distribution in aphasia.
They questioned the reality of the “Total loss of functional categories” that was brought forward by Ouhalla
(1990, in: Lonzi and Luzzatti, 1993). Advocates of this theory claim that all functional categories are lost in
Broca’s aphasia. They claim that the functional category of Inflection, IP or Infl, serves to regulate correct
word order of a sentence. Ouhalla states that an erroneous word order indicates a breakdown of the
functional category Infl. i.e. inflection.
Lonzi and Luzzatti examined finite verb-adverb word orders in agrammatic language and hypothesized
that correct word order implies intact functional categories. They discovered correct finite verb-adverb(s)
word orders in agrammatic subjects in their study and concluded that functional categories (especially IP;
9
It is not clear whether it is possible to separate syntax from other linguistic operations. In fact the claim that coercion is a truly
syntactic operation is still under debate.
10
Aspectual coercion = “an operation whereby a repetition function is introduced, either as a generative operation in the semantic
component or as a type shifting in the lexicon, to achieve aspectual compatibility between the verbal head and its temporal modifier”
(from Piñango and Zurif, 2001). Example: ‘The girl jumped until dawn’ is usually interpreted as a repeating event of jumping. The
interpretation of repetition comes from the verb ‘jumping’, because it has an intrinsic beginning and end. If one hears /jump/, one
usually assumes that it is a rapid action. Thus, if it happens until dawn; one will assume that the jumping is repeated until dawn.
11
Complement coercion = “a semantic operation triggered by a semantic incompatibility between an event-taking verb and a nonevent object. In this circumstance, an extra piece of content is pasted in, thereby solving the selectional incompatibility. We use the
term ‘enriched semantic composition’ to refer to the set of semantic compositional operations that has this sort of pasting in property”
(from Jackendoff, 1997; in: Piñango and Zurif, 2001). Example: ‘He began the book’ misses the activity verb ‘reading’ or ‘writing’, but
because of the restricted activities one performs with books, this sentence is usually interpreted as: ‘He began reading / writing the
book’ (Piñango and Zurif, 2001).
10
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
inflection) are not disrupted in agrammatism. Agrammatic subjects had access to the rule system that
generates adverb distribution. Assuming that aphasic subjects will not use a new strategy after brain
damage (such as a default strategy: verb before adverb), these findings show that aphasic subjects
perform like unimpaired controls regarding word order production.
Lonzi and Luzzatti did not mention whether verb inflection errors occurred and whether adverb-infinitive
word orders were produced correctly. This could have provided more information about the degree of
breakdown of the language system, supposing that breakdown is apparent in the first place.
Bastiaanse et al. (2003) present a study on object scrambling in Dutch Broca’s aphasics. Object
scrambling is a phenomenon where the basic word order of adverb-object-finite verb is changed by
moving the object over the adverb. Consequently, the following scrambled word order is obtained: objectadverb-finite verb. This operation involves movement of constituents. Bastiaanse et al. claim that
movement is impaired in Broca’s aphasia. They claim that not only movement to higher nodes of the
syntactic tree is impaired but movement in general. This is in contradiction with the Tree Pruning
Hypothesis. Bastiaanse et al. chose object scrambling because this operation takes place in lower nodes
of the syntactic tree, which are not impaired according to the TPH.
Bastiaanse et al. tested their claim using two sentence completion tasks. In the first task, subjects were
presented with a picture of two persons performing a different action, for example a man cutting a tomato
and one man cutting bread. The following sentences had to be completed:
(9)
Unscrambled:
target = adverb-object-finite verb
Dit is de man die vandaag de tomaat snijdt en dit is de man die...
(This is the man who today the tomato cuts and this is the man who…)
Correct answer: vandaag het brood snijdt.
(today the bread cuts)
(10)
Scrambled:
target = object-adverb-finite verb
Dit is de man die de tomaat vandaag snijdt en dit is de man die...
(This is the man who the tomato today cuts and this is the man who…)
Correct answer: het brood vandaag snijdt.
(the bread today cuts)
(from: Bastiaanse et al, 2003)
In the first task the adverb (vandaag) was constant, whereas the object was altered. Results of this
experiment show that aphasic subjects frequently omitted the adverb. The unimpaired control group
performed without any errors. To rule out a gapping strategy12 in which known information (in this case:
the adverb) is omitted, a second experiment was conducted. In this experiment known information was no
longer the adverb, but the object:
(11)
Unscrambled: target = adverb-object-finite verb
Dit is de man die vrijwillig het boek leest en dit is de man die...
(This is the man who voluntarily the book reads and this is the man who...)
Correct answer: verplicht het boek leest.
(obligatory the book reads)
12
Example of this gapping strategy: instead of: “Dit is de man die vandaag de tomaat snijdt en dit is de man die vandaag het brood
snijdt” the response with applying this gapping strategy would be: “Dit is de man die vandaag de tomaat snijdt en dit is de man die ∅
het brood snijdt”.
11
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
(12)
Femke Nouwens
Scrambled: target = object-adverb-finite verb
Dit is de man die het boek vrijwillig leest en dit is de man die...
(This is the man who the book voluntarily reads and this is the man who…)
Correct answer: het boek verplicht leest.
(the book obligatory reads)
(adapted from: Bastiaanse et al, 2003)
If a gapping strategy would have been used, Bastiaanse et al. expected subjects to omit known
information, which is the object in the second experiment. However, this did not happen. Aphasic subjects
persisted in omitting the adverb. Therefore, adverb omission must have been caused by a different
impairment; a movement deficit, according to Bastiaanse et al. However, difficulties are expected with the
object and not with the adverb, because the object is moved over the adverb in object-scrambling.
Unfortunately Bastiaanse et al. do not discuss this.
Moreover, these results might be attributed to different causes. These sentences are highly artificial for
instance. Furthermore, the instruction might not be understood completely by aphasic subjects. From the
article it does not become clear whether subjects had a practice round and whether they were clearly
instructed to complete the sentence exactly equal to the example. Consequently, the value of this study is
questionable.
Alexiadou and Stavrakaki (2006) present a case study of a Greek-English bilingual with a remarkable
adverb distribution. Alexiadou and Stavrakaki, like Cinque (see section §2.2.1), consider adverbs to
appear in specifier position of functional categories; speaker orientated adverbs specify CP, modal
adverbs specify MoodP, aspectual adverbs specify AspP and negative adverbs specify NegP. The
location of adverbs reveals which functional categories are intact in agrammatism. Alexiadou and
Stavrakaki examined this by means of a constituent ordering task with obligatory adverbs corresponding
to functional heads of various heights in the syntactic hierarchy. Results were practically in line with
predictions made by the Tree Pruning Hypothesis; the higher the adverb is licensed in the syntactic tree,
the higher percentage of incorrect responses.
In order to prove whether a central13 deficit is present in agrammatism, Alexiadou and Stavrakaki
investigated comprehension as well. For that purpose a grammaticality judgement task was administered
using various types of adverbs. A similar error pattern showed up in this task, although the overall number
of errors was lower. These findings suggest a central impairment.
Alexiadou and Stavrakaki found differences between English and Greek adverb distribution that can not
be explained by the TPH or movement deficit hypothesis formulated by Bastiaanse. They explain this by
differences in breakdown between languages predicted by Paradis (1988, in: Alexiadou and Stavrakaki,
2006).
Alexiadou and Stavrakaki claim that the error pattern they discovered is in line with the Tree Pruning
Hypothesis. They did not use a control group to explore what happens in unimpaired production. An error
hierarchy might be observed in unimpaired controls as well. In the present study an unimpaired control
group is included to monitor use of adverbs in unimpaired spontaneous speech.
Although studies presented above provide information about adverb distribution in (mainly agrammatic)
aphasia, still very little is known about adverb production in aphasia. Adverb distribution in spontaneous
language has never been described in the literature. It is important not only to concentrate on results
obtained from experiments, because experiments are somewhat artificial. Studying how aphasics use
adverbs when they are not restricted to an experimental condition will be interesting as well. In
spontaneous speech adaptations14 to underlying deficits can become visible. The goal of this thesis is to
contribute to research on adverb distribution in aphasia by investigating aphasic spontaneous speech.
13
A central impairment means impairment in both production and comprehension.
Kolk (1995) presents his adaptation theory, which states that aphasic behaviour reflects adaptation to the disorder and does not
reflect the disorder itself.
14
12
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
2.2. Adverbs
Cann (1993) states that the main function of an adverb is roughly the same as the function of an adjective;
to distinguish a subset with a special characteristic from a larger set of entities. For instance; “I fed the cat
yesterday”, separates a particular ‘cat-feeding’ event that took place the day before the sentence is
uttered from all ‘cat-feeding’ events. However, this is only one function of adjectives and adverbs. For
instance “I am still waiting”, does not separate ‘still-waiting’ events from ‘waiting’ events. The linguistic
category of adverbs therefore can be regarded as a linguistic garbage bin. Consequently, the role of
adverbs in syntax and semantics is not as clear-cut as the role of nouns and verbs for instance.
Adverbs are classified in the category of particles, because no morphology, such as flexion, can be
applied. However adverbs modifying adjectives, in some exceptions, receive morphology. This usually
occurs in informal communication:
(13)
We hebben een hel-e lange wandeling gemaakt.
(We have a very long walk made)
(14)
Het was een erg-e leuke vakantie.
(This was a very amusing vacation)
(from: e-ANS, 2002)
Ernst (2001, in: Nilsen, 2004) claims adverbs either apply to events, propositions or facts. Differences
between these three possible modification domains determine which type of adverb is selected. This
suggests that there are multiple types of adverbs. However, classifying adverbs turns out to be a
challenge, because there are several methods to divide adverbs.
Adverbs are usually divided in two classes; adverbial adjuncts and ‘real’ adverbs. Several subclassifications have been proposed. Alexiadou (2004) mentions a distinction in function; predicate
operators and sentence operators (Thomason and Stalnaker, 1973; in: Alexiadou, 2004). This division is
often referred to as the distinction between VP adverbs and sentence adverbs (Alexiadou, 2004),
illustrated by following examples:
(15)
Cleverly John did not say a word to the angry hooligan.
It was clever of John not to…
Cleverly = a sentence adverb or a sentence operator
(16)
John solved the problem cleverly.
John solved the problem in a clever manner.
Cleverly = a VP adverb or a predicate operator
The e-ANS (elektronische Algemene Nederlandse Spraakkunst, 2002), which is a well known reference
for Dutch grammar, makes use of three ways to classify Dutch adverbs; on the basis of form, meaning and
function. In the function-group the e-ANS distinguishes between ‘term adverbs’, for instance: “thuis,
gisteren” (at home, yesterday) and ‘reference adverbs’ for instance: “daar, toen” (there, then). The
difference between term and reference adverbs is that the first group names things, times or actions in the
here and now, whereas the latter group refers to things, times or actions beyond the here and now, for
instance:
(17)
Gisteren heb ik daar gewandeld.
(Yesterday have I there walked).
In (17) two adverbs are used: yesterday and there. Interpretation of ‘yesterday’ is clear: the day before the
speaker says this sentence. Interpretation of ‘there’ is not that straightforward. In order to interpret ‘there’
correctly, discourse that informs where the speaker has walked is required. According to the e-ANS
‘yesterday’ is thus a term adverb and ‘there’ is a reference adverb; it refers to a location that is known to
both speaker and listener.
Roose (1964) makes a similar distinction, but uses different names; term adverbs are ‘adverbs with a
lexical meaning’ and reference adverbs are called ‘deictic adverbs’. Roose distinguishes another group;
13
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
adverbs without lexical meaning and deictic capacities. This is a group of adverbs that is formed by
combining “er-” with a preposition, resulting in words like “ernaast, erop, erdoor, ertoe, erheen”.
Usually focus of a classification is either on the semantic behaviour of adverbs or on the syntactic
behaviour. Frey and Pittner (1998) and Frey (2003) bridge between syntactic and semantic classifications
of adverbs. They distinguish between five separate groups of adverbs15 in what they call ‘the middle field’16
of a sentence: sentential modifiers, frame/domain modifiers, event external modifiers, event internal
modifiers and process-related modifiers. Their hierarchy is based on the c-commanding properties of the
position where these adverbs are base generated and are presented in Table 1 below:
Adverb class
Restrictions
The base position of a sentence adverb c-commands the base position of all
17
Sentence adverbs
arguments and all other adjuncts .
The base position of a sentence adverb c-commands the base position of the
finite verbal form.
Frame/domain adverbs
The base position of a frame/domain adverb c-commands the base position of the
arguments and the remaining adjuncts, except sentence adverbs.
Event-external adverbs
The base position of an event-external adverb c-commands the base position of
the highest ranked argument.
Event-internal adverbs
The base position of an event-internal adverb is minimally c-commanded by the
base position of the highest ranking argument.
Process-related adverbs
The base position of a process-related adverb minimally c-commands the base
position of the main predicate.
Table 1: C-command relations of adverbs in Frey and Pittner’s hierarchy (from: Frey, 2003).
Although this appears to be a syntactic method of dividing adverbs, a semantic component is present also.
Semantically, adverb classes are distinguished by scopal relations, because scope is important for the
ordering of more adverbs from the same class in one clause.
Frey and Pittner’s and Frey’s hierarchy can not be implemented easily in linguistic research. C-command
restrictions seem quite clear, but determining the base position of adverbs in aphasic speech is
problematic. Although Frey and Pittner provide several tests to determine the basic word order of a
sentence, they do not explain how these rules apply to adverb distribution. Consider for instance the task
of determining the base position of an adverb with multiple legal positions in elliptical speech.
Other classifications, such as the division by the e-ANS (2002) and Roose (1964), are usually vague on
topics like syntax, word order and the status of adverbs. Cinque (1999) provides a clear hierarchy of
adverbs that is related to sentence structure.
2.2.1.
Cinque’s universal adverb hierarchy
Cinque (1999) distinguishes ‘circumstantial’ adverbs, such as means, manner, place, time, company,
reason and purpose adverbs from ‘proper’ adverbs. Circumstantial adverbs do not have a fixed order with
respect to one another, as proper adverbs do. For instance:
(18)
He attended classes [on a different day of the week]temporal [in a different university]locative.
He attended classes [in a different university]locative [on a different day of the week]temporal.
(from: Cinque, 1999)
15
In fact Frey (2003) discusses adjuncts instead of adverbs. Since Frey and Pittner view adverbs as adjuncts, adverbs are used
where Frey and Pittner use adjuncts.
16
Schweikert (2005) regards the middle field as the predicate group plus the confined predicate group.
17
In this restriction the term adjunct is used instead of adverb, because adverbs may c-command frame adjuncts as well.
14
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
(19)
Femke Nouwens
[Gewoonlijk]asp_habitual gaat hij [snel]Asp_celerative naar zijn werk.
(Usually goes he in a hurry to his job)
? [Snel]Asp_celerative gaat hij [gewoonlijk]Asp_habitual naar zijn werk.
(In a hurry goes he usually to his job)
Examples (18) and (19) show the difference between circumstantial adverbials18 and proper adverbs
according to Cinque. The order of the temporal and locative adverbials in (18) is not fixed, because the
adverbials are interchangeable without change of meaning. The order of the habitual and celerative
adverbs in (19) is fixed. Changing their position in a sentence causes odd or unacceptable sentences,
provided no special stress pattern or pauses are used.
