JISHA 25 (2), 98-112
Discourse in Dementia
Cognitive Linguistic Abilities and Discourse Production in Bilingual
(Kannada - English) Persons with Mild Dementia
Deepa M.S & Shyamala K. Chengappa
Abstract
Discourse is a way of expressing ideas and thoughts between two conversational partners. Discourse has
been assessed at different levels and has been qualified as well as quantified for clinical populations such
as aphasia, dementia, traumatic brain injury. Dementia is a progressive neurodegenerative disorder which
affects individual’s communicative abilities. The inability of effective communication in persons with dementia
may be due to the progressive loss of cognitive skills. The present study investigated the cognitive decline
and discourse abilities in persons with mild dementia. Considered for the study were 60 healthy elderly (30
monolinguals and 30 bilinguals) and 20 persons with mild dementia (10 monolinguals and 10 bilinguals). All
the participants underwent testing for cognitive linguistic assessment and discourse measures. Addenbrooke’s
Cognitive Examination Revised (Krishnan & Lokesh, 2010) and Cognitive Linguistic Assessment Protocol
(Kamath & Prema, 2001) with modifications suggested by Rajasudhakar and Shyamala (2008) were used
for cognitive linguistic assessment. Discourse data was collected for picture description and conversation.
Discourse was analyzed using t-unit based analysis. Discourse production as against the performance in
cognitive linguistic tests is discussed.
Key words: bilingualism, cognitive decline, communication
story grammar analysis involves episode counts and
proportion of utterances in episodes (Karen, Mozeiko
& Coelho, 2011). The present study focuses on
across sentence analysis as measured using t-unit
based measures for narrative and conversational
discourse genre.
Discourse studies were the major foci during 1930s.
It has been widely used for both normal and clinical
population. The studies which concentrated on normal
discourse analyses were interested in quantifying the
differences in utterances among younger and older
individuals. In clinical studies, the discourse has been
qualified and quantified for disordered populations
such as aphasia, dementia, traumatic brain injury and
so on. Dementia is a general term describing a group
of disorders in which memory and thought processes
(cognition) become impaired for a period of at least 6
months (Allen, 2000).
Dementia means loss of mental functions. It is an
acquired, persistent impairment in multiple areas of
intellectual function not due to delirium. Operationally,
there is a compromise in three or more of the
following nine spheres of mental activity: memory,
langauge, perception (especially visuospatial),
praxis, calculations, conceptual or semantic
knowledge, executive functions, personality or social
behavior, and emotional awareness or exression.
The compromise in mental functions is documented
by mental status assessment, either by bedside
mental status evaluation, clinical rating scales, or
neuro psychological testing (Mendez & Cummings,
2000, p.4).
Discourse is defined as a basic unit of human
social communication (Brownwell & Joanette, 1993).
Discourse genres are separated into two broad
categories: monologic (monologues) and interactive.
These a re further divided into conversational,
procedural, expository and narrative. Descriptive
discourse includes attribution of features and
concepts of a given stimulus (e.g., object) or personal
experience (e.g., favorite hobby). Narrative discourse
involves telling of a story, typically through generation
of a spontaneous story or retelling a story previously
presented. Procedural discourse is the explanations
of action sequences to perform a task. And finally,
expository discourse informs a listener of a topic
through facts or interpretation, drawn upon higherlevel thinking skills (e.g., inferencing, understanding
cause and effect).
Discourse can be assessed at various levels
using various methods. The levels of discourse
analyses include within-sentence analyses, across
sentence analyses, text-level analysis and story
grammar analyses. Within-sentence analyses assess
sentential complexity, propositional analyses and
counts, verbal output errors (e.g., mazes, lexical
errors, verbal paraphasias), productivity and essential
content units. Across-sentence analyses assess
cohesive adequacy, cohesive errors and usage
patterns for cohesive markers. Text-level analyses
are concentrated on local and global coherence,
and gist summarization of the utterances. Finally, the
All India Institute of Speech and Hearing, Mysore
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JISHA 25 (2), 98-112
Discourse in Dementia
The International Statistical Classification of
Diseases and Related Health Problems of 10th
Revision (ICD-10, WHO, 1992), have categorized
dementia into the cortical dementias and the subcortical dementias based on which part of the brain
is affected. Cortical dementias arise from a disorder
affecting the cerebral cortex, the outer layers of the
brain that play a critical role in cognitive processes
such as memory and language. Alzheimer’s and
Creutzfeldt-Jakob disease are two forms of cortical
dementia. Sub-cortical dementias result from
dysfunction in the parts of the brain that are beneath
the cortex. Examples of sub-cortical dementias
include Huntington’s disease, Parkinson’s disease,
and AIDS (Acquired Immunuo Deficiency Syndrome)
dementia. Present study has considered only cortical
dementias (Dementia of Alzheimer’s type (DAT),
vascular dementia, mixed dementia, and frontotemporal dementia).
