PROCESSING DIFFICULTY AND
PRINCIPLES OF GRAMMAR
Gisbert Fanselow, Reinhold Kliegl, and Matthias
Schlesewsky
INTRODUCTION
Some words are more difficult to pronounce than others, and, similarly, some
sentence types are harder to process than others. Such processing differences are
due to properties of the human parser, and these may be responsible for certain laws
of natural language syntax is not a new idea: it is a key concept in linguistic
typology. This chapter investigates the merits of the proposal that two core
principles of current generative syntax, namely the principle that syntactic
movement is costly, and the principle that the costs of movement are proportional to
the distance covered (Chomsky 1995), can be explained in terms of processing
theory. The chapter is not the first attempt of relating abstract syntactic laws to
processing facts (cf., e.g., Marcus 1980, Staudacher 1993), but for such an approach
to be successful, several requirements must be met:
• assumptions concerning processing difficulty must be justified independently
• the full range of empirical facts of syntax must be captured, and,
• the approach must be explicit about the link between processing difficulty and
syntactic laws.
After introducing the facts to be explained, this chapter makes a few principled
but obvious remarks on the last aspect, to which we return in the final section. The
third section sketches the general line of the argument. The fourth section introduces evidence for the claim that movement is cognitively costly, and discusses
processing models that predict such costs. Particular attention is given to
approaches involving memory load. The fifth section tries to assess to what extent
the two key laws of syntax introduced above can be derived from such processing
considerations. The paper reports work in progress, so some of the points presently
depend more on plausibility arguments than on "hard core data".
The conclusion we will arrive at is somewhat different from the one we originally
found plausible. We still believe that the processing facts are compatible with the
view that processing shapes grammar, but there are too many gaps in the
grammaticalization account for it to be likely to be true.
PROCESSING AND SYNTAX: A SURPRISING SIMILARITY
Processes by which words or phrases are moved from their canonical position to
another belong to the inventory of operations in many if not all natural languages.
Thus, in English, direct objects of verbs typically appear in a postverbal position
(1a), but in a constituent question, a wh-object needs to be fronted, as in (1b/b').
1
(1) a. he saw it
b. he saw what ⇒⇒
b.' (guess) what he saw t
In on-line processing, local ambiguities involving the grammatical function of
such fronted wh-phrases arise frequently. Thus, clause initial what may turn out to
be the direct object of a matrix clause (as in (2a)), the complement of a prepositional phrase (as in (2b)), or the subject of a complement clause (as in (2c)).
(2) a. what did you sing t
b. what did you sing a song about t
c. what did you believe t convinced him
As was shown by Stowe (1986), among others, the human parser has clear preferences in this domain, which have been described successfully in terms of trace
theory. At least according to certain parsing theories (see Pickering & Barry 1991
for a different view), the processing of constituent questions involves the reconstruction of the relation between the actual position of the wh-phrase and its
canonical (pre-movement) position, assumed to be filled by a "trace" (represented
by "t" in (2)) in many grammatical models (Chomsky 1981). Parsing preferences in
the case of local ambiguities involving the grammatical function of wh-phrases are
correctly predicted by the assumption that the parser follows an "Active Filler
Strategy" (Clifton & Frazier, 1989), which implies that the parser tries to keep the
distance between the moved phrase and the canonical position as short as possible.
(3) Active Filler Strategy (AFS, non-canonical fomulation)
Ceteris paribus¸the parser prefers structure S over structure T if the distance
between the wh-phrase α and its trace is shorter in S than it is in T.
The AFS predicts standard processing asymmetries for English questions (see
Frazier & Clifton 1989), and seems to be responsible for the subject preference in
locally ambiguous wh-phrases established experimentally, e.g., for Dutch (Frazier
& Flores d'Arcais, 1989), Italian (de Vincenzi 1991), and German (Meng 1997,
Schlesewsky, Fanselow, Kliegl, & Krems, in press). Consider (4).
(4) a.
welche
Frau
hat t den Mann eingeladen
which ambiguous woman has theacc man invited
(wh=subject = preferred)
"which woman has invited the man?"
b.
welche
Frau
hat der Mann t eingeladen
which ambiguous woman has thenom man
invited
(wh=object = dispreferred)
"which woman has the man invited?"
The grammatical function of the wh-phrase in (4) is not determined by its morphology. The studies mentioned above report evidence that the subject interpretation is preferred by the human parser. This is in line with the AFS: German is a
subject-object-verb-language underlyingly, so the distance between the wh-phrase
and its trace t is shorter in (4a) than it is in (4b), as one can read off the
representations easily. The AFS is thus a well-supported parsing strategy.
Quite surprisingly, grammar obeys a principle similar to AFS in similar contexts:
it involves a "superiority" condition (Chomsky 1973) or a Minimal Link Condition
(MLC) (Chomsky 1995). The AFS expresses a preference for shorter links when
there is no clear evidence about the pre-movement position of a phrase. The MLC
requires that only the shorter link be formed when two phrases might undergo
movement, that is, when there also is a "local ambiguity" of rule application.
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Thus, the grammar of English requires that exactly one wh-phrase is fronted in a
constituent question. If the sentence hosts two wh-phrases, only the one that is
closer to the landing site may move, as (5) - (6) illustrate. (6) is particularly telling
since it also illustrates a subject-object-asymmetry. The observations in (5) and (6)
can be reduced to a principle such as (7).
(5) a. you persuade who to say what ⇒
b. who did you persuade t to say what
c. *what did you persuade who to say t
(6) a. you expect who to do what
b. who do you expect t to do what
c. *what do you expect who to do t
(7) Minimal Link Condition (MLC, non-canonical fomulation)
Ceteris paribus¸the grammar accepts structure S and rejects structure T if the
distance between a moved phrase α and its trace is shorter in S than in T.
From the perspective of grammar, the most interesting question about (7) is what
is meant by ceteris paribus, but for this chapter, the parallel between the grammar
and the parser implicit in (3)/(7) is the most important aspect: whenever the constitution of a chain between a moved element and a trace is not uniquely determined, the parser and the grammar prefer to (re-)construct the shortest chain. Such
similarities call for an explanation, and logically, there are three possibilities:
principles of grammar might shape the way the parser operates, it may be the other
way round, and, finally, the shape of the grammar and of the parser might be
influenced indirectly in the same way by a third causal factor. The first alternative is
discussed in detail in Fanselow, Schlesewsky, & Kliegl (1998), while the second is
in focus in this chapter. A few remarks on potential third factors can be found below
and in the other work just mentioned.
PROCESSING AND SYNTAX: HOW LINKS CAN BE CREATED
That the form of a grammar is partially determined by processing difficulty is an old
idea, but the two domains need a mediator: some sentences are difficult to process
but grammatical - multiply center-embedded relative clauses such as (8) are cases in
point. Some sentences are easy to process yet ungrammatical - as so-called thattrace-violations (9). Such observations suggest that there is a difference between the
grammar and the parser, and that the causal connection between grammaticality and
processing difficulty has to be an indirect one.
(8) the man the dog the cat the mouse feared chased bit consulted a doctor
(9) *who do you think that t loves Mary
This indirect link is "grammaticalization" (cf., e.g., Hawkins 1994 for suggestions): By a syntactic change, a process that is unlikely (or difficult) at a given
stage in the history of a language is ruled out (ungrammatical) at later stages.