Cinque (1999 and 2004) views adverbs as elements that belong to specifier positions. Cinque bases his
claim on the observation that cross-linguistically different classes of AdvP’s and their relative order match
number, type and relative order of functional head morphemes. Secondly, Cinque mentions that AdvP’s
and functional head morphemes are expressed in a similar way in sign language. Thirdly, both AdvP’s and
functional head morphemes appear simultaneously in acquisition.
Opponents of this specifier approach, among others Costa (2004) and Ernst (2004), regard adverbs as
adjuncts. Cinque states that interpreting adverbs as ‘adjuncts’ is the same as interpreting them as
‘accessory appendices to clause structure’. He proposes to consider adverbs as belonging to the
functional categories of a sentence. Cinque states that an adverb is base generated as specifier of a
functional head. The observation that adverbs appear to surface at different locations than their base
position is explained by movement of surface forms of different functional heads.
Cinque claims that adverbs are classified and distributed on syntactic grounds. He argues against the
opinion that semantic scope should be decisive in classifying adverbs and determining distributional
characteristics. However, scope is important for the interpretation of circumstantial adverbs and
adverbials. When a universal quantifier is added to example (18) this point becomes clear:
(20)
a) He attended classes [in each university] [on a different day of the week].
b) [On a different day] of the week he attended classes [in each university].
(adapted from: Cinque, 1999)
The locative adverbial has scope over the time adverbial in (20a) which is reversed in (20b). Change in
the order of the adverbials however changes the meaning. (20a) means that if there were seven
universities, every day of the week he attended classes in a different university. (20b) might mean the
same as (20a), although it might mean that if there are three universities, he attended classes at all three
universities for seven days a week.
2.2.1.1. Levels of functional heads
Cinque distinguishes three clusters of functional heads; mood/modality, tense and aspect. Moods and
modals express the attitude or opinion of the speaker towards the proposition he or she utters. Cinque
distinguishes several types of moods and modals corresponding to distinct types of adverbs, for instance
“misschien” (perhaps) is a specifier of irrealis mood and “gelukkig” (fortunately) specifies evaluative mood.
Mood and modal adverbs occur highest in the syntactic tree.
To describe tense, Cinque adopts a refined version of Reichenbach’s tense system (1947; in: Cinque,
1999) by Vikner (1985; in: Cinque, 1999). Opposed to other theoreticians who view tense as operators,
Reichenbach views tense as relations between times or temporal entities. Reichenbach and others regard
tense as a three-place-relationship between event time (E), reference time (R) and speaking time (S).
These ‘times’ are combined in two-paired relations to form all existing tenses (see appendix II), for
instance: T(anterior) is indicated by E coinciding or preceding R2, T(future) by R2 coinciding or following R1
and T(past) by R1 coinciding or preceding S.
The functional head cluster ‘aspect’ expresses two types of information. The first type expresses the
internal structure of an event (expressed by the predicate and its arguments), so whether it has a
beginning or an end and internal stages. This type distinguishes among activities (walk, row a boat),
18
Another difference Cinque mentions is that circumstantial adverbs are usually realised as PP or NP-adverbials, such as: PP: in the
garden, for three hours and NP: the day after or this way.
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Femke Nouwens
states (know, desire), accomplishments (tie a knot, walk five minutes) and achievements (reach the finish
line, finish writing a thesis) of Vendler’s classical typology (1967; in: Cinque, 1999). Cinque refers to this
first type of information as ‘lexical aspect’.
The second type is referred to as ‘grammatical aspect’ and expresses the way a speaker presents an
event through grammatical means. Examples are given below:
(21)
(22)
(23)
John has run a mile.
Terminative aspect by means of an auxiliary.
John no longer runs a mile.
Terminative aspect with an additional adverb.
John is running a mile.
Continuative aspect by means of an auxiliary.
John still runs a mile.
Continuative aspect by means of an adverb.
John used to run a mile.
Habitual aspect by means of an auxiliary.
John usually runs a mile.
Habitual aspect by means of an adverb.
(adapted from: Cinque, 1999)
Adverbs in the second sentences of the pairs of examples convey similar information as auxiliaries and
verb inflections in the first examples.
2.2.1.2. The adverb hierarchy
Cinque proposes the following hierarchy of functional heads with corresponding locations for ‘proper’
adverbs:
Mood speech act > Mood evaluative > Mood
evidential
> Mod epistemic > T(Past) > T(Future) >
Mood irrealis > Mod alethic > Asp habitual > Asp repetitive(I) > Asp frequentative(I) > Mod volitional > Asp
celerative(I)
>
T(Anterior) > Asp terminative > Asp continuative > Asp perfect /imperfect(?) > Asp retrospective > Asp proximative >
Asp durative > (?) Asp
generic/progressive
> Asp prospective > Asp Sg Completive(I) > Asp Pl Completive > Voice >
Asp celerative(II) > Asp repetitive(II) > Asp frequentative(II) > Asp Sg Completive(II)
There are two question marks in the hierarchy. Cinque has sufficient evidence to locate the adverb
‘always’ between continuative and retrospective aspect. However, he is not certain whether this adverb
belongs to perfect/imperfect aspect. This does not weaken the hierarchy, because location in the
hierarchy is more important than the name of the functional head.
Another question mark is added to generic/progressive aspect. Cinque is not certain which adverbs
correspond to this functional head. He has some evidence that points towards adverbs such as
“characteristically”.
In Table 2 below, various functional heads in the hierarchy are presented with English and Dutch
examples of matching adverbs. More information about functional heads and corresponding adverb types
can be found in Appendix I.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
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Cinque’s adverb distribution
English examples
Dutch translations
frankly
Mood speech act
eerlijk, ronduit gezegd
fortunately
Mood evaluative
gelukkig
allegedly
Mood evidential
zoals beweerd wordt
probably
Modality epistemic
waarschijnlijk
once
T(Past)
eens, toen, in die tijd
then
T(Future)
dan, tegen die tijd
perhaps
Mood irrealis
misschien, mogelijk
Modality alethic (necessity/possibility) necessarily, possibly
noodzakelijkerwijs, mogelijkerwijs
usually
Aspect habitual
gewoonlijk, doorgaans
again
Aspect repetitive(I)
weer, opnieuw
often
Aspect frequentative(I)
vaak, dikwijls
intentionally
Modality volitional
opzettelijk
quickly
Aspect celerative(I)
snel
already
T(Anterior)
reeds, al
no longer
Aspect terminative
niet meer
still
Aspect continuative
nog (altijd), nog steeds
always
Aspect perfect/imperfective (?)
altijd, steeds
just
Aspect retrospective
net (tense), nog
soon
Aspect proximative
spoedig, vroeg
briefly
Aspect durative
kort
(?) Aspect generic/progressive
characteristically
karakteristiek, typisch
almost
Aspect prospective
bijna, nagenoeg
completely
Aspect Singular Completive(I)
compleet, helemaal
19
tutto
Aspect Plural Completive
geheel, heel, allemaal
well
Voice
goed
fast/early
Aspect celerative(II)
snel/vroeg, spoedig
again
Aspect repetitive(II)
weer, opnieuw
often
Aspect frequentative(II)
vaak, dikwijls, meestal
Aspect Singular Completive(II)
completely
compleet, geheel
Table 2: Dutch and English examples of adverbs in Cinque’s hierarchy (adapted from: Cinque, 1999).
Cinque remarks that the hierarchy is not complete. Cinque has discovered differences between languages
in the way functional categories are expressed (either by affixation or separate words, like adverbs).
Consequently, not all functional heads can be located in the hierarchy.
If Cinque’s claim is correct, the following must be true as well: if an adverb appears at a certain position of
a functional category, this functional category must be present either overt or covert in the syntactic
structure, i.e. it can not be impaired (or pruned from the syntactic tree). Therefore, it should be possible to
derive a subset of available functional categories in aphasic speech from the adverb distribution, as
claimed by Alexiadou and Stavrakaki (2006, see also section §2.1.4). Haider (2000) interprets Cinque’s
theory in the following way: “The order of adverbials in a clause thus reflects the nesting of functional
projections. Since there must be a separate functional projection for each adverbial, whose semantics is
identified with the semantic value of the silent functional head, each adverbial gives rise to a functional
projection”.
The Tree Pruning Hypothesis (see § 2.1.1) claims that pruning of the syntactic tree causes verbs to be
uninflected in Broca’s aphasia. If however finite verbs are observed, this would imply that the IP-node
above the pruning location was available at the time the clause was built. The same holds for presence of
a high adverb.
19
Cinque provides an Italian example, because Plural Completive Aspect does not exist in English. In Dutch ‘allemaal’ is a good
example: ‘Wij hebben het allemaal opgegeten’ (we have it completely eaten and we all have eaten it).
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2.2.2.
Femke Nouwens
An alternative classification of Cinque’s adverb types
Cinque’s adverb hierarchy corresponds well to the Tree Pruning Hypothesis, since both depend on a
similar syntactic tree. However, it would be interesting to divide these adverbs according to a more
semantic approach.
Two natural classes of adverbs exist in Cinque’s hierarchy: adverbs with an adjective as basis and
adverbs that are not based on an adjective. Jackendoff (1972) states that the class of adverbs based on
adjectives can be divided into two groups by examining whether adverbs are gradable. This can be done
by posing the following question: How ADVERB did someone VERB?, as in the examples below:
(24)
The man ran quickly.
How quickly did he run?
(25)
Frankly, I am telling you this.
* How frankly did you tell me this?
Another class of adverbs that have an adjective as their basis, are adverbs that can take –wijs/-erwijs/gewijs/etc. (-wise) and a class of adverbs that can not (Øystein Nilsen, p.c.). For example, adverbs like
“mogelijk” (possibly) can be combined with “–erwijs”; “mogelijkerwijs” (in a possible way). This is
impossible with adverbs like “altijd” (always); “ *altijderwijs/altijdsgewijs” ( *in an always way).
(26)
Mogelijk komt zij niet op tijd.
(Possibly comes she not on time)
Mogelijkerwijs komt zij niet op tijd.
(Possibly comes she not on time)
(27)
Zij komt altijd te laat.
(She comes always too late)
* Altijdsgewijs komt zij te laat.
(It is always that comes she too late)
It turns out that the group of adverbs with an adjective as base can be divided into two groups by applying
these two methods. The ‘-erwijs’-method distinguishes highest adverbs and the ‘how...?’-method
distinguishes remaining adverbs corresponding to various lower functional heads.
A large group of adverbs in Cinque’s hierarchy is not based on an adjective. These adverbs share a
temporal aspect. A division is made into three groups. Differences are explained by the following
examples:
(28)
Can you believe it, he always smokes.
(29)
Can you believe it, he still smokes.
(30)
Can you believe it, he smoked then.
The division is made between adverbs that can be interpreted always (28) and adverbs that require
additional operations, such as accommodation (29), reference or interpretation of discourse (30). Hence,
the following three groups of ‘temporal’ adverbs are formed:
i.
Always interpretable: often, always
ii.
Interpretable with accommodation: again, no longer, still
iii.
Impossibly interpretable without context: then, once
For reference and discourse dependencies a proper working syntactic and semantic system is necessary.
Operations of these systems can be time consuming, as explained by the following examples:
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Femke Nouwens
(31)
[Little Red Riding Hood]1 went to [her grandmother]2. When she2 opened the door she1 gave her2
(32)
Cinderella went to the Prince’s ball. When the Prince saw Cinderella, the Prince’s jaw dropped.
her1 basket of cookies.
For the reader’s convenience all pronouns in (31) are marked with a subscript indicating the matching
antecedent. Nevertheless interpretation of (31) is probably more time consuming than (32).
One might wonder why we use these ‘difficult’ adverbs very often if they require more work than other
adverbs. Normally we would not say (32), instead pronouns would be used; ‘When the Prince/he saw her,
his jaw dropped’. The same goes for adverbs:
(33)
I have to go and find a serious job as a clinical linguist soon. When I have to go find a serious job as
clinical linguist, my thesis will be finished.
(34)
I have to go and find a serious job as a clinical linguist soon. Then my thesis will be finished.
In example (34) the adverb ‘then’ replaces the temporal adverbial clause ‘when I have to go find a serious
job as a clinical linguist’. Temporal adverbs requiring discourse and reference operations replace an entire
clause and are very efficient. Normally the syntactic system operates well, so it will not be noticed that the
system performs additional operations during the use of adverbs that can not be interpreted without
context. When the syntactic system is damaged, these operations will be too costly to be executed
correctly. The same might be true for adverbs that require accommodation, because an additional
operation must be performed in order to interpret these adverbs.
A number of adverbs from Cinque’s hierarchy do not match a temporal group and are not based on an
adjective. Therefore, the final group in the alternative division is negatively defined; the non-adjective/nontemporal group.
With the above mentioned guidelines, adverbs belonging to Cinque´s hierarchy have been divided into the
following alternative groups:
Group 1: based on an adjective and combines with ‘-erwijs/-wijs/-gewijs’
Group 2: based on an adjective and questionable with ‘how...?’
Group 3: ‘temporal’, always interpretable
Group 4: ‘temporal’, with accommodation interpretable
Group 5: ‘temporal’, impossibly interpretable without context
Group 6: non-adjective/non-temporal
It is important to notice that this alternative division is not compatible with Cinque’s adverbs hierarchy.
2.3. Outline
The following research questions are formulated to guide the present study. Predictions are presented
also.
I
Is Cinque’s adverb hierarchy compatible with the Tree Pruning Hypothesis?
i. If the TPH is correct, Broca’s aphasics will produce more adverbs from the low region
in Cinque’s hierarchy than from the high region. Consequently, a preference for lower
adverb groups should be observed.
ii. The severity metric predicts that Broca’s aphasics produce relatively less adverbs if
these adverbs are located higher up the syntactic tree; i.e. the chance of the tree to
be pruned at a functional head increases if the functional head is located higher up
the syntactic tree.
iii. If the TPH is correct, a significant difference between the two control groups
(Wernicke’s aphasics and unimpaired controls) and Broca’s aphasic group regarding
the proportion of higher groups of adverbs will be observed.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
iv. A significant difference between one group of adverbs and all adverb groups located
higher in the syntactic tree in Broca’s aphasia implies the pruning location.
v. If the TPH is correct a strong positive correlation between presence of a high adverb
and a finite verb in Broca’s aphasics’ spontaneous speech will be observed, because
when a high adverb is realised the corresponding functional head is intact.
II
Is the alternative classification of Cinque’s adverb hierarchy compatible with the Tree Pruning
hypothesis?
i. Given that the alternative division does not follow Cinque’s hierarchy and is more
semantically defined, no significant differences between groups of adverbs will be
observed in the Broca’s aphasic group.
ii. Since the alternative classification does not follow the hierarchy of a syntactic tree, a
significant difference between control subjects and Broca’s aphasics will indicate a
different underlying deficit of Broca’s aphasia than the TPH suggests.