There are various stages of dementia and each
stage demarcates clearly the changes in cognitive
and linguistic performances in them. There are 7
stages of dementia ranging from very mild cognitive
decline to very severe cognitive decline (Alzheimer’s
Association, 2011). For understanding the decline
in language abilities, these stages can be broadly
classified into mild, moderate and severe stages.
In the mild stage, there are few errors in naming
task and they find difficulty with story-level material.
But the discourse is usually intact and they can
attend to simple questions. In moderate stage, there
are many errors in naming task and they are unable
to answer questions. They require prompting to begin
conversation. Marked difficulty is seen in planning
& organization skills. Reduction in memory of
personal history as well as poor short-term memory
is noticeable. In the final stage, that is, in the severe
stage, naming is severely impaired and they may
use jargon. Impairment of short-term and long-term
memory is evident. They have impaired abstract
thinking, judgment, disturbances of higher cortical
functions and/or personality. Personality changes
are significant along with behavioral symptoms. They
also produce unintelligible speech (Jeon & JoonSeok, et. al., 2008).
Hence, the mild stage is more sensitive for the
discourse measurement. And significant difference
can be evident between healthy elderly and persons
with dementia during this stage. There are many
investigations related to bilingualism and aging (e.g.,
Bialystok, Craik, & Freedman, 2007; Salvatierra &
Roselli, 2011). According to these studies, bilingualism
may provide an advantage to older adults on inhibitory
control tasks. Bilingualism increases skills that are
associated with selective attention when working
memory demands are low. So it is important to known
about the cognitive functioning in bilingual speakers
with dementia. Apart from the linguistic analysis in
dementia there were also studies which assessed
the pattern of language deterioration in bilingual
contexts (Hyltenstam & Obler, 1989; Rabadán, 1994;
Baker, 1996 and McMurtray, Saito, & Nakamoto
2009). Communication abilities in bilingual speakers
with dementia and the pattern of language decline
for L1 (first language) and L2 (second language)
in dementia are issues that are rarely mentioned
in the dementia literature. It is understood that
persons with dementia not only manifest linguistic
deficits but also cognitive-communicative difficulties.
Cognitive-communication
disorders,
including
discourse impairments associated with dementia,
may be related to a disruption of executive functions
(Ylvisaker & Szekeres, 1989).
Discourse abilities in persons with dementia
Attempts have been made to study and compare
various aspects of discourse, using both qualitative
and quantitative measures, in persons with different
types of dementia. Mendez, Perryman, Ponton and
Cummings (1999) studied 51 bilingual persons
with dementia for fluency in English using general
conversation. Persons with dementia (PWD)
presented an evident tendency for words and
phrases from native language to intrude into English
conversational speech. They tended to present
asymmetrical language impairment with preferential
preservation and use of the first acquired language.
So it is evident that each of the languages spoken by
these individuals needs to be assessed separately to
determine the affected and preserved skills in those
languages. Linguistic measures in spontaneous
conversational speech in persons with DAT were
analyzed by Bucks, Singh, Cuerden and Wilcock
(2000). They considered 24 participants (8 persons
with dementia and 16 healthy elderly) and measured
noun rate, pronoun rate, verb rate, adjective rate,
clause-like semantic units (CSU), type token ratio
(TTR), Brunet’s index (W) and Honore’s Statistic (R).
The results revealed that the measures offered a
sensitive method of assessing spontaneous speech
output in persons with DAT and they can also be used
as prognostic tools in clinical trials. It is hypothesized
that visuoperceptual and attention ability are
disproportionately impaired in persons having
dementia with Lewy Bodies (DLB) compared with
Alzheimer’s disease (AD). Persons with DLB have
substantially greater impairment of attention, working
memory, and visuoperceptual ability than persons
with AD matched for overall dementia severity.
Semantic memory seems to be equally affected in
DLB and AD, unlike episodic memory, which is worse
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Discourse in Dementia
in AD (Calderon, Perry, Erzinclioglu, Berrios, Dening,
& Hodges, 2001).
Silveri, Reali, Jenner and Puopolo (2007) aimed
to investigate whether attention may be specifically
impaired in the early stages of Alzheimer’s disease.
Subgroups of persons with different types of mild
cognitive impairment were selected according
to standard criteria. Persons with dementia and
healthy elderly were given tasks exploring various
subcomponents of attention and executive functions.
Only subgroups of mild cognitive impairment
characterized by memory disorders obtained lower
scores than controls on attention and executive tasks.