Furthermore, there is a consensus that grammars change mainly because they
have to be acquired by children. Children do not have direct access to the grammar
used by the adult world, rather, they reconstruct a grammar appropriate for their
linguistic input. The result need not be identical with the adult model. If there is a
likelihood above 0.5 that changes they introduce go in one direction rather than the
other, and if languages have gone through a sufficient number of acquisitional
cycles (as they have), it is likely that most (or all) languages end up possessing a
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certain property P. Thus, any factor making certain changes even slightly more
likely than others can shape grammars quite substantially.
Suppose now that processing difficulty plays a significant role in language acquisition. That children replace a difficult option by a simpler one rather than the other
way round may be taken to be a default assumption. Thus, processing difficulty may
determine the direction syntactic changes take. After a sufficient number of
acquisitional cycles, processing difficulty can thus have had a substantial impact on
the form of grammar in natural languages.
However, this reasoning involves two assumptions that need not be correct. First,
it has to be shown that constructions that are hard to process for adults are difficult
for children, too (and vice versa) - grammaticalization implies that children's (and
not adult's) difficulties are frozen into grammar. Probably, the overlap in processing
difficulty between adults and children is substantial, so that this potential problem
does not endanger the enterprise. This may be different for the other presupposition:
it is not an established fact that the syntactic changes introduced by children
simplify the grammatical system in a processing/cognitive/grammatical sense. As
Hale (1998) has pointed out recently, syntactic change may be sporadic, and the
direction it takes may be accidental. If this is correct, grammaticalization
explanations are in trouble. See below for some remarks.
THE COSTS OF MOVEMENT
The parallel between the parser and the grammar considered above can be due to a
causal link between the two domains. An argument in favor of this view involves at
least the following steps:
(a) we must establish that movement has a cognitive cost proportional to the length
of the path independently of syntax specific heuristic parsing strategies (this
section)
(b) we must show that what characterizes the parser is sufficiently close to what
holds for grammar (We do not need to assume that their laws are identical, however, because the laws of grammaticalization may, e.g., force a form of grammar
that does not mirror processing ease in certain subdomains).
(c) one needs to be explicit about how grammaticalization works in the domain
under consideration.
We concentrate on the first issue in this section. Our argument begins with the
observation that the human parser prefers syntactic analyses that involve shorter
movement links whenever there is a local ambiguity for the grammatical function/
the pre-movement position of a moved wh-phrase. If this behavior of the parser is
due to an irreducible heuristic strategy for ambiguity resolution, it is hard to see
how it could influence the grammar of a language. What needs to be shown (or
made plausible) is that longer movement paths are cognitively more costly in
general (not just in the case of an ambiguity), and that this can be linked to the
costly nature of movement in terms of grammar.
Frazier (1987:548) speculates that subject-object asymmetries as in (4) may be
due to the greater complexity of object-initial clauses. According to her, the moved
item must be "held in a special memory buffer [...] for longer than is necessary" for
the subject initial case. Under this perspective, the validity of her Active Filler
Hypothesis (see above) derives from the assumption that the parser minimizes
4
cognitive costs in the case of an ambiguity, if the costs of a structure are related to
the amount of time for which moved items are kept in memory.
The assumption that the AFS reduces to a processing time difference between the
two competing structural hypotheses is related to the idea of "race-based" parsing:
the faster structural alternative inhibits the computation of the slower ones, a fact
that is relevant for our discussion if cognitive load is inversely related to processing
speed. The assumptions concerning items held in memory in different construction
types follow if a moved item must be kept in memory up to the point at which the
pre-movement position can be integrated into the parse tree - which can be done
earlier for subjects than for objects (see below).
This approach predicts that the additional cognitive load of object initial
structures is visible in unambiguous clauses, too. If it is costly to hold a moved item
in memory, costs should show up irrespective of whether there is an additional local
ambiguity. That this is true is suggested by findings of King & Just (1991),
according to which English object-initial relative clauses are harder to process than
subject-initial ones. Somewhat clearer evidence can be found in Krems (1984), a
study establishing that total reading times are lower for subject initial declaratives
(such as (10a)) than for their object initial counterparts (such as (10b)) even when
overt case morphology leaves no room for (relevant) local ambiguities.
(10) a. der Mann sah den Fisch
thenom man saw theacc fish
b. den Fisch sah der Mann
theacc fish saw thenom man
"the man saw the fish"
As Schlesewsky, Fanselow, & Kliegl (submitted) point out, subject-objectasymmetries in declarative (and relative) clauses are difficult to interpret because
factors independent of movement (pragmatic preferences, etc.) may favor subject
initiality. Such extrasyntactic factors play no role in the processing of constituent
questions. Therefore, we carried out a set of experiments reported in the article just
cited which studied the processing of German constituent question and which are
summarized below because they shed some light on the costs of movement.
Consider the abstract clausal grids (11) for German embedded questions:
(11) a. wh-phrasenominative
adverb-1 adverb-2
object
verb
b. wh-phraseaccusative adverb-1 adverb-2 subject
verb
c. "whether" adverb-1 adverb-2 subject object
verb
As in English, complement questions can begin with a wh-phrase (11a-b) or with
a question complementizer meaning "whether". This initial element can be followed
by adverbs, which in turn may be followed by the subject, the object, or both
(depending on what appeared in clause initial position). A series of reading
experiments comparing reading times for these (and similar) structures yielded the
following results, which are also partially visible in Experiment 1 introduced below
(see the appendix).
[A] Reading times for unambiguous clause initial wh-phrases are longer for objectinitial questions. Since subject initial questions are not favored pragmatically, the
object-initiality disadvantage in questions is a genuine formal effect.
[B] A naming task (see Schlesewsky et al. , submitted) showed that the access time
of a wh-determiner is shorter if it allows a nominative (subject) interpretation
(among others) than if it allows object interpretations only. Thus, it cannot be
5
excluded that the reading time difference introduced in [A] is partially due to a
difference in lexical access times.
[C] However, the reading time advantage for subject-initial questions continues to
be visible on the two adverbs following the initial wh-phrase. The effect was always
statistically significant for the first adverb, and was so for the second adverb in
some experiments, too - high variances in reading times on the second adverb
position may have blurred effects sometimes.
It is not likely (Schlesewsky et al., submitted) that the object-initiality effect
visible on the two adverbs is a spillover of a lexical access problem in the sense of
[B]. Therefore, there are additional costs of object-initiality. One might suspect that
this additional cost is due to a problem in the processing of sentences in which the
subject comes late (as is the case for (11b), as compared to (11a)). That such an
interpretation is not unlikely follows from the following observation:
[D] Comparing the reading times of subject-initial questions (11a) with those of
"whether-initial" questions (such as (11c), in which the subject also comes late), one
observes that reading times in the subject initial condition are shorter for the two
adverbs. Since no movement is involved in (11c), we conclude that structures with
late subjects are difficult per se - because of the position of the subject.
[E] However, a comparison of reading times for the object-initial condition (11b)
with the "whether"-condition (11c) reveals a further contrast: reading times for the
adverb are longer in the object-initial case. Since (11b) and (11c) share the property
of having a late subject, this processing difference must be due to yet another factor
- that an object is preposed in (11b), but not in (11c) is the only obvious difference.