III
Is a hierarchy observed within the alternative classification?
i. Group 1 separates adverbs based on adjectives located highest in the syntactic tree
from group 2 adverbs based on adjectives located in the remaining lower region. The
prediction is that Broca’s aphasics will produce significantly less group 1 adverbs than
group 2 adverbs.
ii. A hierarchy in the temporal adverbs regarding degree of discourse dependency is
expected in the Broca’s aphasic group; group 5 least frequent, group 4 less frequent
than group 3 and group 3 most frequent.
iii. Significant differences will be observed between groups of subjects.
IV
Which regression model will fit the data best; a model based on the hierarchical classification
or a model based on the alternative classification?
i. If the model of Cinque´s adverb hierarchy fits the data best, the underlying deficit in
Broca’s aphasia is likely to have an effect on syntactic processes. This would lend
support to the TPH.
ii. If the model of the alternative classification fits the data best, the underlying deficit in
Broca’s aphasia will probably have an effect on semantic processes. This would be an
argument against the TPH.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Chapter 3
Methodology
3.1. Participants
The main goal of the present study is to investigate adverb distribution in Broca’s aphasics’ spontaneous
speech. Because little is known about adverb distribution in spontaneous speech in general, two control
groups are added; one consisting of unimpaired controls and the other consisting of Wernicke’s aphasics.
Eighteen aphasic subjects participated in an extensive study on aphasia therapy, the Rotterdam Aphasia
Therapy Study, RATS, at Erasmus MC in Rotterdam (Doesborgh et al., 2004 and Visch-Brink, 2006).
RATS is a randomized controlled trail in which aphasic subjects are treated with either functional therapy
or cognitive-linguistic therapy. In RATS-1 the effect of a phonological cognitive-linguistic therapy method
(FIKS) was compared to the effect of a semantic cognitive-linguistic therapy (BOX). In RATS-2 the effect
of both cognitive-linguistic therapy methods combined is investigated.
Eight Broca’s aphasics and ten Wernicke’s aphasics were selected based on the AATP20, which is a
measure provided by the Dutch version of the Aachener Aphasia Test (AAT; Graetz et al, 1992). One
Broca’s aphasic subject was recruited at a rehabilitation centre in Delft. In a rehabilitation centre in Den
Haag a second Broca’s aphasic subject was recruited. Their aphasia syndrome was diagnosed with the
AATP.
20
AATP is a computer program and interprets raw AAT results into a classification of aphasia syndromes and a measure for severity
of aphasic deficits.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Unimpaired controls were selected from a larger group of controls that were used for standardization of
the AAT. Table 3 represents age and sex of the participants:
Broca
Age
Sex
Wernicke
Age
1
58
M
1
57
2
26
F
2
83
3
65
M
3
70
4
60
F
4
74
5
81
M
5
72
6
47
F
6
80
7
62
F
7
76
8
64
M
8
37
9
73
F
9
47
10
78
F
10
63
Table 3: Characteristics of the test population.
Sex
M
M
F
M
M
F
M
F
M
M
Unimpaired
1
2
3
4
5
6
7
8
9
10
Age
74
83
68
79
81
59
67
75
71
64
Sex
M
F
F
F
F
M
M
M
F
M
3.2. Data
RATS-2 monitors progression by administering an extended test battery at three weeks, three months and
six months post onset. The Dutch version of the AAT is administered six weeks post onset. The first item
of this test is a semi-standardized interview based on four standard topics. Consequently, samples of
spontaneous speech are maximally comparable.
Samples of spontaneous speech with a duration of at least ten minutes were collected with the AAT. The
speech therapist is instructed not to interfere in order to gain as much spontaneous speech as possible.
Spontaneous speech samples were transcribed according to guidelines of the VKL21. The first 100
utterances for analysis will be used. An utterance is defined by the VKL as consisting of a grammatical
unity, with a decreasing intonation pattern and a clear pause at the end. Conjunctions22 and indirect
speech do not qualify as utterance boundaries. Words like “ja” (yes), “nee” (no) and “nou” (well) are
excluded from the utterances.
Collecting samples of 100 utterances in the Broca’s aphasic group was difficult. Samples were completed
with spontaneous speech samples recorded at a later point in time. These additional samples were
checked for any significant recovery by a second AATP. Samples are comparable and representative of
the speech of these subjects.
For two subjects adding this second AAT sample was not sufficient for two subjects. Therefore, these
samples are completed with recordings of the ANTAT (Amsterdam-Nijmegen Test voor Alledaagse
Taalvaardigheden; Blomert et al, 1995). This test measures everyday communication using ten different
scenarios; for instance: rescheduling an appointment at the doctor’s by telephone. Subjects are asked to
react verbally to the scenarios. This can be viewed as semi-spontaneous speech.
Adverbs, relevant in Cinque’s hierarchy, are marked in the samples. Hereafter, adverbs are assigned to a
class of adverbs that occurs in Cinque’s adverbs hierarchy. Cinque’s hierarchy is divided in six
hierarchical clusters, i.e. adverb groups.
Since large differences between groups of subjects regarding frequency of adverb production were found,
raw data were not used for analysis; instead, proportions of adverb groups were analysed. Relative data
were calculated using the following formula:
Proportion per adverb group X23 =
adverbs per adverb group X /
all adverbs
Overt presence of adverbs in spontaneous speech was assumed to be related to the presence of
functional heads, meaning that these functional heads are accessible during speech production. Analysis
of the presence or absence of other elements related to the functional heads was used to test this
assumption. As already mentioned in the section discussing the Tree Pruning Hypothesis, finite verbs are
expected to be affected in Broca’s aphasia by pruning. Presence or absence of a finite verb has to
21
VKL = Vereniging voor Klinische Linguïstiek, the Dutch society for clinical linguists (see internet resources).
The conjunction “en” (and) is not an utterance boundary if it is used in an enumeration.
23
X can be replaced by the number of the adverb group of interest.
22
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
correlate with presence or absence of higher adverb types if the TPH and Cinque are correct. The
proportion of finite verbs in sentences with an adverb was used to test this assumption. This proportion
was determined by the following formula:
Proportion finite verbs =
sentences plus adverb, plus finite verb /
sentences plus adverb
Several statistical analyses using statistical software were performed. GLM repeated measures was used
to examine whether significant effects of adverb group, subject group and interaction effects of subject
group and adverb group could be found.
To explore whether results in the adverbs groups indeed cohere with the presence or absence of
functional heads several correlation analyses were conducted with proportions of finite verbs in all
sentences with an adverb as a dependent variable and groups of adverbs as independent variables.
Regression analysis was performed to examine which grouping explains most of the variance in
production of finite verbs. Regression analysis provided information on which model explained the largest
proportion of variance in the dependent variable. Results of these analyses will be discussed in the
following chapter.
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Femke Nouwens
Chapter 4
Results
Only few adverbs were produced by Broca’s aphasics per separate functional head of Cinque’s hierarchy.
Analyses of all separate adverb types would probably not lead to sufficient significant results to base clear
conclusions on. Therefore, Cinque’s adverb hierarchy was divided into six equal groups following the
hierarchy. The 29 adverb types in the hierarchy could not be divided into equal groups. The division
between the first and the second group was placed after epistemic mood and not between T(past) and
T(future). If these two functional heads would have been divided into separate groups, the proportion of
past versus future temporal adverbs might affect relations between group 1 and 2. The following clusters
or groups of functional heads were used:
Group 1: Mood speech_act, Mood evaluative, Mood
evidential, Mod epistemic
Group 2: T(past), T(future), Mood irrealis, Mod alethic, Asp
habitual
Group 3: Asp repetitive(I), Asp frequentative(I), Mod volitional, Asp celerative(I), T(anterior)
Group 4: Asp terminative, Asp continuative, Asp perfect/imperfect, Asp retrospective, Asp proximative
Group 5: Asp durative, Asp generic/progressive, Asp prospective, Asp Sg Completive(I), Asp Pl Completive
Group 6: Voice, Asp celerative(II), Asp repetitive(II), Asp frequentative(II) , Asp
Sg Completive(II)
Group 1 corresponds to a cluster of functional heads located highest in the syntactic tree, whereas group
6 matches the cluster of lowest functional heads.
The adverb groups above are based on syntactic features alone, i.e. corresponding functional heads. In
order to use the data for an additional more semantically based analysis, adverbs from Cinque’s hierarchy
were also grouped using an alternative method. As explained in section §2.2.2, this division is based on
24
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Jackendoff’s (1972) and Nilsen’s (p.c.) approach and is not related to distinct locations in the syntactic
tree. This alternative division is repeated below:
Group 1: based on an adjective and combines with ‘-erwijs/-wijs/-gewijs’
Group 2: based on an adjective and questionable with ‘how...?’
Group 3: ‘temporal’, always interpretable
Group 4: ‘temporal’, with accommodation interpretable
Group 5: ‘temporal’, impossibly interpretable without context
Group 6: non-adjective/non-temporal
Analyses were performed to examine whether significant differences between groups of adverbs per
subject group occurred and whether differences between groups of subjects per adverb group were found.
Analyses are schematised in Figure 4 below:
Figure 4: Analysis scheme of comparisons of adverb groups and subject groups.
25
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
4.1. Results of Cinque’s hierarchical grouping
Adverb groups corresponding to Cinque’s hierarchy were analysed first, because the focus of the present
study is on this division. In Figure 5 mean scores of the six adverb groups are represented for each
subject group. Bear in mind that the TPH predicts that lower adverb groups will be produced more
frequently in the Broca’s aphasic group, since functional heads corresponding to higher adverbs are
inaccessible. According to the refined TPH by Alexiadou and Stavrakaki (2006) and the TPH with severity
metric, a gradual increase of adverb production is expected in Broca’s aphasia as adverbs are located
lower in the syntactic tree.
Figure 5: Comparison of groups of adverbs per subject group; hierarchical division.
The production of group 6 adverbs is highest in Broca’s aphasics. There is a gradual increase of mean
scores in Broca’s aphasics as adverb groups are located lower in the syntactic tree, except for group 2
adverbs. Group 2 adverbs turned out to be quite frequently used by Broca’s aphasics.
The high incidence of group 2 adverbs is apparent in mean scores of Wernicke’s aphasics and unimpaired
controls also. However, no clear pattern is discernable in the remaining groups of adverbs.
In Figure 6 groups of subjects are combined per group of adverbs to highlight scores for each adverb
group.
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Femke Nouwens
Figure 6: Comparison of groups of subjects per group of adverbs; hierarchical division.
Figure 6 shows that Broca’s aphasics produced fewer adverbs from group 1, 2 and 4 than unimpaired
controls and Wernicke’s aphasics. Broca’s aphasics produced relatively more group 5 and group 6
adverbs than Wernicke’s aphasics and unimpaired controls. Preference for group 6 adverbs in Broca’s
aphasics and preference for group 2 adverbs in unimpaired controls stand out in Figure 6. Strikingly, all
subject groups produced nearly equal proportions of group 3 adverbs.
Examination of proportions per group of adverbs reveals four distinct preference patterns. Group 2 and
group 4 adverbs revealed that relative proportion of adverbs of those groups increases gradually between
subject groups. Broca’s aphasics produced group 2 and 4 adverbs fewer than Wernicke’s aphasics and
unimpaired controls and Wernicke’s aphasics produced fewer group 2 and 4 adverbs than unimpaired
controls. Opposite preference patterns are visible in group 5 and group 6 adverbs. Broca’s aphasics prefer
these adverbs more than Wernicke’s aphasics and unimpaired controls. Wernicke’s aphasics prefer these
groups of adverbs more than unimpaired controls.
Group 1 and group 3 adverbs do not reveal a pattern between subject groups. In fact, these adverb
groups were produced relatively infrequent. Figure 7 shows which patterns of adverb distribution occur per
subject group:
27
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 7: Adverb distribution; hierarchical division
Figure 7 reveals a similar pattern in all subject groups regarding the four highest adverb groups. Broca’s
aphasics produce fewer adverbs of group 1, 2 and 4 than both Wernicke’s aphasics and unimpaired
controls. Figure 7 shows also that Wernicke’s aphasics produce fewer of these adverbs than unimpaired
controls. This pattern is reversed for the lowest two adverb groups; group 5 and 6. Broca’s aphasics
produced more group 5 and 6 adverbs than Wernicke’s aphasics and unimpaired controls. Wernicke’s
aphasics produced more of those adverbs than unimpaired controls. Remarkably, it appears that all
subject groups do not favour group 3 adverbs.
In the following sections analyses to determine significant differences between subject and adverb groups
are presented.
4.1.1.
Group comparisons by means of analysis of variance
GLM repeated measures with groups of adverbs as within-subjects factor and groups of subjects as
between-subjects factor yielded the following results:
24
MEAN SQUARE F
SOURCE
TYPE III SUM OF SQUARES DF
Adverb group
12123.346
3.080
3936.469
17.308
Adverb group * Subject group 4926.541
6.159
799.833
3.517
Error (adverb group)
18912.004
83.153 227.437
Table 4: Results of GLM repeated measures, within subject effects; hierarchical division.
P
.000
.003
Table 4 shows that mean proportions of adverbs are significantly affected by adverb group; F (3.080,
83.153) = 17.308, p < .05. On average, significant differences between mean proportions of produced
adverbs show up in at least two of the six adverb groups. Figure 8 below clarifies this result, revealing a
pattern with clear differences between adverb groups averaged in all subject groups.
24
Degrees
of freedom are corrected using the Greenhouse-Geisser correction ( = .616), because the assumption of sphericity is
2
violated;
(14) = 41.043, p < .05.
28
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 8: Mean proportions of adverb production per adverb group; hierarchical division.
A significant interaction between adverb groups and subject groups was found; F (6.159, 83.153) = 3.517,
p < .05, meaning that the significant effect of subject group on the mean proportion of produced adverbs
depends on at least one adverb group. Looking at the pattern of mean proportions of realised adverb
groups we see almost similar patterns in al three subject groups for group 1, group 2, group 3 and group 4
adverbs. In all these adverb groups the highest mean proportion was realised by unimpaired controls,
followed by Wernicke’s aphasics. Broca’s aphasics produced these adverb groups least frequently.
However, group 5 and 6 were most frequently produced by Broca’s aphasics, followed by Wernicke’s
aphasics. Unimpaired controls least favoured these adverb groups.
A test of between-subjects effects yielded the following results:
SOURCE
TYPE III SUM OF SQUARES DF MEAN SQUARE F
9
Intercept
8333.444
1
8333.444
9.00×10
6
7
Subject group
1.30×10
2
6.48×10
.670
Error
2.61×105
27 9.67×10 7
Table 5: Results of GLM repeated measures, between subjects effects; hierarchical division.
P
.000
.520
Table 5 shows no significant effect of subject groups; F (2) = .670, p < .05. However, a significant effect of
the intercept of subject group and adverb group occurred, F (1) = 9.00×109, p < .05. Isolated subject
groups did not differ from each other, whereas they did differ regarding production of at least one group of
adverbs. Differences between adverb production can be attributed to differences between subjects.
Post hoc analyses did not show relations between separate levels of between and within-subject
variables. Therefore, differences between subject groups regarding adverb groups were analysed with
95% confidence intervals of means per subject*adverb group combination. If two confidence intervals do
not overlap it is concluded with 95% certainty that means in that cell significantly differ25. Table 6 shows
the confidence intervals:
25
This unconventional method was pointed out to me by Hugo Quené. However the repeated measures factor is not accounted for.