The results suggest that not only memory disorders
but also attention/executive deficits may characterize
dementia at the onset.
Cognitive process in mild Dementia
As the definition of dementia states, it is the
disorder of decline in cognitive skills in relation to the
progression of the disease. This decline varies across
stages and sometimes across the types of dementia.
The processes which are prone to decline include
memory, executive function, attention, concentration,
perception and visuospatial skills. These processes
may be directly or indirectly involved with the
communication abilities of persons with dementia.
Memory problems are typically the first signs of
cognitive decline across dementia. Memory problems
often result in the problem behaviors which can be
explained by failure at different aspects in memory
processing. There is evidence of reduced memory
span and short term memory (STM) capacity in
dementia (Morries, 1986). Persons with dementia
have increased rate of forgetting (Alma, Chan & Chiu,
2003) and have impairment in the ability to learn and
remember new information but they have relatively
preserved recognition and increased performance
with cueing (Hoppe, Muller, Werheid, Thone &
Cramon, 2000). Persons with dementia have difficulty
in more complex tasks which require divided attention
such as listening for target word in a list (Perry &
Hodges, 1999). Attention for simple tasks of only
selecting and sustaining are not typically impaired
in early dementia (Assal & Cummings, 2003). Intact
focusing and impaired disengagement of visuospatial
attention may be linked to dysfunction in early stage of
DAT of cortico-cortical networks linking the posterior
parietal and frontal lobes (Parasuraman, Greenwood,
Haxby & Grady, 1992). The components of executive
function (EF) (Assal & Cummings, 2003) such as
planning, shifting, mental set, inhibiting incorrect
responses, manipulating new information, violating
purposive action, self monitoring are affected at early
stage of dementia and causes difficulty in performing
instrumental activities of daily living. EF for complex
tasks and problem solving declines with increase in
severity of dementia (Voss and Bullock, 2004).
Relationship between language use cognitive
abilities
Literature supports the view that there exists a
relationship between discourse production and
cognitive functioning. Linell (1998) explained that it
is worth noting that studies of cognition are governed
by the idea of individual’s cognition. The goal of the
analyses and their focus has been on the processes
that take place when people communicate with one
another in situational and socio-cultural contexts.
Beaugrande (2001) proposed a dialectical model
to explain the relationship with language use
(discourse) and cognition. According to this model, all
human practice produces knowledge, which is stored
as the contents of cognition. The model proposes
that language must have originated and evolved as
a refined meaning for delimiting, organization, and
stabilizing those contents into meanings, and for
sharing, the meanings, among the community. Also
the content of cognition and content or meaning of
language in use is thus phenomenon of the same
order. Hence cognition and language use is thus
interacting in a dialectical cycle with each side
informing and guiding the other. Cognition generates
meanings, whereas language in use determines
meanings. Hence there is direct relationship between
language use and the cognitive skills.
Ash, Moore, Antani, McCawley, Work, and
Grossman (2003) assessed discourse in persons
with frontotemporal dementia (FTD), progressive
non-fluent aphasia (PNFA), and semantic dementia
using social comportment and executive functioning
to narrate the story of a wordless children’s picture
book. They found qualitatively significant discourse
impairments in the clinical group. Persons with PNFA
had the minimal output, producing narratives with
the fewest words per minute. Persons with semantic
dementia had difficulty in retrieving words needed
to tell their narratives. Persons not using social
comportment and executive functioning had profound
difficulty in organizing their na rratives, and they were
unable to express the point of the story. This deficit
correlated with poor performance on a measure of
executive resources requiring an organized mental
search.
Castello, Brandio, Teun, Parente, and Caranova
(2009) investigated cognitive and linguistic
mechanisms involved in knowledge management
during discourse production of persons with
Alzheimer’s disease. Two discourse variables were
studied, incomplete propositions and repeated
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Discourse in Dementia
propositions. Difference between normals and
persons with Alzheimer’s disease were found in terms
of presence of incomplete propositions in a noninformative prompted task. Findings obtained from
informative prompted task suggested that knowledge
management was more preserved in early stage than
in the later stages of the disease. The majority of
neuropsychological data correlated with the presence
of incomplete propositions. Discourse deficits were
attributed to an impairment of the ability to manage
knowledge provided in the context of communication.
Bilingualism and dementia
Apart from cognition, the effect of bi/multilingualism
on the language comprehension, languages
production and cognitive functions were studied in
recent years. Bialystok, Craik & Freedman in 2007
analyzed the clinical records of 211 persons with
dementia who had been diagnosed with probable
Alzheimer’s over a two-year period. Among them,
102 persons with dementia were identified as
bilingual and 109 as monolingual. An evaluation of
the persons with dementia revealed that those who
spoke two languages had been diagnosed with
Alzheimer’s disease 4.3 years later and reported the
start of symptoms five years later than patients who
spoke only one language.