Taking [A] - [E] together, two conclusions may be drawn: the additional costs of
object initial structures might be caused by a variety of factors: lexical access and
the difficulty of structures with late subjects come into play. But there is also an
apparently irreducible cost unit incurred by object fronting itself. It is possible that
this pure object-fronting penalty can be explained along the lines suggested by
Frazier (1987).
Note that the effect disappears as soon as the subject is encountered. German is
(underlyingly) a subject-object-verb language, and adverb positions are fairly free.
The first position in a German wh-clause at which the trace of a subject wh-phrase
can be postulated thus follows the wh-phrase itself:
(12) a. wh-subject [tsubject
adverb adverb object verb]
The object trace needs to follow the subject, though, because all objects do
(unless they change position due to processes that need not concern us):
(12) b. wh-object [adverb adverb subject tobject verb]
Thus, the pure object-initiality-disadvantage disappears when the category
immediately preceding the first legal slot for the trace of wh-movement (the
category immediately preceding the object's canonical position, if you prefer) is encountered. If parsing is strictly incremental, this means that the object-initiality
disadvantage disappears as soon as a position has been reached (viz. the subject)
which allows the postulation of the object trace and its integration into the parse
tree without violating strict left-to-right incrementality.
Arguably, the wh-phrase cannot be removed from memory unless its trace/its
canonical position has been reached in incremental left-to-right parsing. The results
of our experiments suggest, then, that additional processing time is necessary as
long as a wh-phrase is kept in memory. In this sense, movement, a process creating
the need of storing phrases up to their canonical position, is costly as such. There is
6
a cognitive cost of movement, and the time for which the additional cost arises is
proportional to the distance between the moved phrase and the trace.
This is a nice result for the general point pursued in this chapter: All current
generative models, the Minimalist Program (Chomsky 1995) and Optimality Theory
(Grimshaw 1997) take movement to be costly in grammatical terms, in the
following sense: phrases must not be moved - unless there are more important
factors forcing it.
The relation between cognitive and grammatical costs of movement is indirect,
however. This is related to, but not identical with, the observation discussed above
that grammaticalization must mediate between processing difficulty and grammar.
Our results suggest that wh-movement of question phrases is cognitively costly.
There is little empirical reason to believe that, say, the movement of a verb from
one position to another (as motivated for the grammars of French (Emonds 1978)
and German (Bach 1962, Thiersch 1978) creates a cognitive load. We are thus far
from having established that movement is cognitively costly as such.
The mediating role of grammaticalization may be helpful here, and in a further
respect. The notions of "closeness" or "distance" in grammar are hierarchical: they
involve relations such as c-command that make crucial reference to an elaborate
structural representation. It remains to be shown (and may be false) that the notion
of distance relevant for the parser is purely structural as well, and that it is identical
with the one used by grammar.
This does not, however, necessarily endanger the enterprise of deriving properties
of grammar from properties of the parser. Processing difficulty has to be
grammaticalized. This grammaticalization is triggered by processing difficulty, but
its results must fall within what is expressible in terms of grammar. Suppose, then,
(as most linguists do) that there are substantial restrictions on the terms and
relations that can appear in a grammar (or, rather, in its mental representation) restrictions that are independent of processing difficulty. Thus, in most if not all
approaches to grammar, linear distance does not play role at all. We may thus
assume that "linear distance" is not a concept that could appear in a grammar. If the
triggering factor involves linear distance, this must be translated into something that
makes sense within a grammar: hierarchical relations such as c-command among
elements in a structural representation. Anything related to linear distance that ends
up being grammaticalized is necessarily translated into a concept involving
hierarchical, structural notions of grammar. Even if the AFS crucially involves
differences in linear distance (which we do not know), grammaticalization may
translate this into the structural relations underlying the MLC. In this context, then,
it need not concern us too much whether the details of the AFS and the MLC are
identical.
This may be different for the grammaticalization of the costs of movement in
terms of a ban against unmotivated movement. After all, grammar seems to make a
distinction between verb movement and wh-movement, so it is unclear why costs of
wh-movement could not be grammaticalized in a form affecting wh-movement only,
and nothing else. On the one hand, the grammaticalization process itself might be
constrained in a way that prevents specific principles like "Don't move wh-phrases"
from arising. On the other hand, it is not obvious at all that there are movement
operations other than wh-movement. Verb movement is incompatible with a number
of fundamental assumptions of Chomsky (1995), so severel stipulations were
necessary to allow the operations. Verb movement is thus not well-founded.
7
Similarly, changes in the theory of thematic roles as proposed in Fanselow
(submitted) may make so-called NP-movement superfluous as well.
DOES IT HAVE TO BE MEMORY COSTS?
And if so, what type of memory?
Before we proceed, the role of the recourse to memory load should be clarified, and
we should be more explicit about what is understood by "memory". One
observation suggests that the "memory component" used above cannot be identified
with working memory in a cognitive psychology sense.
The work of Kemper and colleagues (Kemper 1992, Norman et al., 1991) has
demonstrated an age effect on linguistic performance that can be explained in terms
of a reduced capacity of the working memory. If a working memory load is
responsible for the additional costs of object-initial clauses, one expects a specific
age effect for object initial structures. In Experiment 1 described in the appendix,
we confronted young and old adults with sentence material with the structure of
(11), that is, we tested for possible age effects on the parameters 'early vs. late
subject' and object-initiality. Although there was a significant main effect of age
(old adults' reading times are longer), no interaction between age and any of the
syntactic factors emerged.
The results of Experiment 1 suggest that there is no particular age effect on
object-initiality. If the "memory component" causing the costs of movement would
be working memory, such an effect should have been visible. Of course, the absence
of an effect does not prove a lot, but the results of Experiment 1 are in line with
studies described in detail in Kliegl, Fanselow, Schlesewsky & Oberauer (1998),
see also Kliegl (this volume). In these studies, accuracy of comprehension was
tested for main clauses that contained a single relative clause embedding. There was
a significant age by object-initiality interaction, but just for main clause scrambling
(different in theoretical terms from wh-fronting), and not for relative clauses (close
to wh-fronting in theoretical terms -- but there was an insignificant tendency for an
age effect). In follow-up research, Junker, Oberauer & Kliegl (in prep.) show that
the age by complexity interaction did not disappear when young adults had to carry
out a secondary memory related task (as one would expect if working memory was
crucial), but it did so when presentation time was reduced for young adults. Thus,
one may at least conclude that the ageing studies have not produced evidence for
the idea that working memory in a standard sense is involved in the processing of
object-initial structure. If this is correct, the claim that recourse to a syntax-specific
memory buffer is costly for the parser is not supported independently.
The Frequency Alternative
Since the cognitive costs of movement are not likely to be caused by a load on
working memory, it is worth while to also consider a further alternative to the idea
that there is a special syntactic working memory (not affected by ageing). This
alternative to syntax-based accounts of object-initiality is a clause-type frequency
explanation. In particular in the light of the many successes of the so-called tuning
hypothesis (Cuetos & Mitchell 1988), it seems reasonable that processing speed is
related to type frequency in the case of syntactic configurations as well.