A considerably more complicated method would be better for this type of post-hoc analysis. However, the method used is sufficient.
29
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
GROUP 1
GROUP 2
GROUP 3
GROUP 4
Broca’s aphasia
[-1.47; 13.04] [10.92; 35.40] [2.43; 16.82] [5.84; 21.97]
Unimpaired controls [6.71; 12.99] [35.93; 49.23] [5.30; 10.49] [18.31; 26.59]
Wernicke’s aphasia
[3.97; 17.88] [22.55; 37;03] [4.65; 11.87] [12.46; 20.36]
Table 6: Post hoc 95% confidence intervals; hierarchical division.
Femke Nouwens
GROUP 5
[6.31; 27.59]
[2.92; 6.67]
[9.83; 17.04]
GROUP 6
[12.42; 48.72]
[8.29; 16.57]
[12.67; 29.69]
Table 6 demonstrates no significant differences between groups of adverbs in Broca’s aphasics. However,
the pattern in Figure 7 did reveal differences. When confidence intervals in the unimpaired control group
are compared, many significant differences are observed. Only groups that did not differ significantly are
mentioned; group 1 and 3, group 1 and 6, group 3 and 6 and group 3 and 5. Wernicke’s aphasics showed
significant differences between group 2 and all other groups except for group 6, because group 2 was
produced very frequently. In addition, group 3 is significantly less used than group 4 and 6.
When groups of subjects are compared per adverb group we see that Broca’s aphasics produced
significantly fewer group 2 adverbs than unimpaired controls and Wernicke’s aphasics produced
significantly more group 5 adverbs than unimpaired controls. However Figure 7 shows that Broca’s
aphasics produce even more group 5 adverbs than Wernicke’s aphasics, but no significant difference with
unimpaired controls is observed. This finding is probably caused by large variation within the Broca’s
aphasic group. Confidence intervals take standard deviations into account and therefore are more
conservative than GLM.
4.1.2.
Correlation analysis
In addition to comparisons of adverb groups and subject groups the aim was to verify whether Tree
Pruning effects occurred in the data. For this purpose an analysis was conducted in addition to the
analysis of adverb distribution. Production of sentences with an adverb and a finite verb was examined in
relation to production of sentences with an adverb without a finite verb, i.e. either an infinitive is produced
or the verb is omitted.
The proportion of finite verbs indicates how many syntactic trees were built at least up to TP. According to
Friedmann and Grodzinsky (1997) TP can not be reached when the syntactic tree is pruned.
Consequently, finite verbs will be affected by tree pruning in Broca’s aphasia. If finite verbs are indeed
affected by tree pruning a correlation between adverb groups and realization or omission of finite verbs
will be observed. This means that adverb groups are regarded a predictor for proportion of finite verbs and
vice versa. A dependent t-test was conducted to examine whether subject groups differed significantly on
production of sentences with an adverb and a finite verb. Results are presented in Table 7 below:
COMPARISON
T
DF
SIGNIFICANCE LEVEL (ONE TAILED)
Broca – unimpaired
-5.775 9
.000
Broca – Wernicke
-3.397 9
.004
Wernicke – unimpaired
-3.197 9
.006
Table 7: Results of the dependent t-test for proportion finite verbs.
Significance levels in Table 7 reveal a hierarchy between subject groups. Broca’s aphasics produced
significantly less sentences with an adverb and a finite verb than Wernicke’s aphasics; t (9) = -3.397, p <
.05 and unimpaired controls; t (9) = -5.775, p < .05. Wernicke’s aphasics produced significantly less
sentences with an adverb and a finite verb than unimpaired controls; t (9) = -3.197, p < .05. This hierarchy
is visualised in Figure 9:
30
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 9: Proportion of sentences with a finite verb and an adverb.
A correlation analysis with proportion of finite verbs as a dependent variable and groups of adverbs as
independent variables was conducted to test whether presence of a finite verb had an effect on presence
of a specific type of adverbs (and vice versa). Table 8 shows results for the hierarchical grouping
according to Cinque’s hierarchy:
Subjects
Broca’s aphasia
26
Correlating groups
Correlation coefficient
Group 1
Positive
Group 2
Positive
Group 3
Negative
Group 4
.589
Group 5
Positive
Group 6
- .710
Unimpaired controls
Group 1
Negative
Group 2
Positive
Group 3
Negative
Group 4
Negative
Group 5
Negative
Group 6
Negative
Wernicke’s aphasia
Group 1
Negative
Group 2
.792
Group 3
- .640
Group 4
Positive
Group 5
- .659
Group 6
Negative
Table 8: Results of correlation analyses; hierarchical division.
27
Significance level
Non-significant
Non-significant
Non-significant
.037
Non-significant
.011
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
.003
.023
Non-significant
.019
Non-significant
In Broca’s aphasics, group 6 correlates significantly negatively with proportion of finite verbs; R = - .710, p
< .05. If an adverb of group 6 is realized chance of observing a sentence with an adverb and a finite verb
significantly decreases and chance of observing a sentence with an infinitive or no verb increases. The
opposite effect is observed in group 4 adverbs; R = .589, p < .05. If a group 4 adverb is present chance of
realising a finite verb significantly increases.
26
27
This coefficient represents Pearson’s correlation coefficient.
This is the significance level for the one-tailed test.
31
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
No significant correlation effects in unimpaired controls were observed. Therefore, it is highly unlikely that
a relation between presence of any type of adverbs and realisation of a finite verb exists. This implies that
finite verbs are produced regardless of realization of an adverb.
Three significant correlation effects were found in Wernicke’s aphasics. Group 2 adverbs correlate
significantly positive with proportion of finite verbs; R = .792, p < .05. Group 3 and group 5 adverbs
correlate significantly negative with production of finite verbs, respectively; R = - .640 and R = - .659,
p < .05.
4.2. Results of an alternative grouping of Cinque’s adverb hierarchy
The alternative division of Cinque’s hierarchy according to Jackendoff (1972) and Nilsen was analysed
similarly to the hierarchical grouping. Figure 10 shows relative production of groups of adverbs28 per
subject group:
Figure 10: Comparison of adverb groups per subject group; alternative division.
Group 2 adverbs were produced relatively frequent in the Broca’s aphasic group and group 5 adverbs
frequent in unimpaired controls. No such peaks were observed in the Wernicke’s aphasic group. This
subject group showed a more even distribution of adverb proportions.
Figure 11 below shows relative production between subject groups per adverb group:
28
Group names refer to the following classes: group 1 = ‘-erwijs’-group, group 2 = ‘how...?’-group, group 3 = ‘temporal’, always
interpretable, group 4 = ‘temporal’, with accommodation interpretable, group 5 = ‘temporal’, impossibly interpretable without context
and group 6 = ‘non-adjective and non-temporal’.
32
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 11: Comparison of subject groups per adverb group; alternative division.
Figure 11 shows that Broca’s aphasics, more than other subject groups, produced group 2 adverbs
frequently. Group 5 adverbs were preferred by unimpaired controls compared to Broca’s and Wernicke’s
aphasics. Wernicke’s aphasics and unimpaired controls produced group 1 adverbs relatively similar.
When group 3 and group 5 adverbs are compared we see a hierarchy between groups of subjects;
Broca’s aphasics produced both adverb groups relatively fewer than Wernicke’s aphasics and unimpaired
controls and Wernicke’s aphasics again fewer than unimpaired controls. This pattern is reversed when we
look at group 2 adverbs.
Patterns of adverb distribution per subject group are schematized in Figure 12 below:
33
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 12: Adverb distribution; alternative division.
Adverb distributions in this alternative division of Cinque’s adverb hierarchy do not show the clear patterns
as observed in the hierarchical division. When comparing Broca’s aphasics to unimpaired controls, a
nearly opposite pattern is observed. Broca’s aphasics show a peak at the second adverb group, whereas
unimpaired controls show a nadir there. For group 5 this is reversed. In the following section it is examined
whether these differences are significant.
4.2.1.
Group comparisons by means of analysis of variance
Three by six GLM repeated measures was used to explore whether a significant effect of subject group
and adverb group occurs. Groups of adverbs were used as within subject variable and subject groups as
between subjects variable. Table 9 below shows results of this analysis:
29
SOURCE
TYPE III SUM OF SQUARES DF
MEAN SQUARE
Adverb group
5252.871
3.208
1637.582
Adverb group * Subject group 5460.560
6.415
851.164
Error (adverb group)
20423.909
86.608 235.820
Table 9: Results of GLM repeated measures, within subjects effects; alternative division.
F
6.944
3.609
P
.000
.002
Table 9 confirms a significant effect of adverb group on relative production of adverbs; F (3.208; 86.608) =
6.944, p < .05. There are at least two groups of adverbs that differ significantly on mean proportion of
produced adverbs, as can be seen in Figure 13 below:
29
Degrees
of freedom are corrected using the Greenhouse-Geisser correction ( = .642), because the assumption of sphericity is
2
violated;
(14) = 35.675, p < .05.
34
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Figure 13: Mean proportions of adverb production per adverb group; alternative division.
A significant interaction was also found between adverb group and subject group; F (6.415; 86.608) =
3.609, p < .05. Variance in proportions of produced adverbs per adverb group depends on differences
between subject groups. Consequently, at least two subject groups differ significantly on at least two
adverb groups. Figure 12 suggests that all subject groups differ on all adverb groups. However, a
similarity is observed when we compare Wernicke’s aphasics to Broca’s aphasics regarding adverb
groups 4, 5 and 6. Unimpaired controls appear to behave opposite of Broca’s aphasics concerning group
1, group 2, group 3, group 4 and group 5 adverbs.
The main effect of subject group was tested also. Table 10 shows the results:
SOURCE
TYPE III SUM OF SQUARES DF MEAN SQUARE F
9
Intercept
8333.111
1
8333.111
7.00×10
7
7
Subject group
7.41×10
2
3.7×10
.321
Error
3.11×105
27 1.15×10 6
Table 10: Results of GLM repeated measures, between subject effects; alternative division.
P
.000
.728
Table 10 shows no significant effect of subject group on mean production per adverb group; F (2; 27) =
.321, p > .05. The effect of the intercept between subject groups and adverb groups is significant; F (1, 27)
9
= 7.00×10 , p < .05, meaning that subject groups only differ from each other when adverb production is
considered.
35
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
A post hoc test of 95% confidence intervals was administered to examine group differences. Confidence
intervals used for this post hoc procedure are presented in Table 11:
GROUP 1
GROUP 2
GROUP 3
GROUP 4
Broca’s aphasia
[1.74; 14.78]
[15.69; 54.20] [3.03; 14.27]
[9.15; 32.34]
Unimpaired controls [13.27; 21.22] [5.85; 14.38]
[13.33; 22.57] [14.22; 24.32]
Wernicke’s aphasia
[6.45; 26.42]
[8.85; 22.75]
[7.15; 18.28]
[17.00; 28.85]
Table 11: Post hoc 95% confidence intervals; alternative division.
GROUP 5
[6.39; 29.57]
[25.16; 36.78]
[15.40; 28.51]
GROUP 6
[1.41; 17.42]
[2.53; 6.36]
[7.29; 13.04]
Examination of overlap between confidence intervals reveals significant differences between groups.
When confidence intervals between subject groups per adverb group are compared, we see that Broca’s
aphasics produce significantly more group 2 adverbs than unimpaired controls. Comparison of confidence
intervals of subject groups regarding group 6 adverbs reveals significant differences between Wernicke’s
aphasics and unimpaired controls; unimpaired controls produce these adverbs less.
The peak for group 2 adverbs in the Broca’s aphasic group in Figure 11 is significant, because group 2 is
significantly larger than group 1 and group 3. Intervals in the unimpaired group show that group 5 adverbs
are more frequently produced than all other groups of adverbs. In addition, groups 1, 3 and 4 are
significantly more frequently produced than group 6. Wernicke’s aphasics produce group 6 adverbs
significantly fewer than group 4 and group 5 adverbs.
4.2.2.
Correlation analysis
Similar to the hierarchical division, data were further analysed with a correlation analysis. For this purpose
proportion of sentences with a finite verb and an adverb was used as dependent variable and groups of
adverbs as independent variable. Given that the alternative division does not follow Cinque’s adverb
hierarchy, adverb groups do not correspond to one group of hierarchical functional heads. In fact,
alternative adverb groups supposedly include functional heads of all positions in the syntactic tree. Since
production of a finite verb is related to presence of or access to a higher functional head, it is expected
that no significant correlations between proportion of finite verbs and any adverb group will be observed.
Table 12 shows results of the correlation analysis:
Subjects
Broca’s aphasia
30
Correlating groups Correlation coefficient
Group 1
Positive
Group 2
- .726
Group 3
.528
Group 4
Positive
Group 5
Positive
Group 6
Positive
Unimpaired controls Group 1
Positive
Group 2
Negative
Group 3
Negative
Group 4
Negative
Group 5
Positive
Group 6
Negative
Wernicke’s aphasia Group 1
Negative
Group 2
- .572
Group 3
- .625
Group 4
.609
Group 5
.743
Group 6
Negative
Table 12: Results of the correlation analysis; alternative division.
30
31
31
Significance level
Non-significant
.009
Nearly sig (.059)
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
Non-significant
.042
.027
.031
.007
Non-significant
This coefficient represents Pearson’s correlation coefficient.
This significance level is obtained from a one-tailed test.
36
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Proportion of finite verbs in the Broca’s aphasic group is significantly negatively correlated with realisation
of group 2 adverbs; R = - .726, p < .05, meaning that presence of a group 2 adverb decreases the chance
of realising a finite verb. Consequently, chance of finding either an infinitive or no verb at all increases.
This negative correlation in group 2 was observed in the Wernicke’s aphasic group also; R = - .572. Group
3 adverbs correlate significantly negatively with proportion of finite verbs in Wernicke’s aphasics;
R = - .625, p < .05, which opposes the nearly significant positive correlation in Broca’s aphasia: R = .528,
p = .059. Group 4 and group 5 adverbs in Wernicke’s aphasia correlate positively with realisation of finite
verbs, respectively; R = .609 and R = .743, p < .05.
Similar to the hierarchical division, no significant correlation effects were found in the unimpaired groups in
the alternative division.
Although no correlation effect was expected in this alternative division, correlation effects occurred. The
prediction that no correlation in the alternative division would be found was based on the assumption that
the alternative division does not follow Cinque’s hierarchy. To explain presence of correlation effects,
proportions of hierarchical groups of adverbs within one alternative group were calculated.
ALTERNATIVE
PROPORTION GROUPS OF CINQUE’S HIERARCHY
GROUPS
Group 1
Group 2
Group 3
Group 4
Group 5
Group 1
58.13
41.87
Group 2
1.64
10.00
15.88
Group 3
6.56
1.90
15.73
38.05
28.55
Group 4
24.64
58.72
1.42
Group 5
100.00
Group 6
18.31
18.53
55.48
Table 13: Mean proportions of hierarchical adverb groups within one alternative group.