Ardila and Ramos (2010) inferred that language
mediates not only the social relationship systems, but
also the control of cognitive processes. They inferred
that potential differences exist between exist bilinguals
and monolinguals in age-associated cognitive decline
during normal and pathological ageing. According
to them, normal aging is associated with increased
interference between the two languages. Regression
to the primary language can be considered as a
predictor of dementia.
According to Dementia India Report (2010), the
overall prevalence of dementia is estimated as 3%.
It is estimated that there are about 1.5 million people
with dementia in India (compared with 2.9 million
in the USA).This number is likely to increase by
300% in the next four decades. Impaired discourse
is the hallmark of cognitive-communication disorder
due to the central role discourse plays in everyday
communication. The extent of discourse impairments
in persons with dementia influences the diagnostic
process, formulation of prognosis, and development
of effective interventions for social reintegration.
The purpose of the present study was to determine
whether a generative discourse production task
distinguished typical older adults from adults with
dementia with the quantitative measure of discourse.
Particularly the study focused at the relationship
between cognitive linguistic functioning and generative
discourse abilities in persons with dementia.
Sample
Method
The study considered a total of 80 participants.
Among them, 60 participants belong to the normal
group with healthy elderly (30 monolinguals and 30
bilinguals) and 20 (10 monolinguals and 10 bilinguals)
participants are from clinical group consisting of
persons with mild dementia. The age range of
the participants was between 65-85 years. These
participants were same as those who participated
for the research ‘Bilingual Dementia –Spectrum of
Cognitive Linguistic Function’ (Deepa & Shyamala,
2010).
Inclusion criteria for the group with healthy elderly
The study considered certain inclusion and
exclusion criteria before selecting the participants.
The inclusion criteria for the group with healthy
elderly required that, all the participants should have
a minimum of 12 years of formal education, Kannada
as their first language (L1) and English as their
second language (L2) (for bilingual participants). The
healthy elderly should have vision and hearing acuity
corrected to normal / near normal limits. Healthy
elderly participants should not have history of any
neurological or psychological problems and should
not be complaining of memory or other cognitive
difficulties. A score of 25 and above in Mini-Mental
Status Examination (MMSE, Folstein et al., 1975)
and a score of “0” in Clinical dementia rating (CDR,
Hughes, Berg, Danziger, Coben & Martin, 1982) was
required for healthy elderly group.
Inclusion criteria for the group of persons with
dementia
The participants from the clinical group had a
minimum of 12 years of formal education. They had
Kannada as their first language (L1) and English as
their second language (L2) (for bilingual participants).
They had vision and hearing acuity corrected to normal
/ near normal limits. The participants from clinical
group scored less than 20 in MMSE. For clinical
group, a score of “1” (mild) from clinical dementia
rating scale was considered to categorize them to
mild dementia. A diagnosis of probable dementia was
made according to DSM IV criteria. Each participant
from the clinical group attended the geriatric clinic at
National Institute of Mental Health and Neurosciences
(NIMHANS) where they underwent thorough medical
screening in order to rule out any other treatable
pathology that could explain their impairment.
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JISHA 25 (2), 98-112
Discourse in Dementia
This included neuropsychological assessment and
Computerized Tomography (CT) scanning of the
head. MMSE was administered during the initial
work out by psychiatrist after which the persons were
diagnosed as having mild dementia.
Table 1. Age, years of education, and handedness of
all the participants, and duration of illness for persons
with dementia.
Healthy
elderly
N= 60
Participants with
dementia
N= 20
M
SD
72.6yrs
6.39
70.8yrs
6.97
Yrs. of education 12.8yrs
1.68
11.9
2.46
7.7months
1.82
Age
Duration of illness
Handedness
-Right
M
SD
The clinical groups were matched with normal
groups for age, education and handedness. The
details of the number of participants, age in years,
education in years and handedness is depicted in
Table 1. Table 1 also shows the duration of illness for
persons with dementia.
Table 2 shows the demographic and neurological
details of the participants from clinical group. Decline
in cognitive skills (as measured using MMSE and
Addenbrooke’s Cognitive Examination Revised),
education and age were the major parameters used
to consider the participants for the study.
Material
right
(M = mean, SD = Standard deviation, N = number of
participants).
Included in the study were two test protocols
for assessing cognitive linguistic skills in elderly
population. These tests include Addenbrooke’s
Cognitive Examination Revised (ACE-R, Krishnan &
Lokesh, 2010) and Cognitive linguistic assessment
protocol (CLAP, Kamath & Prema, 2001) with
modifications recommended by Rajasudhakar
Table 2. Demographic and neurological details of participants with demention.