8
Versions of such approaches which ignore factors different from individual type
frequency face the problem of identifying an appropriate level of classification once
and for all. Thus, object-initial which-questions seem to be more frequent than their
subject initial counterparts (Schlesewsky et al, in press), while subject-initial whquestions seem to be at least as frequent as object initial questions in general
(Schlesewsky et al., in press, Meng 1997). Furthermore, given the heavy bias in
favor of subject initial declaratives (9:1), the total number of structures that are
object initial (disregarding further differences) is much smaller than the totality of
subject-initial clauses. Thus, it seems that any experimental result in this domain
might find a frequency explanation.
In more sophisticated approaches as used in connectionist models, processing
ease is not only determined by the frequency of individual cases, since "neighboring" similar structures are also activated. Type frequencies in these neighbor
domains therefore play a role as well, in particular if they show a clearer pattern.
Thus, MacDonald (1998) argues that the object-initiality disadvantage for relative
clauses may be due to the high frequency of neighboring 'regular" subject-initial
declaratives. In connectionist systems, the level of classification issue thus
disappears. We expect even subject initial which-questions to be easier than object
initial ones, due to the strong similarity of the former with the canonical and top
frequent standard declarative clause.
There is little psycholinguistic evidence that refutes a theory in which frequency
and similarity to regular structures account for processing difficulty: the easier
alternatives are (in most cases) the more frequent ones, or the ones most similar to
top frequent standard types. This is not the fault of the approach: facts of language
could have been different. Suppose, for example, that language L has a subject-verb
object base order, but that a conspiracy of further constraints forces the preposing
of objects in, say, 90 percent of the cases. Connectionist systems and symbolmanipulating grammatical approaches now make different predictions: ceteris
paribus, there is no reason for why the subject-initial structure should be easy to
parse in the former approaches, while the latter should predict an object-initiality
penalty due to the need of keeping preposed objects in memory.
The particular example is not likely to arise, but there is a less exotic case:
German is a verb-final language underlyingly (this word order shows up in
complement clauses), and the finite verb obligatorily moves to second position in
main clauses. From a grammatical point of view, embedded clauses should thus be
simpler than main clauses (because they involve one movement operation less)
while a connectionist model would predict that it is just the other way round
(because main clauses are more frequent). We have no evidence that decides the
issue (and recall verb movement may turn out to be non-existent), but in principle, a
comparison of the two constructions could settle the debate.
While overall results are compatible with experience based accounts, one might
claim they do not provide an explanation for the internal structure of processing
difficulty effects. This may be false, too. It is by no means established that what
matters for processing in experience based models is unanalyzable clause patterns.
Note that a segment of a clause may itself bear resemblance to a (top frequent)
clause pattern. Thus, the object initial sequence (13) resembles the top frequent
subject initial pattern from the fourth word on - recall that the object initiality effect
disappears when the subject was encountered.
(13)
wh-object adverb adverb subject .... verb
9
The latter observation already leads to the central point: in a sense, experience
based connectionist models may be able to predict "costs of movement", too.
Suppose Σ=...α..β....γ... is the canonical top frequent pattern. Suppose furthermore
β has been fronted so that ∆ = β...α ... ....γ ... arises. The reasoning proposed above
implies that ∆ should be more difficult than Σ, up to the point when we reach α. The
two models differ, of course, substantially for certain configurations, but we doubt
that data have been collected already that allow a decision between the two
approaches. Thus, there is a connectionist alternative to our memory based model
that could be correct, but if so, this does not affect the major point we wish to
discuss, viz., the likelihood of the parser shaping the form of the grammar.
The θ-prediction Alternative
The experimental findings discussed so far may be related to yet another parsing
approach. Suppose a clause c is subject-initial. C need not contain an object - after
all, the clause could be intransitive. If the human parser reacts in a conservative
way, that is, if it tries to make as few commitments as possible in terms of the
number of arguments in the clause, it will initially take subject-initial structures to
be intransitive - up to the point when there is evidence to the contrary. If the
structure is object-initial, however, it must immediately be processed as being
transitive, in order to have a chance to be grammatical at all.
Suppose that the human parser is conservative, and suppose that it is costly in
cognitive terms to keep unlinked argumental expressions or unlinked argument slots
of verbs in memory (or to pass pertinent information through the parse tree). Under
such premises, longer reading times for object initial clauses are predicted again.
Consider (14) in this respect.
(14)
α....β.... V
If α=subject and β=object, the parser operates with one unlinked argument
expression (viz. α) up to the point when it encounters β, and thus finds out that the
structure is transitive, that is, that it involves two arguments rather than one. If
α=object, two arguments must be assumed from the beginning of the clause on. We
thus expect subject initial clauses to be faster to process up to the point when the
second noun phrase is encountered - and this is what we found in our experiments.
Models based on predictions concerning argument roles and expressions (and the
costs of not having them linked) are thus in line with the experimental evidence
discussed so far. See Gibson, Hickock & Schuetze (1994) for this approach.
As in the case of the connectionist alternative, it may be pointed out that a
grammaticalization pattern might arise in response to parsing difficulty as defined
by number of unlinked thematic roles that is not much different from what it would
be in the memory theory of the costs of movement. The preposing of α creates a
difficulty because it will bring costs of (unlinked) argumental expression earlier to
bear - as long as movement goes to the left.
Consider, however, a sentence type of German exemplified in (15). The examples
in (15) involve "long" movement of a wh-phrase out of a complement clause. This
complement clause lacks a complementizer, so according to the laws of German
syntax, the verb must be preposed to the position that would otherwise be filled by
the complementizer (see e.g. Grewendorf 1988, Staudacher 1990).
(15) a. welcher Mann denkst Du kennt den Professor
whichnom man think you knows theacc professor
10
"which man do you think knows the professor?"
b. welchen Mann denkst Du kennt der Professor
whichacc man think you knows thenom professor
"which man do you think the professor knows?"
The particular composition of the examples in (15) involves a further aspect. The
wh-phrase is immediately followed by the main clause verb in (15). This verb
makes it clear that the wh-phrase has undergone long movement: In (15a), the
nominative wh-phrase is third person singular, while the verb bears explicit secondperson morphology - but subjects and verbs have to agree in German. Verbs do not
agree with objects in German, but they govern case. The verb denken "think" used
in (15) is incompatible with an (animate) accusative noun phrase object, so the case
clash rules out a matrix object interpretation in (15b). The memory and the θ-role
account of object initiality effects make different predictions concerning readings
times for these structures.
In the memory theory, one expects longer reading times for the initial wh-phrase
in the case of (15b): after all, the structure is object initial. The verb following this
noun phrase rules out the prediction that the wh-phrase is a matrix constituent in
both cases. Given that the parser processes the matrix clause when it copes with the
verb, it needs to keep both the wh-subject and the wh-object in memory. Thus,
reading times should not differ between (15a) and (15b) for the second element (the
matrix verb) and the third element (the matrix subject). The two conditions have a
chance of differing in terms of reading times only from the fourth segment (=the
complement verb) on - when the complement clause is encountered, the subject may
be dropped from memory earlier than the object (see above).