Group 6
72.48
9.25
15.22
7.67
Table 13 reveals that the assumption that the alternative division does not follow Cinque’s hierarchy is not
true. Especially group 1 and group 5 actually match Cinque’s hierarchy quite well. Although group 2
appears to not follow the hierarchy, the largest proportion is explained by hierarchical group 6.
4.3. Results of regression analyses
Regression analyses were performed to examine which division of adverbs best fitted the data. A
regression analysis builds a model from correlations between dependent (proportion finite verbs) and
independent variables (adverb groups). This model can be used to predict outcomes of the dependent
variable if values of independent variables are known. Regression analyses calculate a regression
coefficient, R, which expresses correlation between the dependent variable and all independent variables
together. The squared correlation coefficient, R2, tells which proportion of variance in the dependent
variable is explained by combined contributions of independent variables.
For regression analyses, proportion of finite verbs in all sentences with an adverb is used as dependent
variable and groups of adverbs as independent variables. Proportion of finite verbs indicates how many
syntactic trees have been built at least up to TP. If the TPH is correct, TP is inaccessible for Broca’s
aphasics. Therefore, production of finite verbs will be affected by tree pruning in Broca’s aphasia. The
hypothesized syntactic deficit should be reflected in the regression coefficient, since a syntactic deficit
affects both adverb production and finite verb production.
Two methods are used to explore which model best fits the data for every division (1) entering groups of
adverbs according to Cinque’s hierarchy and (2) entering data using a method where statistical software
selects the best order of entry for groups of adverbs; the ‘backward’ method. Order of data entry did not
affect regression coefficients. Table 14 on the next page shows regression coefficients:
37
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Analysis
Hierarchical groups
Group subjects
Broca’s aphasia
Unimpaired controls
Wernicke’s aphasia
Alternative groups
Broca’s aphasia
Unimpaired controls
Wernicke’s aphasia
Table 14: Results of regression analyses.
R
.789
.595
.909
.760
.638
.968
Femke Nouwens
R2
.622
.354
.827
.577
.407
.937
Table 14 shows that the hierarchical grouping best fits data from Broca’s aphasics, because 62.2% of
variance in the data is explained by the model. Differences between the hierarchical model and the
alternative model are not considerably large, because the alternative model explains 57.7% of the
variance. The model based on the alternative grouping of Cinque’s hierarchy explains the largest
proportion of variance in the proportion of finite verbs in unimpaired controls and Wernicke’s aphasics;
40.7% and 93.7%. However, the model of the hierarchical division fits data from unimpaired controls
almost as well as the alternative model; 35.4%.
Only little variance in production of finite verbs by Wernicke’s aphasics remains unexplained by the
alternative grouping; 6.3%.
The model based on the syntactic tree best explains data from Broca’s aphasics, but the model based on
semantic principles has almost equal explanatory power. A similar result is observed for unimpaired
controls, although the alternative model explained their data slightly better. The model based on semantic
principles best explains data from Wernicke’s aphasics.
38
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Chapter 5
Discussion
5.1. Grouping according to Cinque’s hierarchy
The goal of the present study was to test the Tree Pruning hypothesis for Broca’s aphasia. The TPH
claims that the higher region of the syntactic tree is pruned from Broca’s aphasics’ speech. Consequently,
adverb distribution in Broca’s aphasia depends on localization of adverbs in the syntactic tree. Cinque’s
universal adverb hierarchy (1999) is used to relate adverb types to a distinct position in the syntactic tree.
Combination of the TPH and Cinque’s hypothesis led to a number of predictions which were tested with
analyses of spontaneous speech samples.
Adverb distribution patterns were determined for every subject group. Adverb distribution patterns in
Figure 7 were quite similar for all subject groups. However, two patterns were distinguished (1) unimpaired
controls produced more adverbs from the highest four groups than Broca’s aphasics and (2) Broca’s
aphasics produced more adverbs from group 5 and group 6 than unimpaired controls. Wernicke’s
aphasics performed in between Broca’s aphasics and unimpaired controls.
The strictest version of the TPH predicts no high adverbs in Broca’s aphasia, because higher functional
heads supposedly are pruned and inaccessible. This claim is falsified by the present study, because in
contradiction to an absolute absence, Broca’s aphasics are capable of producing these ‘high’ adverbs. In
fact, the production pattern of these high adverb groups is similar in Broca’s aphasics and unimpaired
controls. The preference pattern for the lowest two adverb groups was different between subject groups.
Broca’s aphasics showed an increase, whereas unimpaired controls showed a nadir in group 5, after
which the pattern rises in group 6. Two different patterns between subject groups were observed; one
regarding the cluster of four highest adverb groups and one regarding the cluster of lowest two adverb
groups.
Preference for lower adverb groups in Broca’s aphasia could have been caused by a tree pruning
phenomenon. As a consequence of the suggested impairment of higher adverb groups, frequency of
39
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
adverb production corresponding to higher functional heads decreases, which causes a relative increase
of the lower two adverb groups.
Friedmann and Grodzinsky (1997) included a severity metric in their TPH. This severity metric implies that
the higher a functional head is located in the syntactic tree, the higher the chances that this functional
head is affected by tree pruning. This should be visible in the data as a gradual decrease of production of
adverb groups located higher in the syntactic tree. In fact, Alexiadou and Stavrakaki (2006) observed such
a pattern in the error pattern of one Broca’s aphasic subject. Their subject showed a gradually increasing
error pattern as adverbs were located higher in the syntactic tree.
Figure 5 in section §4.1 shows a pattern of gradual decrease of proportions of adverb groups in the
Broca’s aphasic group, if group 2 is disregarded for a moment. Lower adverb groups are less likely to be
pruned, thus relative frequency of low adverb groups grows at the cost of higher adverb groups. The
severity metric appears to be visible in the data.
Figure 5 shows that the decrease of adverb production in the Broca’s aphasic group is not gradual as
expected by the TPH plus severity metric. Group 2 adverbs stand out as very frequently used high
adverbs in Broca’s aphasia. This frequent use of group 2 is observed in unimpaired controls also. This
further supports the existence of similarities between Broca’s aphasic’s adverb distribution and unimpaired
adverb production as described above.
The TPH claims that higher functional categories are inaccessible because of pruning and assumes that
linguistic knowledge is damaged in Broca’s aphasia. Consequently, it is predicted that Broca’s aphasics
perform significantly different from unimpaired controls at least regarding high regions of the syntactic tree.
This is not confirmed by data from the present study, because similarities are observed between Broca’s
aphasics and unimpaired controls. The data confirm presence of a pruning effect in the Broca’s aphasic
group, because an effect causing higher adverb groups to be less frequently produced than lower adverb
groups was observed indeed.
To explain these findings a metaphorically ‘on/off switch’ for tree pruning is proposed. When the ‘switch’ is
on, higher nodes become inaccessible. This is reflected in the apparent preference for lower adverbs.
When the ‘tree pruning switch’ is off, Broca’s aphasics have access to the syntactic tree. Consequently,
they are able to use higher adverbs. When the ‘pruning switch’ is off Broca’s aphasics perform similar to
unimpaired controls.
Existence of an ‘on/off switch’ for tree pruning is confirmed by correlation analysis. Correlation showed
that realization of an adverb from group 6 is significantly negatively correlated with production of finite
verbs, thus finite verbs are omitted when group 6 adverbs are produced. In line with the TPH, it is
assumed that a finite verb can only be produced if the syntactic tree is built to at least the TP node.
Omission of a finite verb implies incomplete building of the syntactic tree. Consequently, omission of a
finite verb is related to tree pruning. Negative correlation of group 6 in Broca’s aphasia is explained when
the ‘switch’ for tree pruning is active, because then merely lower adverbs are produced. Consequences
and requirements for the existence of an ‘on/off switch’ for tree pruning are discussed more extensively in
the next chapter.
Adverb group 4 is significantly positively correlated with production of finite verbs in the Broca’s aphasic
group. This might be due to the types of adverbs included in this group. Group 4 includes: terminative
aspect (no longer), continuative aspect (still), perfect/imperfect aspect (always), retrospective aspect (just)
and proximative aspect (soon). These adverbs are semantically highly connected to presence of a finite
verb, illustrated by the following examples:
(35)
Ik vertelde hem een grap. Hij lachen.
(I told him a joke. He to laugh)
Ik vertelde hem een grap. * Hij niet meer/nog/altijd lachen.
(I told him a joke. * He no longer/still/always to laugh)
Ik vertelde hem een grap. Hij moet niet meer/nog/altijd/ lachen.
(I told him a joke. He must no longer/still/always laugh)
Ik vertelde hem een grap. * Hij niet meer/nog/altijd vrolijk.
(I told him a joke. * He no longer/still/always happy)
40
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Examples in (35) show that use of adverbs from group 4 without an inflected verb nearly always results in
an ungrammatical sentence. High correlation of group 4 and finite verbs is probably caused by this
semantic phenomenon. Adverb distribution of unimpaired controls shows that group 4 adverbs are very
popular. This implies that if the language production system is intact, people32 produce finite verbs nearly
always and relatively more adverbs from group 4 than other adverb groups (apart from the more popular
group 2 adverbs). Even though group 4 adverbs receive average popularity in adverb distribution of
Broca’s aphasics, significant correlation with finite verbs implies that when the pruning phenomenon is not
active, Broca’s aphasics behave similar to unimpaired controls and prefer group 4 adverbs.
Avrutin’s Weak Syntax Hypothesis (2006) is proposed to explain the existence of a switch that either does
or does not trigger the tree pruning phenomenon. The Weak Syntax hypothesis predicts a 50/50 chance
for victory of either the narrow syntax system or the discourse system. If the switch is ‘on’ discourse won
the “competition” and narrow syntax won if the switch is “off”.
Results from this study suggest two possible locations for the pruning phenomenon. When Figure 7 is
examined, it is observed that adverb distribution patterns are no longer similar regarding production of
group 5 and group 6 adverbs. It is suggested that relative high preference of low adverb groups in Broca’s
aphasia is related to a tree pruning effect. The observation that Broca’s aphasics produce group 5 and
group 6 adverbs relatively more than unimpaired controls suggests that the pruning phenomenon is
inactive from group 5 downwards. Adverb groups from group 4 upwards are produced less by Broca’s
aphasics compared to unimpaired controls. Consequently, it seems plausible to locate the pruning location
above group 5.
However, correlation analysis provides some counterevidence. If the pruning was located above group 5,
it is expected that when the ‘pruning switch’ is on, production of finite verbs decreases due to
inaccessibility of TP. No such negative correlation was observed for group 5 in Broca’s aphasics. In fact,
group 5 is positively correlated with the proportion of finite verbs. Consequently, it is not likely that the
pruning ‘switch’ is located above group 5. This suggests that if the pruning phenomenon is active it affects
all functional heads above the functional heads that are specified by group 6 adverbs.
Results do not provide conclusive evidence for either pruning location. Additional analyses are necessary
to determine the exact location of the pruning phenomenon. This is however outside the scope of the
present study.
Wernicke’s aphasics are expected to perform differently from Broca’s aphasics given the considerable
differences between these aphasia syndromes. When we look at Wernicke’s aphasics in Figure 7, we see
that this group performs in between the other two subject groups regarding all adverb groups. Also,
adverb distribution patterns are similar. Consequently, the expectation of significant differences between
Wernicke’s and Broca’s aphasics with respect to adverb use seems falsified. Resemblances of adverb
distributions imply two things: (1) adverb distribution in Wernicke’s aphasia is not as pronounced as
adverb distributions in the other two subject groups, implying that Wernicke’s aphasics have less strong
preferences for groups of adverbs and (2) it appears that Wernicke’s aphasics have a similar deficit as
Broca’s aphasics, but not as severe.
Although the present study was not meant to explain the underlying deficit in Wernicke’s aphasia a
suggestion is proposed. In the absence of extensive research on Wernicke’s aphasia and present results
not matching the predictions, only speculation on what might be impaired in Wernicke’s aphasia is
possible.
In line with limited previous studies on Wernicke’s aphasia it is suggested that narrow syntax functions
properly regarding higher nodes in Wernicke’s aphasia. Similarities between Broca’s and Wernicke’s
aphasics indicate that adverbs corresponding to the higher syntactic nodes were fewer realised compared
to unimpaired production. A deficit in the lexical activation system is proposed to explain this pattern in
Wernicke’s aphasia, in line with Swinney and Zurif (1995). They suggested that syntactic and semantic
processes are disconnected in Wernicke’s aphasia; syntactic processes are correctly performed
regardless of incorrect semantic components.
Kempen and Harbusch (2002) claim that sentence processing consists of two processes; a syntactic
hierarchy building process and a lexical activation process. It is proposed that a proper functioning narrow
syntax system provides Wernicke’s aphasics with a complete syntactic tree. Assuming that VP is not
affected by aphasia, this node is completely built and the lexical activation system correctly activates
32
The word “people” is used here although it is not claimed that the present study can be generalised. More data has to be analysed
first.
41
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
corresponding word types, among which low adverbs. Wernicke’s aphasia might be explained by a
malfunctioning lexical activation system regarding higher functional heads. Malfunctions can be
characterized as the inability to activate words corresponding to the conceptual idea. Instead, the lexical
activation system randomly activates word strings matching the hierarchy of functional heads, but not
agree with respect to their meaning. This phenomenon might explain the paragrammatisms discussed in
section §2.1.2 and matches experiences with Wernicke’s aphasics’ language. Usually, Wernicke’s
aphasics’ speech is characterized by word strings that seem grammatical with an intact prosody, but turn
out to be meaningless.
A hypothesis in the line of Avrutin’s Weak Syntax hypothesis could be suggested also. Brain damage in
both Broca’s and Wernicke’s aphasia causes a weakening of narrow syntax, because processing
capacities are limited. In Broca’s aphasics the system is more severely damaged than in Wernicke’s
aphasics. Narrow syntax thus has less chances of winning the competition with discourse in Broca’s
aphasia, whereas these chances are higher in Wernicke’s aphasia. Personal experience in treating
Wernicke’s aphasics informs that these aphasics do not perform similar to Broca’s aphasics and
unimpaired controls. Fluently produced paragrammatisms do not resemble unimpaired speech and
certainly not the effortful speech of Broca’s aphasics.
Similarities between Broca’s and Wernicke’s aphasics might be due to the initial classification by means of
the AATP. The AATP provides measures for the degree of aphasic behaviour and matches results to one
of the four major aphasia syndromes; Global, Broca’s, Wernicke’s and Amnestic aphasia. Consequently,
subjects may have been classified as Wernicke’s aphasic, whereas they show moderate Broca’s aphasic
behaviour also and vice versa.
5.2. Grouping according to an alternative approach
Six alternative groups were used for examination whether a semantic grouping of adverbs from Cinque’s
hierarchy reveals different results than the hierarchical grouping. These groups were based on
Jackendoff’s and Nilsen’s vision on adverb classification. The groups are repeated below:
Group 1: based on an adjective and combines with ‘-erwijs/-wijs/-gewijs’
Group 2: based on an adjective and questionable with ‘how’
Group 3: ‘temporal’, always interpretable
Group 4: ‘temporal’, with accommodation interpretable
Group 5: ‘temporal’, impossibly interpretable without context
Group 6: non-adjective/non-temporal
Group 6 is disregarded in the discussion, because this group is negatively formulated (non-adjective and
non-temporal) and no clear conclusions can be based on this group.