Sl Age/
no. sex
CDR
score
Monolingual/ Diagnosis of
bilingual
dementia
Neuroimaging result
1 67/f
1
M
Mild AD
Bilateral medial temporal atrophy
2 72/f
1
M
Mild AD
Diffuse central atrophy
3 69/f
1
M
Mild Frontotemporal
Left fronto-temporal atrophy
4 68/m
1
M
Mild Frontotemporal
Bilateral fronto-temporal lobe atrophy
5 84/f
1
M
Mild AD
Bilateral medial temporal atrophy
6 68/m
1
M
Mild AD
Diffuse brain atrophy
7 66/m
1
M
Mild AD
Bilateral sub-cortical infarcts
8 71/m
1
M
Mild vascular
Multiple cerebral infarcts
9 69/m
1
M
Mild frontotemporal
Left fronto-temporal atrophy
10 75/m
1
M
Mild AD
Bilateral medial temporal atrophy
11 67/f
1
B
Mild AD
Bilateral medial temporal atrophy
12 70/f
1
B
Mild AD
Diffuse central atrophy
13 69/f
1
B
Mild Frontotemporal
Left fronto-temporal atrophy
14 68/m
1
B
Mild Frontotemporal
Bilateral fronto-temporal lobe atrophy
15 82/f
1
B
Mild AD
Bilateral medial temporal atrophy
16 68/m
1
B
Mild AD
Diffuse brain atrophy
17 65/m
1
B
Mild AD
Bilateral sub-cortical infarcts
18 72/m
1
B
Mild vascular
Multiple cerebral infarcts
19 70/m
1
B
Mild Frontotemporal
Left fronto-temporal atrophy
20 73/m
1
B
Mild AD
Bilateral medial temporal atrophy
(CDR= Clinical dementia rating, m= male, f = female, AD = Alzheimer’s dementia, M = monolingual, B = bilingual).
102
JISHA 25 (2), 98-112
Discourse in Dementia
and Shyamala, (2008). Addenbrooke’s Cognitive
Examination Revised (ACE-R, Krishnan & Lokesh,
2010) is a test of cognitive assessment in dementia.
The test consists of subtests on attention and
orientation (18), memory (26), verbal fluency (14),
language (26) and visuospatial abilities (16). The
maximum score for the test is 60. CLAP consists
of domains such as attention (60), perception &
discrimination (60), memory (60), problem solving
(60) and organization (60). Each task contained a
score of 1 for correct and 0 for the incorrect response
in both the tests.
Clinical dementia rating scale was given by Morris
(1993) and was used to categorize the severity of
symptoms of dementia. It consisted of six areas:
memory, orientation, judgment and problem solving,
community affairs, home and hobbies, and personal
care. Scores in each of these are combined to
obtain a composite score ranging from 0 through 3.
Zero suggests very mild and three implies severe
impairment. For categorizing participants into
monolinguals and bilinguals International Second
Language Proficiency Rating Scales by Wylie &
Ingram, (2006) was used. The scale was designed
to measure general proficiency or practical language
skills in real-life language contexts for learners of a
second or foreign language. The scale checks four
parameters which are, speaking, listening, reading,
and writing. Scoring in the scale ranges from 0 to 5
(0 stands for zero proficiency and 5 stands for native
like proficiency). A score of “3” suggests vocational
proficiency which is enough for a particular language
to elicit discourse genres. In this study, the participants
who scored “3” and above in English were included in
bilingual group.
Procedure
Four groups were considered for the study. Two
clinical groups consisted of persons with mild
dementia (10 monolingual and 10 bilingual). They
were recruited from National Institute of Mental Health
and Neuroscience, Bangalore, India and Nightingales
Medical trust, Bangalore, India. These clinical groups
were compared with two groups of 60 healthy
elderly (30 monolingual and 30 bilingual) matched
for age and education. All persons with dementia
underwent clinical and radiological (CT or MRI or
SPECT) assessment. Participants were classified
into dementia and healthy elderly groups, according
to DSM-IV criteria (APA, 1994). The participants
were interviewed and the general history was taken.
General history included the demographic details of
the participants, education history, language history,
medical history, present health status and any other
associated problems Followed by the general history,
a written consent was taken from all the participants
regarding their willingness for the participation in the
study. Language proficiency was measured using
International Second Language Proficiency Rating
Scales by Wylie & Ingram (2006). Based on the
scale, participants were categorized into monolingual
and bilingual i e., a score of 3 and above shows
vocational to native like proficiency for speaking,
reading, listening and writing. Hence, a cut off score
of 3 and above (in both Kannada and English) in
all the four categories was used for considering the
participants as bilinguals. The scale was administered
for monolinguals in Kannada and for bilinguals it was
both in Kannada and English. Those participants with
scores of three and above were considered for the
study. The clinical groups and the groups with healthy
elderly were studied and compared for CLAP and
t-unit based analysis.