Predictions are different in accounts taking recourse to θ-theory. The number of
unlinked arguments/thematic roles that a conservative parser assumes in the presence of a clause initial nominative and accusative noun phrase, respectively, is
independent of whether this prediction is formulated for the matrix clause or for a
complement clause. Thus, the reinterpreation of the wh-phrase as a complement
clause constituent that the parser carries out when it is forced by the verb to do so
does not affect these predictions. To be more precise, the case difference of the
initial wh-phrase in (15) implies that one θ-role/argument is expected when the first
element is parsed in (15a), but that two such θ-roles/arguments are expected in
(15b). When a matrix verb like denkst is encountered, the parser realizes that the
matrix clause has two thematic roles (a subject and a clausal complement), and it
now expects one additional θ-role/argument for the complement clause for (15a),
but two such roles for (15b). Thus, the difference in the number or predicted
arguments/θ-roles is stable (in contrast to the memory account) between the two
conditions, it is just shifted to the complement clause. Only when the complement
clause verb kennt is encountered is there a chance for the difference to disappear.
The difference in load predictions between the two main approaches can thus be
summarized as in table 1:
11
Table 1
Phrases to be Difference in
memorized:
Memory
Theories
a: clause initial SI: 0
1
wh-phrase
OI: 1
b:matrix verb SI: 1
0
OI:1
c: matrix
SI: 1
0
subject
OI:1
d:complement SI: 1?
0-1
verb
OI:1?
e: 2nd NP in
SI:0
0
complement
OI:0
clause
SI: subject initial; OI: object initial
Unlinked but
predicted
θroles
SI:1
OI:2
SI:3
OI:4
SI:2
OI:3
SI:1
OI:1
SI:0
OI:0
Difference in
θ-approaches
1
1
1
0
0
The shaded areas in table 1 mark the segments of the sentences in (15) for which
one expects to see a reading time difference between the subject initial and the
object initial condition in the two theories. The experiments 2 - 4 described in the
Appendix show a clear result: there are reading time differences between the two
crucial conditions for segments (a) and (d), but not for the other segments. In this
respect, the predictions of the cost of memory theory seem to be borne out, in
contrast to what holds for the unsaturated θ-role approach.
DOES GRAMMAR CARE?
The preceding sections have summarized some evidence supporting the view that
movement is costly in cognitive terms. It is therefore conceivable that a process of
grammaticalization has shaped the form of grammars so that they respond to such
costs. In this context, the surprising parallel between the grammar and the parser
discussed in the initial part of the chapter could find an explanation.
Do grammars really care for costs of movement? They specify a (violable) ban
against movement, and a Minimal Link Condition. Let us, however, be more explicit about the former aspect. Both minimalist approaches (Chomsky 1995) and
Optimality Theory (Grimshaw 1997) assume that movement should be avoided. In
the relevant domain of wh-questions, languages should be like Japanese: there is no
movement to clause-initial position in complement questions:
(16) John-ga dare-o butta ka sirinai
Johnnom whoacc hit
Q know not
"I don't know who John hit"
Obviously, Japanese does not represent a universal pattern. After all, wh-phrases
are fronted to clause initial position in English (17). Languages such as English
might simply have been too lax in responding to processing demands, or there
might be other demands that English meets. A consideration of Chinese (18)
suggests a candidate for such further demands.
(17) what did you say t?
(18) Zhangsan zhidao she mai-le
shu
12
Z
know who buy-Asp book
"Zhangsan knows who bought books"
"who does Zhangsan know bought books"
Chinese lacks wh-movement and obligatory scope marking for question phrases.
Therefore, (18) is ambiguous: the sentences can be understood as a declarative with
an embedded indirect question, or as a question with an embedded declarative
complement clause. In contrast, wh-movement in (19) serves the purpose of what
Cheng (1997) calls "clausal typing": movement (a) identifies the type of the clause
(declarative vs. question) and (b) indicates the scope of the wh-phrase.
(19) a. who do you know that she likes
b. you know who she likes
We have to assume, then, that grammars of natural language do not only respond
to cognitive costs of movement (if they do at all) - there are other requirements that
have to be met if possible and that may override costs of movement. This in itself
does not endanger the project of deriving grammar from processing costs, but the
factor counteracting cognitive simplicity must be identified. Note that neither (a)
nor (b) can force movement as such, because clausal type can be indicated without
movement (as in Japanese (16)), and the same is possible for scope, as constructions with scope markers such as Hindi kyaa may show.
(20) a. Raam-ne kyaa socaa ki ravi-ne kyaa kahaa ki kon sa aadmii aayaa thaa
Raam-erg what thinks that Ravi-erg what said that which man came?
"which man does Rama think that Ravi said came?"
b. Raam-ne kyaa socaa ki ravi-ne kon sa aadmii kahaa ki aayaa thaa
c. Raam-ne kon sa aadmii socaa ki ravi-ne kahaa ki aayaa thaa
If (a) and (b) can be met without movement, and if movement is cognitively
costly, it is unclear why movement is tolerated when processing difficulty is
grammaticalized. This problem disappears, however, if (only if?) e.g. both [I] and
[II] hold, that is, if the scope marking strategy employed in Hindi (20a,b) itself
involves cognitive costs, perhaps comparable to the costs of movement.
[I] Movement is cognitively costly
[II] A construction Σ is cognitively costly if the syntactic scope of α in Σ does
not correspond to its semantic scope.
Obviously, the only way to respond to both processing demands (if II is correct at
all) at the same time (that is, the only way to eat the cake and keep it) is to restrict
question formation to subject questions - in which the wh-phrase does not move to
the clause initial position indicating its scope, because it already occupies this slot
in the base structure.
This option seems to characterize Kwakwala (Anderson 1984). Here, the scope of
the wh-phrase is identical with its semantic scope without creating movement costs but the price Kwakwala pays is considerable - the language has to provide many
grammatical function changing operations such as passive and apply them a
considerable number of times, because one still must be able to ask: what do you
want? (by saying: what is wanted by you?).
Typically, languages rather decide which of [I] and [II] they attribute more
weight to - [I] and [II] are two processing demands that cannot be met simultaneously. Reference to two different factors that try to pull grammar in two different
directions reduces the attractivity of the processing explanation for grammatical
principles substantially, however: recourse to processing difficulty can now simply
be dropped. A language has to "decide" whether it indicates the scope of whphrases explicitly or not, and if so, which means it uses for this. If it opts for the
13
latter, it uses what languages always use when something (grammatical function,
focussing, topicality) must be marked: morphological means or positional ones. The
domain of options seems restricted by the laws of grammar, and it seems that all
option do the job equally well. If this picture is correct, processing considerations
might come into play in a very indirect way only: if all possibilities are costly in
cognitive terms, processing does not restrict the grammars' choice.
We will leave it open here whether this is substantially different with the Minimal
Link Condition. Chomsky (1995) takes it to be an inviolable constraint of grammar,
but there is some evidence (see e.g. Müller 1998) that it can be overriden by quite
diverse other types of considerations.
IS GRAMMAR ABLE TO CARE?
One additional problem, at least in terms of the empirical foundation of an attempt
to derive grammatical costs of movement from processing costs, lies in our
complete ignorance of the mechanisms by which languages acquire or lose movement for constituent questions in their history. Ian Roberts (p.c.) suggests that
languages acquire the obligatory fronting of wh-words in questions as a reinterpretation of the (less obligatory) preposing of focussed material, in the sense
that wh-phrases represent the focus of a question.