The alternative division is not based on syntactic principles. Since Broca’s aphasia is related to syntactic
impairment, predictions on one hierarchy in six alternative groups could not be formulated. However, two
sub-hierarchies were hypothesized.
Group 1 and group 2 both consisted of adverbs that are based on an adjective. Group 1 was distinguished
from group 2 since only highest adverbs from Cinque’s hierarchy were included. Group 2 consisted of
adverbs from the remaining lower region of the hierarchy. Table 13 showed that alternative group 1
consisted of hierarchical group 1 and 2 adverbs, whereas alternative group 2 consisted mainly of
hierarchical group 6 adverbs. If the TPH is correct, alternative group 1 adverbs should be less frequently
produced than alternative group 2. This was confirmed by data from the present study, because Broca’s
aphasics clearly preferred group 2 adverbs over group 1 adverbs.
A hierarchy in Broca’s aphasics was also hypothesized regarding temporal groups of adverbs. This
hypothesis was based on differences of discourse dependency between adverb groups. When unimpaired
controls’ adverb distribution was examined in Figure 10 and 12, we saw that group 5 adverbs were
preferred, followed by group 4. Group 3 adverbs were relatively least popular. Wernicke’s aphasics and
Broca’s aphasics did not show this explicit preference for group 5 adverbs. Instead, group 4 was most
preferred in these subjects. In the hypothesized hierarchy in temporal adverbs, group 3 adverbs would be
42
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
preferred most, followed by group 4 and group 5 would be least preferred. An opposite pattern was
observed in the data, which falsifies the hypothesis of a hierarchy in the temporal adverb groups based on
discourse dependencies and reference requirements.
In unimpaired controls group 5 adverbs were most popular, which was confirmed by post hoc analysis.
These adverbs depend on discourse information and require correct reference operations. Consequently,
a combination of narrow syntax operations and discourse operations is necessary. Broca’s aphasics do
not show a clear preference for this adverb group. In fact, this adverb group was located in between group
2 on the one hand and group 1 and 3 on the other hand in a preference hierarchy. An adverb group that
depends on narrow syntax operations and discourse operations is produced in between groups of adverbs
either depending on narrow syntax; group 1 and 3, or on discourse; group 2. This further supports the
existence of a metaphorically ‘on/off switch’ for pruning, causing an approximately 50/50 division of narrow
syntax related adverbs and discourse system related adverbs.
Distribution patterns of Wernicke’s aphasics and Broca’s aphasics showed similarities regarding the three
temporal adverb groups, but Wernicke’s aphasics produced these adverb groups relatively more than
Broca’s aphasics. Table 13 revealed that temporal adverb groups consisted of hierarchical adverb groups
located above the pruning location. This difference in temporal adverbs between Broca’s and Wernicke’s
aphasics implies differences in severity of impairments. This observation was reinforced by the relative
popularity of group 1 adverbs in Wernicke’s aphasics which was not observed in Broca’s aphasics. This
implies that functional heads corresponding to the highest two hierarchical adverb groups are better
accessible to Wernicke’s aphasics than Broca’s aphasics.
Remarkably, Wernicke’s aphasics perform different from unimpaired controls on all groups of adverbs,
because for every adverb group a crossing of the adverb distribution lines was observed in Figure 12. This
distinction between unimpaired controls and Wernicke’s aphasics’ adverb distribution is revealed by a
semantic division of adverbs. Therefore, a syntactic deficit as well as a semantic deficit is suggested for
Wernicke’s aphasia. This explains disturbances observed in communication with Wernicke’s aphasics,
because semantic deficits are more dominant than syntactic deficits in speech samples. Correlation and
regression analyses are discussed first. Hereafter suggestions will be made what the data from the
present study can reveal about the deficit(s) in Wernicke’s aphasia.
Correlation coefficients in Table 12 revealed correlation between semantically defined adverb groups and
syntactically defined finite verb production. Consequently, a significant correlation can not be interpreted
as a semantic deficit. Hence, this alternative division will be used to explain the pruning effect in the
hierarchical division.
It is assumed that sentences with finite verb omission will be produced while the tree pruning phenomenon
is active. Significant negative correlation of group 2 with production of finite verbs in Broca’s aphasics
implies that pruning is active in group 2 adverbs. However, alternative group 2 mainly consisted of
hierarchical group 6 adverbs. This correlation confirms existence of a pruning effect occurring above
hierarchical group 6.
Group 3 is nearly significantly positively correlated (R = .528, p = .059) with finite verb production in
Broca’s aphasics. Alternative group 3 includes adverbs from the highest five hierarchical adverb groups,
but mostly consists of hierarchical group 4 and 5. Nearly 30% of the proportion in alternative group 3
stems from hierarchical group 5. The positive correlation of finite verb production with these higher adverb
groups implies that the pruning phenomenon is not present.
No significant correlations between groups of adverbs and production of finite verbs were found in the
unimpaired group. This was expected, because the hierarchical division showed that adverb distribution is
not connected to verb production and vice versa, if the language system is intact.
Group 2 and group 3 correlated negatively with production of finite verbs in Wernicke’s aphasics. Group 2
and group 3 in the alternative grouping consisted most of the two lowest hierarchical groups. Group 4 and
group 5 correlated positively with production of finite verbs and corresponded to hierarchical group 2 and
4, i.e. to higher functional heads. Although these results can be used to explain a syntactic difference, this
does not match observations of Wernicke’s aphasic speech. An example from a Wernicke’s aphasic
subject in the corpus is presented below to illustrate why the assumption that Wernicke’s aphasia is
restricted to either a semantic or syntactic deficit is probably incorrect:
43
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Asp_terminative
Subject: En (uh) de laatste tijd nou geen last meer
Femke Nouwens
33
gehad/30 .
(and uhm the last time well no problem anymore had)
Subject: Nee (nou) heel gezellig via die mensen gezellig met mensen/31.
(no well very pleasantly via those people pleasantly with people)
Subject: Nou nog een beetje kunnen heel ‘soenlijk (=fatsoenlijk?) daar maar kunnen rijden
eigenlijk mood_speech act/32.
(well yet a bit to may very (paraphasia, probably: decently) there but can drive actually)
AspPl_completive
Subject: (Ja) is een beetje (uh beetje uh) voelig (=gevoelig?) allemaal
(ja)/33
(yes is a bit uh bit uh (paraphasia, probably: sensitive) all)
Speech therapist: Een beetje gevoelig?
(a bit sensitive?)
Subject: (Oh) nee hoor (nee) ik vond het echt wel leuk
Voice
/34.
(oh no oh no I found it truly rather nice)
Subject: (Nee hallo) ‘t was heel gewoon/35
(no hello it was very ordinary)
Subject: (uh) zeg nou zo kan je naar een bedje thuis komt/36
(uh say well this way could you to a small bed at home comes)
This fragment of spontaneous speech reveals that there are both semantic deficits and syntactic deficits.
An examination of the content of this fragment reveals that this fragment is nearly meaningless. The
answer to the question is completely irrelevant also. This implies a deficit in the semantic system.
Syntactic errors are observed in sentences 32 and 36. However, this subject was capable of producing
grammatical sentences such as 34 and 35.
Correlation analyses can be interpreted as being effects of a syntactic deficit, but the fragment above
shows that further research is necessary on deficits in Wernicke’s aphasia. Error analyses, for instance,
should provide more insight in impairments of Wernicke’s aphasia.
5.3. Regression analyses
Given that tree pruning is a deficit of the syntactic system, it is expected that, at least in Broca’s aphasics,
the hierarchical model explains most of variance in production of a syntactic process; finite verb
production. Regression analysis of Broca’s aphasics’ data confirmed this, although the alternative model
explained variance almost equally well. This was observed in unimpaired controls also. Even though this
was not expected, it further supports the observation that Broca’s aphasics perform almost similar to
unimpaired controls with respect to adverb use.
Variance is better explained in Broca’s aphasics than in unimpaired controls. This can be explained by the
tree pruning phenomenon which affects both verb and adverb production. In unimpaired controls, no
pruning phenomenon is active. Therefore, adverb distribution and verb production do not correspond
considerably in this subject group.
If we look at the two regression coefficients in the Wernicke’s aphasic group we see a difference of 11%
between the hierarchical and the alternative grouping. The alternative grouping best explains variance in
production of sentences with an adverb and a finite verb. Remarkably, both divisions explain a large
proportion of variance in the dependent variable. This suggests that both a semantic and a syntactic
division explain variance in a narrow syntax operation quite well.
To clarify deficits in Wernicke’s aphasia variability in a syntactic operation (verb inflection) should be
explained by a semantic division of adverbs. Given that no such relationship exists in the unimpaired
group, this relationship between adverbs and finite verbs should be revealed in Wernicke’s aphasia.
33
This numbering comes from the actual speech sample; therefore numbers are sentence final.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
However, semantic processes were not examined elaborately. Therefore, data of the present study do not
contribute to explanation of this observation.
Adverb distribution of Wernicke’s aphasics in the hierarchical division revealed deviations from the
unimpaired group attributed to a syntactic deficit. However, the alternative division reveals deviations from
unimpaired language regarding semantic processes. This implies a combined deficit of both the semantic
and the syntactic system. Such a deficit characterises descriptions of Wernicke’s aphasia well. The
following sentences produced by subjects in the Wernicke’s aphasic group are examples of such a
combined deficit:
(36)
Ja niet met die hand omdat ik er niet bij toe allemaalAspPl_completive ineensAsp_celerative(I) overal
heen/.
(yes not with that hand because I there not at towards all suddenly everywhere to)
(37)
Naar gelang dan een keer het naar eeringsweten is van gebracht af nagenoegAspSg_completive(II).
(analogous then for one time it to (neologism) is of brought of nearly)
(38)
Dat wist ik dan
T(past)
niet voor de mensen om te komen was altijd
Asp_perfective
zo zouden moeten
horen.
(that knew I then not for the people to come was always like this should must to hear)
In example (36) the verb is omitted and has an awkward meaning. The sentence final adverb “nagenoeg”
in (37) is located incorrectly and word order is incorrect. Example (38) seems to be formed by stacking
incomplete phrases. The following phrases can be distinguished [dat wist ik dan niet voor de mensen] [om
te komen was altijd] [zo zouden moeten horen]. The sentences above are examples of jargon; a sequence
of words without a clear meaning.
Although an attempt was made to explain Wernicke’s aphasics’ behaviour with results from this study,
results do not contribute considerably to explanation of Wernicke’s aphasia, because error patterns were
not analysed. Error patterns might reveal significant differences between Wernicke’s aphasics and Broca’s
aphasics and unimpaired controls. By performing error analyses paragrammatism will become visible.
Consequently, a hypothesis such as a malfunctioning lexical activation system or a combined semantic
and syntactic deficit as proposed in the previous sections might be tested.
5.4. Summary of the results in relation to the research questions and predictions
This chapter is completed with a summary of the predictions that could be verified by the results of the
present study.
I
Is Cinque’s adverb hierarchy compatible with the Tree Pruning Hypothesis?
A preference for low adverbs in Broca’s aphasics is verified. It is predicted also that the TPH combined
with severity metric will reveal a gradual decrease in preference for adverb groups as they are located
higher in the syntactic tree in Broca’s aphasics. This was partly verified, because the penultimate highest
adverb group is relatively preferred by Broca’s aphasics. However, this preference resembled unimpaired
production.
The third expectation that significant differences should exist between Broca’s aphasics and two control
groups regarding high adverbs is falsified. In fact, all subject groups revealed a similar pattern regarding
preference for the highest four adverb groups. The patterns differed regarding lowest two adverb groups.
This difference coheres with the pruning phenomenon. The present study indicates two possible pruning
locations; either above group 5 or above group 6.
The final prediction is verified by this study, but not as expected. High groups of adverbs were expected to
correlate with finite verb production in the Broca’s aphasic group. However, presence of low adverb
groups correlated significantly negatively with production of sentences with a finite verb and an adverb, i.e.
with omission of a finite verb. Higher adverbs did not correlate significantly with verb types and was similar
to observations in unimpaired controls. One group of adverbs was significantly positively correlated with
45
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
finite verb production. This was explained by a semantic restriction that requires a finite verb in
combination with these adverbs.
Analysis of the hierarchical division of Cinque’s adverb hierarchy leads to the conclusion that adverb
distribution in Broca’s aphasia is compatible with phenomena described by the TPH. However, Friedmann
and Grodzinsky’s versions of the TPH are not sufficiently able to explain data from the present study.
Therefore, an alternative version of the TPH combined with the more psycholinguistic hypothesis by
Avrutin is proposed. In the following chapter conditions for such a hypothesis are discussed.
II
Is the alternative division of Cinque’s adverb hierarchy compatible with the Tree Pruning
hypothesis?
Firstly, no significant differences were predicted between alternative adverb groups in the Broca’s aphasic
subjects. This hypothesis is falsified, since large differences between alternative adverb groups were
observed. These differences are attributed to interference of the hierarchical division. Alternative group 2
adverbs were most popular in Broca’s aphasics. This group consisted mainly of hierarchical group 6
adverbs. The pruning effect of the hierarchical grouping is responsible for relative popularity of alternative
group 2 adverbs.
Secondly, significant differences between Broca’s aphasics and two control groups were hypothesized in
this alternative division. The hypothesized differences point towards an underlying deficit different from the
deficit suggested by the TPH. The present study showed that all subject groups performed differently on
this alternative grouping. Most of these differences were explained by the fact that the alternative grouping
did not cross the syntactic tree as well as expected. Most differences contribute to the proposal of a
refined TPH.
III
Is a hierarchy observed within the alternative classification?
The predicted distinction between group 1 and group 2 is verified. Differently from the other subject
groups, Broca’s aphasics significantly preferred group 2 over group 1. This implies, in line with the TPH,
that higher syntactic nodes are impaired.
The following hierarchy regarding the temporal groups in Broca’s aphasics was predicted: group 5 less
preferred than group 4 and group 4 less preferred than group 3. This was not confirmed by results of the
present study. In fact, the following hierarchy was observed: group 3 and group 5 less preferred than
group 4. The expected ‘degree of difficulty hierarchy’ is falsified.
Significant differences were expected between subject groups regarding temporal adverb groups.
Distribution patterns of Broca’s aphasics and Wernicke’s aphasics showed great resemblances, but
patterns of unimpaired controls and Broca’s aphasics were completely opposite.
IV
Which regression model will fit the data best; a model based on the hierarchical classification
or a model based on the alternative classification?
If a model based on Cinque’s adverb hierarchy fits the data from Broca’s aphasics best, the underlying
deficit will have consequences for syntactic processes. However, if the alternative classification model fits
the data from Broca’s aphasics best the underlying deficit will have effects on semantic processes.
The model based on Cinque’s hierarchy fits Broca’s aphasics’ data best. A syntactic hypothesis for
explanation of the impairment in Broca’s aphasia thus seems most plausible. However, the alternative
model fits the data almost as well. This similarity was observed for unimpaired controls also, but
regression coefficients were smaller. This implies that Broca’s aphasics perform equal to unimpaired
controls, but have a syntactic deficit affecting adverb distribution and verb inflection. This can be explained
by the TPH with a metaphorical ‘on/off switch’, outlined in the next chapter.