Data collection
Data was gathered for both the groups on cognitive
linguistic performance (ACE-R and CLAP) and
generative discourse. The generative discourse
genres were collected using two tasks (a picture
description and a conversation task). For the picture
description task, two coloured pictures were used,
a “village scene” and a “city centre”. Each picture
was 12 x 8 inches in dimension. Participants were
instructed to describe the events happening in the
pictures. They were asked to name all the contents in
the picture and describe the same from left corner to
right corner of the picture in an order. It was difficult to
elicit descriptive discourse from the clinical population
for line drawings as they were unable to pay attention.
Hence, coloured pictures were used.
For the
conversation task, two topics were selected that is,
‘differences in present generation as compared to the
older generation’ and ‘description about conducting
a marriage at home which is going to take place in a
month’. Open ended questions which did not restrict
or control either the extent or the nature of their
response were asked. Unless required/requested, no
obvious cues were provided to the participants Each
Interview was video recorded using a Handy cam
(Sony digital recorder H302233). Interviews lasted
between 15-25 minutes to collect at least 700 words
of conversation from each participant.
Data analysis
The discourse data obtained from the clinical
and non-clinical participants were compared using
appropriate statistical analyses. In this study, the
clinical groups were categorized based on cognitive
decline and not based on type of dementia. There
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JISHA 25 (2), 98-112
Discourse in Dementia
are many types of dementia but only three types of
dementia with mild degree of cognitive decline were
considered for this study. And the pattern of decline
was similar across the clinical participants within the
group. Initial part of analysis was for the performance
in the tests of cognitive linguistic skills. For the clear
picture about performance in ACE-R, the scores are
graphically represented (Figure 1 and Figure 2). This
test was mainly used to see the pattern of cognitive
decline in mild dementia. The scores of CLAP were
tabulated and are discussed in the following section.
The video recorded samples were transcribed
verbatim for the purpose of analysis. Interviews
were transcribed using IPA (International Phonetic
Alphabet) rules. Words spoken by the participants and
the experimenter were transcribed. Initially all words
were transcribed exactly as they had been spoken.
These included repetitions, incomplete words,
interjections, paraphasias and mispronunciations.
Subsequently, the sample was rephrased deleting
repetition, incomplete words and interjections and
was therefore not counted for analysis. Stereotypical
set phrases such as, “ninig gotta” (you know)
“alvamma” (right girl) were excluded, because such
expressions were not acceptable as proper clauses or
full sentences. Numbers were transcribed as words.
A t-unit based analysis was used to analyze
discourse. The T-unit is defined as one independent
clause plus the dependent modifiers of that
clause (Hunt, 1974). It is defined as the “shortest
grammatically allowable sentences (into which writing
can be split) or minimally terminable unit.” Often, but
not always, a T-unit is a sentence. T-units are often
used in the analysis of written and spoken discourse,
such as in studies on errors in second language
writing. A clause is a part of a sentence. There are
two main types: independent (main clauses) and
dependent (subordinate clauses). An independent
clause is a complete sentence; it contains a subject
and verb and expresses a complete thought in both
context and meaning. Independent clauses can be
joined by a coordinating conjunction to form complex
or compound sentences. A dependent (subordinate)
clause is part of a sentence; it contains a subject and
verb but does not express a complete thought. They
can make sense on their own, but, they are dependent
on the rest of the sentence for context and meaning.
They are usually joined to an independent clause to
form a complex sentence. Dependent clauses often
begin with a subordinating conjunction or relative
pronoun (see below) that makes the clause unable
to stand alone.
Fig.1. Individual scores of ACE-R for monolingual
persons with Dementia (MD = monolingual persons
with dementia).
Fig.2. Individual scores of ACE-R for bilingual persons with Dementia (BD = bilingual persons with dementia).
Results and Discussion
Figure 1 and Figure 2 depicts the results of ACE-R
for the monolingual and bilingual group of persons
with dementia (PWD) respectively. Though diagnosis
of dementia was different all the individuals were
grouped together based on similar pattern of cognitive
decline as seen from the results of ACE-R. The
overall comparison of the scores for the two groups
and categories are shown in Table 3. Table 3 shows
the results of descriptive statistics for CLAP with
respect to the two groups (healthy elderly and persons
with dementia) and two categories (monolingual and
bilingual) It can be observed from the table that the
standard deviation for the clinical group was higher
as compared to the group with healthy elderly in most
of the parameters of CLAP.