Historical linguists are less willing to speculate on how language lose whmovement (the crucial part of the grammaticalization explanation), so we have to
offer a speculation of our own. If Anoop Mahajan (p.c.) is correct, certain
languages like Hindi allow the preposing of topicalized material in front of a
preposed wh-phrase in questions. Suppose a language L both has obligatory whfronting and optional fronting of topicalized material to the left of wh-phrases. Then
structures such as (21) can arise.
(21)
[topic: subject1 [wh-object2 [t-1 t-2 verb]]]
But the phonetic sequence of (21) allows an analysis without movement as well.
This analysis is false for language L (recall that wh-phrases have to be moved), but
if the topicalization option is chosen frequently enough, and in conversation with
children, the children might not have enough evidence for constructing the more
complex structure (21) instead of the simpler alternative (22). By this, the language
loses wh-movement.
(22)
subject object verb
If this account of the loss of wh-movement is correct, the processing explanation
of the grammatical costs of movement faces two problems: the grammaticalization
of the ban against wh-movement in the history of a language presupposes that a
language allows massive movement options in the stage immediately preceding the
breakdown of the movement analysis. In other words, prior to the loss of whmovement, children would have to go in exactly the opposite direction of what
processing difficulty would predict. And note that the final step in the process does
not make any reference to processing difficulty at all: the crucial point rather is that
the language ceases to offer clear evidence for the application of movement.
Things might even be worse. Studies on the acquisition of wh-movement by
children learning English or German reveal that children may omit auxiliary
inversion or delete the wh-phrase in early acquisitional stages -they do not try to
leave a wh-phrase in situ instead of moving it. In languages like French which
appear to allow a choice between a movement and an in situ strategy for question
14
formation, the preferences of the children are clear: they begin forming wh-question
by moving the wh-element (Weissenborn 1993).
CONCLUSIONS
The grammar and the parser (understood as a system of strategies and rules for on
line syntax processing) resemble each other in many domains. In this paper, we
have considered one particular kind of similarity, the costs of movement. Movement
can be shown to be costly in cognitive terms, and it is tempting to make such
cognitive costs responsible for corresponding aspects of the grammatical system.
Such grammaticalization accounts may seem plausible at first glance, but they
presuppose the validity of a number of assumptions that may very well be false:
(a) In general, it has not been shown so far that processing difficulty plays a
decisive role in determining the direction of syntactic changes that shape the overall
properties of natural language grammars in the long run.
(b) It is not clear whether the cognitive costs of movement are not compensated
for by other cognitive costs that arise in structures in which semantic and syntactic
scope do not go hand in hand. If so, the "balance of powers" may simply ensure that
syntactic change in the domain of question formation can go in any direction.
(c) It is not clear whether the actual path of syntactic change in the domain of
constituent question formation follows the lines predicted by a processing
optimization account.
It thus seems mandatory to look for other ways of explaining parallels between
the grammar and the parser.
15
APPENDIX: FOUR EXPERIMENTAL STUDIES
This appendix presents the results of four experimental studies which complement
experiments we have reported elsewhere but which are crucial for certain of the
points we wish to make.
With one exception, the constructional aspects of Experiment 1 are identical with
those in one study reported in Schlesewsky et al. (submitted). While the
experiments reported there focus on establishing a syntactic object initiality effect,
the purpose of Experiment 1 was to control for a possible interaction of age and
object-initiality
Experiment 1: The processing of wh-questions in old and young adults
Method
• Subjects
Thirty two subjects participated in the experiment: sixteen young adults (mean age:
20) and sixteen old adults (mean age: 69). They were native speakers of German.
They had not participated in any previous psycholinguistic experiment, and were
not familiar with the purpose of the study. They were paid for participation.
• Procedure
Subjects read the experimental material in a self-paced reading study with nonstationary presentation and phrase by phrase retrieval. The segments for phrasewise
retrieval are indicated in Table 2 below. Sentences ended with a punctuation mark.
After the presentation of the punctuation mark, the participants had to carry out a
sentence matching task. By pressing a "yes"- or a "no"-button, subjects had to
decide whether a control sentence was a verbatim repetition of the preceding
sentence. The control manipulation did not involve the proper analysis of the grammatical function of the initial wh-phrase: a negation or an adverb could be missing
or be added, or a noun could have been changed.
• Material
The experimental items were sentences of the type represented abstractly in (11).
They consisted of a main clause followed by an indirect "who"-question
(nominative or accusative initial) or an indirect whether question, see also (23).
(23) es ist egal "it does not matter"
a. wer
vermutlich glücklicherweise den Mann erkannte
whonom presumably fortunately
theacc man recognized
b. wen
vermutlich glücklicherweise der Mann erkannte
whoacc presumably fortunately
thenomman recognized
c. ob
vermutlich glücklicherweise der Mann den Dekan
whether presumably fortunately
thenom man theacc dean
erkannte
recognized
The wh-phrase was followed by two sentential adverbs, which may precede or
follow subjects in German. These were in turn followed by a noun phrase explicitly
marked for the complementary grammatical function. In the experimental items for
the "whether/if" condition, the wh-complementizer was followed by the adverbs, the
16
subject and the object, in that order. There were thus three experimental conditions
in the experimental material: subject-initial, object-initial, "whether"-initial.
The participants read five experimental items per condition, and were never
confronted with two members belonging to a single pair. There were 140 distractor
items not involving material analyzable as crucial for the contrast between the two
conditions. The segmentation for self-paced reading is given in table 2.
Results
The data of one participant had to be excluded from the analysis because of the high
error rates in the control task. Table 2 summarizes mean reading times in ms, and
accuracy in the sentence matching task in percent.
Table 2: Results of Experiment 1: All participants
Type
1
2
3
4
wh-phrase adv1
adv2
NP
compl.
wer/wen/ vermutglücklich- der/den
ob
lich
erweise
Mann
who-nom preforthe-nom
who-acc
sumably
tunately
the-acc
if
man
subject
608
600
968
906
initial
object
697
761
1092
1073
initial
if
593
602
945
982
initial
5
6
NP2
verb
den
Dekan
the-acc
dean
erkannte
-
951
-
1099
856
886
recognized
Accuracy was higher in the object initial condition (85.2%) than in both the subject
initial (76.8%) and the if-initial (73.0%) condition. A repeated measures ANOVA
showed a reading time difference between the object-initial condition on the one
hand and the other two conditions, on the other, with reading times being higher in
the object initial condition. This effect was marginally significant on segment 1
(F1(1,30) = 3.74, MSe = 309664.08, p < .07, F2(1,14) = 3.00, MSe = 99900.31, p <
.1)), and segment 4 (F1(1,30) = 7.37, MSe = 278107.63, p < .11, F2(1,14) =2.27,
MSe = 241826.48, p=.15)). It was significant both in the subject and the item
analysis on segment 2 (F1(1,30) = 17.24, MSe =183372.30, p< .01, F2(1,14) =
19.91, MSe =51064.21, p < .05)), and significant on segment 3, but in the subject
analysis only (F1(1,30) = 8.95, MSe =253162.34, p< .01, F2(1,14) = 2.50, MSe =
198408.27, p <.15)).