Both regression models fitted the data from Wernicke’s aphasics quite well. The alternative model fitted
these data best. Regression analyses of Wernicke’s aphasics combined with other results from the
present study imply a combined deficit in Wernicke’s aphasia of both syntactic and semantic processes.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Chapter 6
General discussion and
conclusion
6.1. Discussion and recommendations for further research
Several limitations of this study will be discussed. One limitation is the number of participants34. It was not
possible in the limited time frame of this study to canvass more subjects. Nevertheless, this study is
valuable, because it is one of the few studies researching this topic. This study can be used as an
exploration of potential patterns of adverb distribution in aphasia combined with Cinque’s syntactic theory
of adverbs. The present proposal for a revision of the Tree Pruning Hypothesis should be supported by
further evidence collected in larger populations.
Considerable individual variation of quantities of adverbs was observed in spontaneous speech between
subject groups. This problem was solved using relative data to ensure that Broca’s aphasics could be
compared to unimpaired controls.
Variation between subject groups was observed within subject groups as well and may be attributed to the
collected data. Although interviews were semi-standardized35, subjects were not limited in their language
use. Consequently, data clearly reflect the free speech of the subjects.
Even if a language system is not impaired particular structures and words are preferred and even stronger
preferences may arise if a language system is damaged. Spontaneous speech is a good means to
measure these existing preferences. Nevertheless, spontaneous speech is less appropriate for detecting
34
Most statistical handbooks advise using sample sizes over 30 participants. Field (2005) claims a sample size of at least 28
participants is necessary if is set at .05, power = .8 and the desired effect size is large, r > .50 (Field; 2005, pp. 34).
35
Interviews were semi-standardized because the same topics were discussed in all interviews.
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
impaired language, because spontaneous language only provides positive evidence. For instance, if word
types or syntactic operations are not observed during spontaneous speech, this does not necessarily
imply that these word types or operations are impaired and can not be used.
This limitation of spontaneous speech does not play an important role in the present study, because an
unimpaired control group is analysed also. Consequently, control data are available about preferences in
an intact language system. This pattern of preferences can be compared to preferences of subjects with
an impaired language system. Preferences reflect which language competences are best retained. Further
research with experiments rather than spontaneous speech is recommended to determine which
competences are intact and which are damaged and to what degree. Constituent ordering tasks with
adverbs or more standardized production tasks could be suitable.
In addition to data from production tasks, it is important to gain comprehension data also. For instance, if a
high proportion of comprehension errors is observed in certain adverb types that are never observed in
spontaneous speech, this lack in production data might be attributed to comprehension deficits.
Focus of the present study is on adverbs that appear in Cinque’s universal adverb hierarchy. During initial
analyses all adverbs were selected in the samples. It turned out that a selection using Cinque’s hierarchy
selected only a fraction of adverbs that were produced. Use of Cinque’s hierarchy required a syntactic
approach to adverb distribution. More studies should be performed using other approaches to adverb
distribution, such as semantic and pragmatic approaches. During the search for an adverb theory,
compatible with a syntactic approach to adverb distribution, many linguistic classifications of adverbs
became apparent. This array of different approaches to adverb distribution and the variable use of
adverbs are suitable to investigate linguistic systems separately. More studies on adverb distribution on
different linguistic levels may attribute to objectifying exact deficits in aphasia.
In addition, it is important to investigate error patterns in adverb production, especially in Wernicke’s
aphasia, but Broca’s aphasics might use certain types of adverbs erroneously also. Prior to such studies
error patterns in unimpaired controls should be determined. Only if unimpaired data are present for
comparison deficits in aphasic speech can be truly established.
6.2. Conclusion from the results
Results using the hierarchical division of Cinque’s adverb hierarchy show that in Broca’s aphasics’
spontaneous speech low adverb groups are significantly preferred over higher adverb groups. Production
of the cluster of highest adverb groups showed much resemblance to production in unimpaired controls.
Consequently, a pattern becomes clear in which Broca’s aphasics perform similar to unimpaired controls
regarding higher adverbs, although low adverbs are preferred. The latter preference deviates from
unimpaired language production.
Distinct preference for lower adverb groups arises, because adverbs corresponding to higher functional
heads are impaired as suggested by the Tree Pruning Hypothesis, because the TPH claims that the high
region of the syntactic tree becomes inaccessible.
Regression analyses revealed a distinct difference between Wernicke’s aphasics and the two other
subject groups. Broca’s aphasics’ data explain variance in finite verb production equal to unimpaired
controls, but the relation between adverb groups and finite verb production is affected by a syntactic
deficit.
The TPH predicts an impairment of functional heads and corresponding adverbs of nodes high in the
syntactic tree. As a consequence, the TPH predicts differences in adverb distribution between Broca’s
aphasics and unimpaired controls. The present study does not confirm this prediction. Instead, a refined
version of the TPH is proposed to explain presence of high adverbs and similarities with unimpaired
production. For this purpose, Avrutin’s psycholinguistic theory (2006) is used.
6.3. Proposal for a refined theory of the deficit in Broca’s aphasia
This study confirms the foundations of the Tree Pruning Hypothesis, but is not completely compatible with
the TPH. Instead of a complete lack in production higher adverbs, a pattern of adverb distribution was
observed in Broca’s aphasics bearing a close resemblance to unimpaired adverb distribution. Broca’s
48
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
aphasics produced high adverb less often than unimpaired controls. Consequently, the proportion of
produced low adverbs increased.
To explain this pattern, a metaphorically ‘on/off switch’ for tree pruning is proposed based on Avrutin’s
Weak Syntax hypothesis (2006). Avrutin claims that brain damage in Broca’s area leads to a weakened
narrow syntax. Usually, narrow syntax is the most economical system for language production.
Information is generally encoded by narrow syntax operations, such as verb inflection and reference. If in
Broca’s aphasia narrow syntax is weakened, it becomes equally economical as the alternative information
encoding system: discourse. Discourse is used by unimpaired controls combined with a special register
and is used rather infrequently. As a consequence of a weaker narrow syntax, this system has to compete
with discourse, resulting in a 50/50 chance for both systems to be used to encode information.
If the ‘pruning switch’ is on, the syntactic tree is pruned from VP or the pruning location upwards.
Consequently, only nodes of the syntactic tree below the pruning location are accessible. Syntactic
processes above the pruning location are inaccessible resulting in agrammatic or telegraphic speech. If
the ‘pruning switch’ is off, the syntactic tree is available and completely grammatical sentences can be
produced as in unimpaired controls.
6.4. Requirements for the refined theory
For the refined theory to be accepted as a plausible explanation of Broca’s aphasia, several questions still
have to be answered.
The pruning location could not be determined exactly with the data. Possible pruning locations are
suggested to be situated above hierarchical group 5 or above group 6. The exact pruning location should
be determined.
The pruning location should separate functional heads affected by the impairment from preserved
functional heads. Word order, for instance, is affected by tree pruning. The basic template for a Dutch
sentence is SOV. Several Broca’s aphasics were observed who produced telegraphic speech, but they
were capable of realising subjects, objects and verbs, although uninflected. If the proposed hypothesis is
correct, telegraphic speech is produced when the ‘tree pruning ‘switch is on. However, the subjects were
capable of producing the basic template, VP. VP can be regarded as the core of a sentence. The pruning
location should therefore be located above the first functional head not regarded as part of the core of a
sentence.
The refined theory should be supported by a theory on sentence production. Several parsing studies have
claimed that during comprehension humans parse sentences from the bottom of the syntactic tree
upwards. However, on sentence production few theories are available. Kempen and Harbusch (2002)
describe their Performance Grammar, consisting of two processes; a lexical activation process and a
hierarchical tree building process. When this theory is combined with the proposal, the hierarchical tree
building process is regarded as a process of narrow syntax. The lexical activation process is regarded as
a process that precedes narrow syntax processes and feeds information chunks into the narrow syntax
system. Narrow syntax performs all necessary processes to produce a completely grammatical sentence.
When discourse wins the competition, i.e. if the ‘pruning switch’ is on, only information from the lexical
activation process is available; VP. Since VP is intact a functional head is available for specifying VP
adverb(s).
To explain the clear distinction between low adverb groups and the cluster of high adverb groups a
production theory should include sentences being built from a basic template upwards. This basic
template could be the cluster of functional heads from the pruning location downwards. A production
theory has to account for a distinction between higher syntactic nodes and a specific cluster of low nodes
at which the competition between narrow syntax and discourse is visible.
Given that a proper production theory is yet not formulated, only speculations are possible as to which
processes are activated to implement knowledge of the damaged language system.
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Femke Nouwens
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Appendices
Femke Nouwens
Page
Appendix I: Explanation of functional heads in Cinque’s hierarchy
1
Appendix II: Tense in the neo-Reichenbach tense-system
5
Appendix III: Tables of raw data; division in hierarchical groups
6
Appendix IV: Tables of relative data; division in hierarchical groups
7
Appendix V: Tables of raw data; alternative division
8
Appendix VI: Tables of relative data; alternative division
9
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Appendix I: Explanation of functional heads in Cinque’s hierarchy
1. Speech act mood
Speech act adverbs are licensed under speech act mood. Speech act mood provides information about
the way a sentence in uttered. Although there are exceptions, most languages distinguish declarative,
interrogative and imperative mood. Speech act adverbs are also capable of qualifying the speaker’s act of
assertion, for example: frankly, honestly and sincerely (Cinque, 1999).
2. Evaluative mood
Evaluative mood expresses the speaker’s evaluation of the event that is described. This mood can be
expressed with affixes (for instance in Korean and in Australian Ngiyambaa) and with free morphemes,
such as adverbs. With evaluative mood approval, disapproval, failure, surprise, disappointment etc. are
expressed. Adverbs such as: (un)fortunately, luckily, regrettably, surprisingly, strangely, oddly (enough),
(un)expectedly, etc. (Cinque, 1999) are found in specifier position of evaluative mood.
3. Evidential mood
A speaker expresses evidence he possesses for his declaration through evidential mood. There are
differences across languages in ways evidence can be presented. Some languages distinguish between
auditory, visual and sensory evidence via evidential affixes, modals, periphrases or particles. English
examples of evidential adverbs are: allegedly (only evidence from hearsay), reportedly (evidence from
what people say), apparently (the speaker regards the declaration as proven), obviously (no doubt about it
that it is true), clearly (proof exists) and evidently (proof exists) etc. (Cinque, 1999).
4. Epistemic modality
Epistemic modality expresses degree of confidence the speaker has towards truth of the proposition.
Confidence is based on evidence the speaker possesses. Therefore, epistemic modality is related to
evidential mood. Epistemic mood can be expressed with speaker orientated adverbs, such as probably,
likely, presumably, supposedly, etc. (Cinque, 1999).
5. Tense
From epistemic mood downwards in the syntactic tree TP is reached consisting of T(past) and T(future).
Adverbs specifying these functional heads are strictly deictic temporal adverbs such as: then, once, etc.
Remaining, more obviously, temporal adverbs such as: tomorrow, yesterday, today etc. (Cinque, 1999)
can not surface in IP-domain. Instead, they are placed sentence initially or finally according to Cinque.
Cinque classifies these adverbs as ‘adverbs of setting’ or ‘circumstantial adverbs’.
6. Irrealis mood
Cinque classifies the English adverb ‘perhaps’ as a specifier of irrealis mood. Irrealis mood expresses
events of which it is not ascertained whether they happened or not, like desires, wishes and necessities.
Cinque states that Dutch adverbs “waarschijnlijk” (probably) and “misschien” (perhaps) behave similarly.
Although it appears that these adverbs behave like epistemic adverbs, their distribution in a sentence
differs across languages. Cinque concludes that “perhaps”, “waarschijnlijk” and “misschien” are specifiers
of a separate functional head: irrealis mood.
7. Alethic modality
‘Necessarily’ and ‘possibly’ are adverbs appearing in specifier position of alethic modality. With alethic
modality, a speaker’s estimation of necessity or possibility of the proposition is expressed. Examples from
different languages place this modality in necessity modality, in between epistemic and root modality.
8. Habitual aspect
Habitual adverbs correspond to the functional head: habitual aspect. Comrie (1976; in: Cinque, 1999)
defines habitual aspect as: “describing a situation which is characteristic of an extended period of time”.
Habitual events occur during a certain period of time. Habitual aspect is different from iterative and
frequentative aspect, because the latter refers to repetition of an event, not to an event occurring
customary. Habitual aspect may be expressed through habitual adverbs, such as: usually, habitually,
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Femke Nouwens
customarily, generally, regularly, etc. (Cinque, 1999). Not only adverbs can be used to express habitual
aspect, temporal NP’s or a periphrase like “use(d) to...” are possible also:
(1)
Every Sunday we visited our grannies
Habitual aspect by means of a temporal NP
On Sundays we used to visit our grannies
Habitual aspect by means of a periphrase
Regularly we visited our grannies on Sunday
Habitual aspect by means of a habitual adverb
Habitual aspect is highest in line of aspectual heads in the syntactic structure.
9. Repetitive/frequentative aspect
Repetitive and frequentative functional head are often used synonymously. The term iterative might be
used also. It is difficult to discover agreement cross-linguistically. Some languages express repetition
frequency by adding affixes to the verb and other languages express this aspect via adverbs.
A frequentative adverb may quantify over the event in which a certain process is involved and they may
quantify over the process alone. These two distinctions correspond to two locations in a sentence;
(2)
Gianni, saggiamente, spesso esce con la stessa persona spesso.
(Gianni, wisely, often dates the same person often.)
(from: Cinque, 1999)
Example (2) shows two locations of the Italian frequentative adverb “spesso”. The first “spesso” quantifies
over ‘dating same persons often’ and the second “spesso” quantifies over ‘dating same persons’.
This high and low location of the frequentative adverb is found in many languages. Location of both higher
and lower versions seems to be fixed with respect to the surrounding adverbs. Therefore, Cinque
concludes that these two locations are not caused by movement of one adverb, but instead originate from
existence of two functional heads where the adverb can attach. Consequently, Cinque reserved two
locations in his hierarchy for frequentative adverbs: Aspect frequentative(I) and Aspect frequentative(II). The same
phenomenon was observed for repetitive adverbs. Cinque distinguishes between Aspect repetitive(I) and
Aspect repetitive(II).This is illustrated by the following examples:
(3)
When we wanted to talk quietly, he entered the room again
(4)
After staying out all night, the cat finally came in again
repetition of the entire event
repetition of the ‘being in’ state
In the first example ‘again’ has scope over the entire event of entering a room, i.e. opening a door,
stepping over the doorstep and physically being present in the room. ‘Again’ in the second example has
scope over the state of being indoors.
10. Celerative aspect
Adverbs that qualify speed of an event are licensed as specifiers of celerative aspect. These adverbs may
quantify over the event and have a subject-orientated reading. They may also quantify over the verb and
have a manner reading;
(5)
When he was asked to leave, John quickly left the building.
(6)
When the fire broke loose, John left the building quickly.