Comparison between the groups and categories
for CLAP
A two way MANOVA was administered to see
the main effect of group, category and interaction
between the two for APD (Attention, Perception and
Discrimination), ME (Memory), PS (Problem solving),
OR (Organization) and CLAPT (Cognitive linguistic
assessment protocol total) of CLAP. As it is seen from
Table 4, the main effect of group was significant for all
the five parameters of CLAP or dependent variables
at p<0.01. With respect to the categories (monolingual
104
JISHA 25 (2), 98-112
Discourse in Dementia
Table 3. Results of descriptive statistics for CLAP with respect to the two groups and categories.
Group
Parameters
Category
Healthy elderly (HE)
Mean
APD
ME
PS
OR
CLAPT
Std. Deviation
Persons with Dementia (PWD)
N
Mean
Std. Deviation
N
Mono
57.63
2.14
30
49.80
2.25
10
Bi
59.30
.79
30
51.10
1.72
10
Mono
31.41
1.88
30
27.50
1.08
10
Bi
32.30
1.27
30
28.60
1.71
10
Mono
37.33
1.86
30
20.70
1.33
10
Bi
33.60
1.56
30
23.40
1.34
10
Mono
53.26
4.93
30
28.80
1.22
10
Bi
57.06
2.70
30
37.30
1.25
10
Mono
179.65
7.96
30
126.80
3.79
10
Bi
182.26
3.86
30
140.40
3.40
10
(APD = Attention, Perception and Discrimination, ME = memory, PS = Problem solving, OR = organization,
mono = monolingual, Bi = bilingual, N= number of participants).
and bilingual), there was highly statistical significance
for all the parameters of CLAP except for the problem
solving skills at p<0.001 level.
Although the actual difference in the mean
scores were typically small, many of the differences
between mild dementia group and healthy elderly
were statistically significant. There was a significant
difference in scores for items measuring abstract
naming, fluency, understanding of complex structures
and conceptual processes were impaired in mild
dementia. Statistically significant difference was
observed between monolingual and bilingual groups
for OR and CLAPT, whereas APD, ME, and PS did
not show any difference between monolingual and
Table 4. Results of two way MANOVA with respect to
group and category.
Groups/
categories
Parameters
F(1,76)
Healthy elderly APD
Vs
ME
Dementia
PS
OR
CLAPT
327.4***
88.30***
1004.11***
589.81***
1020.90***
Monolingual
Vs Bilingual
11.21**
5.98*
1.48
45.60***
29.92***
APD
ME
PS
OR
CLAPT
(APD = Attention, Perception and Discrimination,
ME = memory, PS = Problem solving, OR= organization,
* = significant at 0.05 level, ** = significant at 0.01 level,
*** = significant at 0.001 level).
bilingual group.
Comparison between monolingual healthy elderly
and monolingual persons with dementia:
A MANOVA was conducted for examining the
associations between the groups (Monolingual HE
and Monolingual PWD) over the dependent variables
or subtests of CLAP (APD, ME,. PS, OR and CLAPT).
The results indicated a significant difference for all
the subtests of CLAP viz attention, perception &
discrimination ( F (1,38) = 97.93; p = 0.001) , memory
( F (1,38) = 293.821; p = 0.001), problem solving( F
(1,38) = 1377.58; p = 0.001), and organization skills
( F (1,38) = 237.129; p = 0.001) indicating a strong
category effect between the groups at p< 0.001 level.
To cross check the findings of MANOVA, a MannWhitney test (non-parametric) was used because
of the dissimilarity in the sample size. The results
indicated a highly significant difference between the
groups (HE and PWD) for all the subtests of CLAP
viz Attention, Perception & discrimination (z = -4.68;
p <0.001), memory (z = -4.70; p <0.001), problem
solving (z = -4.73; p <0.001), and organization skills
(z = -4.69; p <0.001) at p<0.001 level.
Comparison between bilingual healthy elderly and
bilingual persons with dementia:
A MANOVA carried out for examining the
associations between the bilingual groups (HE and
PWD) over the dependent variables (subtests of
CLAP). The results indicated a significant difference
for all the subtests of CLAP viz Attention, Perception &
discrimination ( F (1,38) = 423.96; p = 0.001), Memory
( F (1,38) = 155.75; p = 0.001), problem solving( F
(1,38) = 460.73; p = 0.001), and organization skills
( F (1,38) = 492.796; p = 0.001) indicating a strong
105
JISHA 25 (2), 98-112
Discourse in Dementia
category effect between the bilingual participants
at p< 0.001 level. Similarly Mann Whitney test was
administered to bilingual healthy elderly and bilingual
persons with dementia. The result of Mann Whitney
test administered between bilingual persons with
dementia and bilingual healthy elderly to check the
effect of group for APD (z= -4.86, p < 0.001), ME (z=
-4.48, p < 0.001), PS (z= -4.878, p < 0.001), OR (z=
-4.73, p < 0.001) and CLAPT (z= -4.69, p < 0.001). As
seen from table 4 there was significant effect of group
for all the five parameters at p<0.001.