Table 3 summarizes mean reading times for young adults, while table 4 does so for
old adults. There was a main effect of age on reading times (F(1,30)= 12.25, p<.01),
but no interaction of age by position
17
Table 3: Results of Experiment 1: young adults (n=16)
Type
1
2
3
4
wh-phrase adv1
adv2
NP
compl.
subject
504
510
793
769
initial
object
564
637
881
954
initial
if
497
493
796
868
initial
Table 4: Results of Experiment 1: old adults (n=15)
Type
1
2
3
4
wh-phrase adv1
adv2
NP
compl.
subject
718
696
1154
1053
initial
object
838
893
1316
1201
initial
if
696
719
1105
1105
initial
5
6
NP2
verb
-
883
-
794
711
723
5
6
NP2
verb
-
1023
-
1424
1000
1060
Discussion
The overall reading time pattern found in Experiment 1 is roughly identical with the
findings reported in Schlesewsky et al. (submitted): there is a significant reading
time difference between the object and the subject initial condition, that may be
blurred on the initial segment (=1) of the embedded clause and the second adverb
(=segment 3), for the reasons discussed in the work just mentioned. The experiment
fails to show an interaction of age and object-initiality, and would therefore not
support the view that the memory necessary for the storage of wh-phrases should be
identified with standard working memory.
Experiment 2: Long movement from verb-second complements
Experiment 2 is the first of a series of studies that tries to decide between the two
major (non-frequency) accounts of the subject initiality advantage discussed above:
the idea that wh-phrases have to be memorized in a costly way vs. the idea that the
number of unlinked but predicted (bearers of ) thematic roles is the primary cost
factor. Table 1 above summarizes the respective predictions of the two theories for
an experiment measuring reading times for verb second complement clauses like
(15).
Method
• Subjects
Thirty students of the University of Potsdam participated in the experiment. They
were native speakers of German. They were neither familiar with the purpose of the
study, nor had they participated in any previous reading time experiment. They
were paid for participation, or received credits.
• Procedure
18
We employed the self paced reading technique introduced above.
• Material
The experimental items had the overall structure given in (24), and could appear in
one of the four conditions described below.
(24) a. welcher Mann denkst Du kennt den Professor
whichnom man think you knows theacc professor
"which man do you think knows the professor?"
b. welchen Mann denkst Du kennt der Professor
whichacc man think you knows thenom professor
"which man do you think the professor knows?"
c. welcher Mann hast Du
gedacht
kennt
den
Professor
whichnom man have you thought
knows
theacc professor
"which man have you thought knows the professor?"
d. welchen Mann hast Du
gedacht
kennt
der
Professor
whichacc man have you thought
knows
thenom professor
"which man do you think the professor knows?"
All clauses began with a singular masculine "which"-wh-phrase, the morphology of
which unambiguously indicated nominative or accusative case (subject- vs. objectinitial condition). The second noun phrase in the complement clause was also
morphologically unambiguous. The material was constructed in such a way that the
agreement morphology of the matrix verb excluded an analysis in which an initial
nominative noun phrase could be the subject of the main clause. That the wh-phrase
has undergone long movement out of a complement clause was therefore always
indicated unambiguously by the verb in the case of nominative initial noun phrases.
The situation is different for object initial questions. The main clauses could
either have a simple (24a,b) or a complex tense (24c,d) (simple vs. complex
condition). We selected such matrix main verbs for the experimental material that
do not accept an accusative object, so that a lexical verb following the wh-phrase
immediately forces a long movement analysis of the wh-phrases in the case of
simple matrix clauses. In complex matrix clauses, the auxiliary haben "have" is
locally compatible with a transitive matrix verb, so that the need for a long
movement analysis becomes clear only at the point when the verbal participle is
encountered. The experimental material ended with a prepositional phrase. There
were seven items per experimental condition, and 118 distractor clauses. The
segmentation for phrase-wise presentation is indicated in table 5.
Results
Table 5 summarizes mean reading times in ms and accuracy of comprehension in
percent.
A repeated measures ANOVA showed that there was a significant reading time
difference on the first segment (=the wh-phrase) between subject and object initial
questions, the former being read faster (F1(1,29)=9.73, p<.01, F2(1,7)=8.90,
p<.05). The fifth segment (=the complement verb) was read faster in subject initial
sentences than in object initial ones (F1(1,29)=5.41, p<.05, F2(1,7)=9.87, p<.01)
and faster in simple matrix clauses than in complex ones, but the latter effect was
significant in the subject analysis only (F1(1,29)=11.85, p<.01). A comparable
effect concerning the simple vs. complex condition was found on the sixth segment
19
(F1(1,29)=36.37, p<.01). There were no significant effects for the second and the
fourth segment. Reading times were faster on the third segment in the simple matrix
condition, but the effect reached significance in the subject analysis only
(F1(1,29)=20.81, p<.01).
An analysis confined to reading times for the complex matrix condition showed a
marginally significant reading time advantage for object-initial questions on
segment 2 (=auxiliary), but in the subject analysis only (F1(1,29)=3.01), p<.1). No
effects on segment 4 (=participle) approached significance. The interaction between
the two position was, however, significant in the subject analysis (F1(1,29)=5.49,
p<.03). A simple ANOVA revealed a significant main effect for accuracy
(F(3,587)=3.76, p<.01), a post hoc Scheffe test showed this to be due to a
difference in the condition simple matrix clause.
Table 5: Results of Experiment 2
1
2
3
wh=
subject
simple
wh=object
simple
wh=
subject
complex
wh=object
complex
4
5
6
7
accurac
y
which finite matrix perfect
+ N matrix subject participle
verb
complement
verb
880
610
587
631
second NP PP
in
complement
clause
721
1022 78.2
990
617
599
661
746
996
869
628
705
674
663
857
1059 81
999
585
682
690
751
829
1052 83.7
91.8
Discussion
The major result of Experiment 2 consists of an object initiality effect that appears
on exactly two segments: the wh-phrase and the verb of the embedded clause. The
higher reading times on the initial wh-phrase in the object initial condition come as
no surprise. Furthermore, there is no object initiality effect on segments 2, 3, and 4,
that is, on segments belonging to the matrix clause and to which the wh-phrase is
not related thematically. This is not in line with a model which takes the number of
predicted but unlinked (bearers of) thematic roles to be predictors of processing
difficulty, because the initial difference between two vs. one predicted thematic
roles is not eliminated but just shifted to the complement clause on segments 2 to 4.
On the other hand, the results correspond to what the memory theory would lead
one to expect.
The interaction between the reading times of segment 2 (auxiliary) and segment
4 (verbal participle) in the complex matrix clause condition reflects the pattern we
expected from the relevant aspects in the construction of the experimental material.
Recall that in complex matrix clauses the finite auxiliary forces the correct long
movement analysis for nominative wh-phrases only (due to a person/ number
20
mismatch), while the auxiliary is compatible with an interpretation of the initial
accusative wh-phrase as the direct object of the main clause. Both the interaction
between the two positions and the marginally significant reading time advantage of
object initial questions on segment 2 suggest that there is an early reanalysis effect
for nominative initial questions (the assignment of the role of subject of the matrix
clause must be retracted), but not for object initial questions in the complex matrix
condition. This pattern is expected if the participants start out with an analysis in
which the wh-phrases have not been moved out of a complement clauses, an
assumption that is in line with the Active Filler Strategy.