In (5) ‘quickly’ quantifies over the event of ‘leaving a building’. When John was asked to leave the building,
he did it quickly after the request; he did not wait for half an hour. In (6) however ‘quickly’ quantifies over
the way someone might leave; he ran instead of walked out of the building. Because of this ‘twofold’ use
of this type of adverbs, there are also two specific functional heads for these adverbs; Aspect celerative(I) and
Aspect celerative(II).
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
11. Anterior tense
The adverb ‘already’ has an intrinsic meaning of ‘temporal priority’, i.e. an event time preceding a certain
reference time. Although ‘already’ often seems to express a minimal nuance, sometimes it can make a
distinctive difference:
(7)
John had gone surfing when Harry had gone swimming.
(8)
John had already gone surfing when Harry had gone swimming.
(from: Cinque, 1999)
In (7) the surfing and swimming event might co-occur. In (8) ‘already’ signals that the surfing event
happened before the swimming event. ‘Already’ is closely related to tense; specifically lowest TP;
T(anterior).
12. Terminal aspect
‘No longer’ indicates that the described event is no longer ongoing, i.e. it marks an endpoint. This does not
necessarily coincide with telic verbs, because ‘no longer’ does not have to mark a natural endpoint.
Reaching of an endpoint matches terminative aspect. This aspect is expressed through affixation in some
languages, with particles or aspectual adverbs in others.
13. Continuative aspect
‘Still’ is the positive equivalent of ‘no longer’. Contrary to terminative ‘no longer’, ‘still’ matches continuative
aspect. There is little evidence to determine whether ‘still’ and ‘no longer’ match same functional heads or
whether there are two distinct functional heads. Italian provides some evidence, because ‘no longer’
(non...più) and ‘still’ (ancora) can be used simultaneously. Whenever this happens, word order is fixed,
with “più” preceding “ancora” and not vice versa. Consequently, Cinque concludes that Aspect terminative is
located above Aspect continuative in the syntactic tree.
14. Perfect/imperfect aspect
‘Always’ appears in word orders after ‘still’ and has to be in the specifier of the functional head that comes
after Aspect continuative. The following options exist: Aspect durative and Aspect perfect/imperfect. Since
Aspect durative refers to a restricted duration, ‘always’ does not match on semantic grounds with this
functional head. In absence of clear evidence, Cinque locates ‘always’ in the specifier of
Aspect perfect/imperfect, but with a question mark.
15. Retrospective/proximative aspect
Adverbs like ‘just’ and ‘soon’ belong to the specifier of retrospective aspect. This aspect expresses that
the event occurred a short while before reference time. This aspect can be indicated with particles, affixes
and verbal periphrases, such as French “venir de ...”. In other languages such as English, Italian and
Dutch recent events are indicated with adverbs, such as ‘just/appena/net, recently/recentemente/recent,
lately/ultimamente/laatst’ etc.
Proximative aspect is the opposite of retrospective aspect, because the former aspect indicates that the
event under discussion will happen briefly after reference time. Again certain adverbs belong to this
category; ‘soon/presto/binnenkort, immediately/subito (immediatamente)/meteen’ etc.
Cinque is not sure whether Aspect retrospective and Aspect proximative belong to the same functional head. He
has found not enough conclusive evidence to state that they can or can not coincide. Therefore, these two
functional heads are regarded as one.
16. Durative aspect
If one wants to express duration of a certain period of time, one has to use durative aspect. In English and
Dutch this aspect is usually expressed with durative adverbs, such as ‘long’ and ‘briefly’ or adverbials, for
instance adverbial PP’s, like ‘for a long while’. Only durative adverbs appear in the specifier of durative
aspect head. Adverbials are, due to their composition, not compatible with a specifier position. These
adverbials surface within VP instead.
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Femke Nouwens
17. Generic/progressive aspect
This aspect does not match a specific adverb class. However, this aspect appears in the syntactic tree, so
it will not be left out. Generic or progressive aspect expresses a certain inherent characteristic of an object
which does not necessarily has to be realised yet. For instance “This car runs 280 kilometres per hour”
(from: Cinque, 1999) can be claimed about a car, which has not been on the road yet. Although Cinque is
not confident, he groups adverbs as: characteristically, inherently, typically etc. to this aspect.
18. Prospective aspect
Adverbs such as ‘almost’, ‘nearly’ and ‘imminently’ mark a point just preceding commencement of an
event. Prospective aspect is semantically connected to this type of adverbs.
19. Completive aspect
‘Completely’ or Italian “completamente” or “tutto” are specifiers of completive aspect. There are two types
of completive aspect usually coinciding with telic verbs. Telic processes have a natural endpoint, which is
intrinsic in its semantics. If the object is totally affected, the natural endpoint is reached. Particles,
auxiliaries or affixes can be used to stress this endpoint. Adverbs like ‘completely’ or ‘totally’ function
similarly. Specifiers of completive aspect are restrictively used with processes that have internal stages
and a natural endpoint.
If a plural object is present completive aspect may cause ambiguity, because two types of completion can
be referred to; that the plural set has been affected totally and that each member of the set has been
affected totally, for instance;
(9)
The group of ladies completely ate the chocolate cookies =
all the cookies have been eaten
all ladies have eaten all cookies
In English it is difficult to separate these two meanings, whereas Polish has two completive prefixes and
Italian distinguishes between “completamente” (singular completion) and “tutto” (plural completion).
From empirical evidence it turns out that completive aspect appears directly below Aspect prospective in the
syntactic tree. In this location there are two Aspect completive heads; one for the plural marker:
Aspect Pl Completive and one for the singular: Aspect Sg Completive(I). It turned out that the singular version
appears sentence final as well as the Aspect Sg Completive(II) head.
20. Voice
Empirical evidence shows that in adverb combinations the adverb ‘well’ and related adverbs follow
singular completive(I) adverbs. Cinque claims that these light manner adverbs surface in the specifier of
Voice phrase. Voice expresses the relationship between subject and verb. Theoreticians like Keyser and
Roeper (1984; in: Cinque, 1999) and Roberts (1986; in: Cinque, 1999) observed a close relationship
between manner adverbs and Middle Voice36 and Chomsky (1965; in: Cinque, 1999) among others
discovered the relationship between manner adverbs and Passive Voice37.
If it is assumed that adverbs appear in the specifier of functional head Voice, adverbs will appear to the
left of the participle. However, the other word order is available in Italian. Cinque attributes this to raising
and checking of the participle (passive past) to another feature of a higher functional head. Cinque claims
that this happens in context of a specific time reference, because the passive past participle has to rise to
higher functional generic/progressive head. The participle however fails to rise if the higher head has the
default feature ‘generic’.
36
37
Middle voice: the subject both performs and is affected by the verb (internet source: Orbilat).
Passive Voice: the subject is affected by the action of the verb (internet source: Orbilat).
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Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Appendix II: Tense in the neo-Reichenbach tense-system
Representation
R1,S38; R1,R239; E,R2
40
R1_S ; R1,R2; E,R2
R1S; R1,R2; E_R2
R1,S; R1_R 2; E,R2
Traditional naming
Present
Past/ preterit
Anterior/ present perfect
Future
R1_S; R1,R 2; E_R2
Anterior of the past/ past
perfect
Future of the past
Anterior of the future/ future
perfect/
Anterior of the future of the
past
R1_S; R1_R2; E,R2
R1,S; R1_R 2; E_R2
R1_S; R1_R2; E_R2
Reichenbach’s naming
Simple present
Simple past
Anterior present
Simple future/ posterior
present
Anterior past
Dutch example
Hij loopt.
Hij liep.
Hij heeft gelopen.
Hij zal lopen.
Posterior past
Anterior future
Hij zou lopen.
Hij zal gelopen
hebben.
Hij zou gelopen
hebben.
-
Hij had gelopen.
(adapted from: Cinque, 1999)
38
The ‘,’ that separates the E, R and S indicates that the times coincide.
R is represented by R 1 and R2 to be able to connect R to both speaking time and the event time.
40
The ‘_’ that separates the E, R and S indicates that the first time precedes the second time.
39
5
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Appendix III: Tables of raw data; division in hierarchical groups
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
B1
0
6
0
0
3
11
20
B2
1
1
3
2
1
3
11
B3
1
23
3
8
4
4
43
B4
9
5
0
2
6
5
27
B5
1
3
5
5
3
2
19
B6
0
1
1
0
1
5
8
B7
0
4
0
0
1
16
21
B8
1
10
2
3
2
1
19
B9
1
6
3
11
5
12
38
B10
0
1
1
5
12
2
21
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
N1
6
17
5
10
2
8
48
N2
3
9
2
8
1
6
29
N3
4
19
7
12
2
12
56
N4
7
18
4
13
1
5
48
N5
10
26
3
20
1
5
65
N6
2
24
2
6
2
4
40
N7
6
15
1
11
4
1
38
N8
4
31
9
10
5
8
67
N9
4
29
6
12
3
6
60
N10
2
21
2
7
2
5
39
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
W1
3
10
3
6
9
11
42
W2
7
22
6
7
6
7
55
W3
0
13
1
8
5
17
44
W4
3
12
6
13
8
15
57
W5
7
4
8
5
9
11
44
W6
16
18
5
13
7
5
64
W7
1
15
3
4
4
13
40
W8
4
13
3
6
5
13
44
W9
19
24
0
9
12
2
66
W10
2
30
8
19
4
7
70
6
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Appendix IV: Tables of relative data; division in hierarchical groups
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
B1
0.00
30.00
0.00
0.00
15.00
55.00
100
B2
9.09
9.09
27.27
18.18
9.09
27.27
100
B3
2.33
53.49
6.98
18.60
9.30
9.30
100
B4
33.33
18.52
0.00
7.41
22.22
18.52
100
B5
5.26
15.79
26.32
26.32
15.79
10.53
100
B6
0.00
12.50
12.50
0.00
12.50
62.50
100
B7
0.00
19.05
0.00
0.00
4.76
76.19
100
B8
5.26
52.63
10.53
15.79
10.53
5.26
100
B9
2.63
15.79
7.89
28.95
13.16
31.58
100
B10
0.00
4.76
4.76
23.81
57.14
9.52
100
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
N1
12.50
35.42
10.42
20.83
4.17
16.67
100
N2
10.34
31.03
6.90
27.59
3.45
20.69
100
N3
7.14
33.93
12.50
21.43
3.57
21.43
100
N4
14.58
37.50
8.33
27.08
2.08
10.42
100
N5
15.38
40.00
4.62
30.77
1.54
7.69
100
N6
5.00
60.00
5.00
15.00
5.00
10.00
100
N7
15.79
39.47
2.63
28.95
10.53
2.63
100
N8
5.97
46.27
13.43
14.93
7.46
11.94
100
N9
6.67
48.33
10.00
20.00
5.00
10.00
100
N10
5.13
53.85
5.13
17.95
5.13
12.82
100
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
W1
7.14
23.81
7.14
14.29
21.43
26.19
100
W2
12.73
40.00
10.91
12.73
10.91
12.73
100
W3
0.00
29.55
2.27
18.18
11.36
38.64
100
W4
5.26
21.05
10.53
22.81
14.04
26.32
100
W5
15.91
9.09
18.18
11.36
20.45
25.00
100
W6
25.00
28.13
7.81
20.31
10.94
7.81
100
W7
2.50
37.50
7.50
10.00
10.00
32.50
100
W8
9.09
29.55
6.82
13.64
11.36
29.55
100
W9
28.79
36.36
0.00
13.64
18.18
3.03
100
W10
2.86
42.86
11.43
27.14
5.71
10.00
100
7
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Appendix V: Tables of raw data; alternative division
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
B1
1
11
3
0
0
5
20
B2
1
4
0
5
1
0
11
B3
2
6
4
9
22
0
43
B4
8
10
1
2
4
2
27
B5
1
2
4
8
3
1
19
B6
0
6
0
1
1
0
8
B7
0
16
0
0
4
1
21
B8
3
0
2
4
8
2
19
B9
3
12
3
13
4
3
38
B10
0
4
4
5
1
7
21
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
N1
4
6
17
6
11
4
48
N2
4
7
6
4
7
1
29
N3
9
7
8
17
14
1
56
N4
10
3
7
13
15
0
48
N5
14
1
12
15
19
4
65
N6
9
4
6
4
16
1
40
N7
9
4
6
8
9
2
38
N8
13
4
10
17
19
4
67
N9
5
6
9
10
28
2
60
N10
7
3
6
5
15
3
39
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
W1
5
9
9
8
8
3
42
W2
14
4
7
15
13
2
55
W3
0
10
0
15
12
7
44
W4
3
13
6
18
10
7
57
W5
9
12
11
5
1
6
44
W6
22
7
9
12
10
4
64
W7
1
11
3
7
14
4
40
W8
4
6
5
14
11
4
44
W9
27
3
3
8
15
10
66
W10
9
1
14
18
22
6
70
8
Adverb distribution in Broca’s aphasia; a different view on the Tree Pruning Hypothesis
Femke Nouwens
Appendix VI: Tables of relative data; alternative division
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
B1
5.00
55.00
15.00
0.00
0.00
25.00
100
B2
9.09
36.36
0.00
45.45
9.09
0.00
100
B3
4.65
13.95
9.30
20.93
51.16
0.00
100
B4
29.63
37.04
3.70
7.41
14.81
7.41
100
B5
10.53
5.26
21.05
42.11
15.79
5.26
100
B6
0.00
75.00
0.00
12.50
12.50
0.00
100
B7
0.00
76.19
0.00
0.00
19.05
4.76
100
B8
15.79
0.00
10.53
21.05
42.11
10.53
100
B9
7.89
31.58
7.89
34.21
10.53
7.89
100
B10
0.00
19.05
19.05
23.81
4.76
33.33
100
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
N1
8.33
12.50
35.42
12.50
22.92
8.33
100
N2
13.79
24.14
20.69
13.79
24.14
3.45
100
N3
16.07
12.50
14.29
30.36
25.00
1.79
100
N4
20.83
6.25
14.58
27.08
31.25
0.00
100
N5
21.54
1.54
18.46
23.08
29.23
6.15
100
N6
22.50
10.00
15.00
10.00
40.00
2.50
100
N7
23.68
10.53
15.79
21.05
23.68
5.26
100
N8
19.40
5.97
14.93
25.37
28.36
5.97
100
N9
8.33
10.00
15.00
16.67
46.67
3.33
100
N10
17.95
7.69
15.38
12.82
38.46
7.69
100
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
TOTAL
W1
11.90
21.43
21.43
19.05
19.05
7.14
100
W2
25.45
7.27
12.73
27.27
23.64
3.64
100
W3
0.00
22.73
0.00
34.09
27.27
15.91
100
W4
5.26
22.81
10.53
31.58
17.54
12.28
100
W5
20.45
27.27
25.00
11.36
2.27
13.64
100
W6
35.94
9.38
14.06
18.75
15.63
6.25
100
W7
2.50
27.50
7.50
17.50
35.00
10.00
100
W8
9.09
13.64
11.36
31.81
25.00
9.09
100
W9
40.91
4.55
4.55
12.12
22.73
15.15
100
W10
12.86
1.43
20.00
25.71
31.43
8.57
100
9