The reading time difference between the subject and the object initial condition
reappears on segment 5, that is, as soon as the participants begin with the
processing of the complement clause. As we have argued above, this is again not in
line with the predictions of the unlinked theta-role model, but compatible with
expectations that can be linked to the memory theory.
This reading pattern was replicated in two further studies.
Experiment 3: Possible animacy effects in the processing of wh-questions
• Subjects
Fourty two students of the University of Potsdam participated in the experiment.
They were native speakers of German. They were neither familiar with the purpose
of the study, nor had they participated in the previous experiment, or any other
reading time experiment related to our purposes. They were paid for participation,
or received credits.
• Method and Material
The method was identical with the one applied in the previous experiment. The
experimental items had the overall structure given in (24a-b), that is, the initial whphrase could either bear nominative or accusative morphology, and all matrix
clauses appeared with a simple tense form. In addition to the subject vs. object
condition, the animacy of the initial wh-phrase was systematically varied. We
confined ourselves to three experimental items for all of the four experimental
conditions (subject vs. object x [±animate)). All other aspects were kept as in the
preceding experiment. There were 138 distractor items.
• Results
Table 6 summarizes mean reading times for the segments in Table 1 in ms and
accuracy of comprehension.
A repeated measures ANOVA of reading times showed an effect in the interaction
of position and the subject-object condition that was significant in the subject and
marginally significant in the item analysis (F1(5,205) = 8.94, MSe = 27802, p <.01;
F2(5,85) = 2.14, MSe = 46568, p<.07). Sentences beginning with a subject whphrase were read faster than object initial questions independent of animacy.
Reading time differences between subject and object-initial questions were
significant on segment 1 (F1(1,41) = 25.59, MSe = 26881, p <. 01, F2(1,17) =
11,68, MSe = 28620, p <. 01) and on segment 4 (F1 (1,41) = 13.65, MSe = 38272,
p<.01, F2 (1,17) = 6.93, MSe = 42846, p<.05). No other effects reached the level of
significance, in particular, no animacy effect could be detected.
21
Table 6: Results of experiment 3
1
2
3
matrix
whfinite
subject
phrase matrix
verb
wh=
subject
animate
wh=
subject
inanimate
wh=
object
animate
wh=
object
inanimate
4
complem
ent verb
929
802
822
706
5
6
acc
second NP PP
of complement
clause
833
1138 89.7
941
779
828
745
850
1216 87.2
1104
751
816
799
848
1083 93.6
1021
760
841
873
801
1171 88
Discussion
Experiment 3 replicated the results of Experiment 2: subject initial questions are
processed faster than object initial questions, an effect that shows up both on the
morphologically unambiguous wh-phrase and on the verb in the Comp position of
the complement clause. In this respect, Experiment 3 is in line with the memory
theory of the object initiality effect, but fails to bear out the prediction of a model
working with unlinked thematic roles. Experiment 3 also shows that the animacy
cue does not contribute to this finding. Animacy has no effect on the processing of
the wh-structures under consideration.
Experiment 4: Possible frequency effects in the processing of wh-questions
• Subjects
Thirty eight high school students of a grammar school in Potsdam participated in
the experiment, all aged 18 and above. They were native speakers of German. They
were neither familiar with the purpose of the study, nor had they participated in any
previous psycholinguistic experiment. They were paid for participation.
• Method and Material
We used the self-paced reading time technique described above. The experimental
items had the overall structure given in (24a-b). In addition to the subject vs. object
condition of the preceding experiments, the following condition was added: the
noun of the initial wh-phrase could either be a high-frequency lexical item (such as
Lehrer "teacher") or a low frequency lexical item (such as Oologe "egg
researcher"). The experimental material was constructed in the following way: a
pair of a high frequency and a low frequency noun was assigned to each
complement clause verb, such that the high frequency item could appear either in
the wh-phrase and the low-frequency item in the NP remaining in the complement
clause, or vice versa, and the grammatical function as expressed by case
22
morphology was also systematically varied. There were seven items per condition
and 102 distractor items.
• Results
The data of one subject had to be excluded from the analysis, because he/she failed
to obey the instructions. Table 7 summarizes mean reading times for the segments
in (3) in msec:
Table 7: Results of Experiment 4
initial
1
2
segment
wh=phrase whmatrix
is
item
clause verb
3
4
5
6
matrix
clause
subject
505
complement 2nd NP in PP
clause verb complement
clause
642
1531
654
nominative 1010
667
high
frequency
accusative
1188
691
511
718
1414
652
high
frequency
nominative 1681
717
522
611
788
658
low
frequency
accusative
2078
695
506
696
838
662
low
frequency
A repeated measures ANOVA showed there was a significant reading time
difference between the subject and the object condition on segment 1 (F1(1,36) =
29.44, MSe = 103,828.012, p <. 001, F2 (1,25) = 18,42, MSe = 114,045.31, p <.
001) and on segment 4 (F1(1,36) = 15.62, MSe= 15,344.32, p <. 001, F2(1,25) =
5.15, MSe = 39.464.87, p<.05), which were read faster in the subject-initial
condition. Reading time difference reached significance in the high vs. lowfrequency condition on segment 1 (F1(1,36)=158.22, MSe=142,339.36, p<.001,
F2(1,25)=83.11, MSe=194,017.13, p<.001) and segment 5 (F1(1,36)=79.65,
MSe=202,054.07, p<.001, F2(1,25)=45.58, MSe=238,963.07, p<.001). No other
effects reached the level of significance.
• Discussion
With respect to the subject-object-condition, Experiment 4 replicated the results of
the preceding two experiments: there is a stable advantage in reading times for
subject-initial structures showing up on the wh-phrase and on the complement verb.
The pattern strongly supports the memory explanation of the object initiality
disadvantage, and is not compatible with the predictions of an approach that takes
the number of unlinked (bearers of) thematic roles to be crucial.
With respect to the high vs. low-frequency condition, experiment 4 yielded
results that would be expected under nearly any theory of lexical access: reading
times were higher for NPs containing a low-frequency noun, irrespective of the
structural position in which this NP shows up. This frequency effect cannot,
however, be detected on the verb of the complement clause.
23
ACKNOWLEDGEMENTS
Parts of this paper have been presented at the Sedona workshop, and on various
other occasions at the Universities in Delhi, Groningen, and Stuttgart. We would
like to thank the participants of the Sedona workshop, and the audiences in Delhi,
Groningen, and Stuttgart for their comments and suggestions. Thanks also go to Ina
Hockl, Martina Junker, Klaus Oberauer, Douglas Saddy, Peter Staudacher for hints
and discussion, and to Petra Grüttner and Hannelore Gensel for technical support.
We are particularly indebted to Susan Kemper, Anoop Mahajan, and Gereon
Müller for helpful discussions that had a substantial impact on the present paper.
The research reported in this paper was supported by the grant INK 12/A1, the
Innovationskolleg "Formal Models of Cognitive Complexity", financed by the
German Federal Ministry of Science and administered by the German Research
Foundation.
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