The comparison between healthy elderly and PWD
in both the categories (monolingual and bilingual)
indicated that there was significant difference
between the groups in their performance on CLAP
(the p values are mentioned in the text in page 13 and
14). This suggests that the decline in the cognitive
skills such as memory, attention and perception,
problem solving etc begins at the early stage of
dementia. This finding is in consensus with Perry and
Hodges (1999) study. Though necessary adaptation
like bigger letters and longer duration were made
for participants in the clinical group in the visual
attention task the performance was still inaccurate
and poor. The result indicates that disease related
changes in this population result in several perceptual
disadvantages. Results from CLAP also indicate
that participants in clinical group were slower and
inaccurate in performing attention, perception and
discrimination tasks. They exhibited impairment in
the ability to learn and remember new information
but relatively preserved recognition and increased
performance with cueing. Persons with mild dementia
showed a reduced attention span and were sensitive
to word length. That is, they had difficulty in attending
to lengthy instructions. Significant decrement in
a task that assessed the attention component of
working memory was observed in these populations.
They showed diminished scores on tests of attention
perception and discrimination result primarily from
attenuated span capacity, difficulty focusing attention
and encoding the information. When multiple
and competing demands for attention exceeded
it was difficult for them to concentrate on the task.
Task related to organization and problem solving
requires attention ability and intact working memory.
It was observed that these skills were impaired in
persons with dementia which resulted in inaccurate
performance. These arguments are in agreement with
the findings by Baddeley (2001) and Foldi, Loosco
and Schaefer (2002).
Results from the CLAP indicate that the persons
with dementia exhibited the decline in the cognitive
skills such as memory, attention, organization and
problem solving. Problems related to memory processes
are particularly vulnerable to the effects of dementia
which are due to failure in executive control system.
There is evidence of reduced memory span and short
term memory (STM) capacity in dementia (Morris, 1986).
Comparison between monolingual and bilingual
persons with dementia:
Once the two way MANOVA with respect to group
showed statistical difference, it was ideal to analyze
monolingual versus bilingual PWD in the performance
on CLAP. Monolingual PWD and bilingual PWD
were compared using one-way MANOVA, to check
the interaction between the categories. The results
of the one way MANOVA between the category for
the groups with PWD suggest that there was highly
significant difference for the parameters, APD (F(1,58)
= 2.09; p<0.001) , ME (F(1,58) = 2.95; p<0.001), PS
(F(1,58) = 20.18; p<0.001), and OR (F(1,58) = 234.74;
p<0.001) except for CLAPT at p<0.001 level. That is,
the overall total did not show difference between the
groups but the subtests of CLAP showed significant
difference at p<0-001 level.
In case of monolingual PWD versus bilingual
PWD the overall cognitive-linguistic decline was
statistically significant. But, the skills which required
higher cognitive functioning, such as PS, OR showed
differences between the groups. APD and ME did not
differ between the groups suggesting that the bilingual
PWD can person better than their counter group
in cognitively difficult tasks. And it is observed that
monolinguals can compete with bilingual PWD in tasks
involving minimal cognitive efforts. A less complete
or elaborate mental representation would thus be
available to higher cognitive process such as problem
solving skills. Bilingual persons had advantage of
dual languages and hence they were able to perform
better than their monolingual counterpart. This also
helps in reducing the progression of the disease
(Bialystok, Craik, & Freedman, 2007; Salvatierra &
Roselli, 2011)
Though the study was primarily based on discourse
analyses, cognitive linguistic testing was included
because it is a known fact that cognitive slowing in
dementia influences their ability to use language
in social situation. We tried to correlate between
performances in cognitive linguistic testing as
against their performances in generative discourse
production.
T-unit based analysis
The discourse samples were transcribed verbatim
before subjecting to analysis. After the completion of
transcription, the discourse samples were divided into
clauses and t-units. Number of clauses and t-units
were calculated manually. These calculated values
were grouped under different parameters such as,
106
JISHA 25 (2), 98-112
Discourse in Dementia
number of clauses (NOC), number of T-units (NOTU),
number of words per clause (NOWPC), number of
words per T-unit (NOWPTU), number of irrelevant
clause (NOIRC), and number of incomplete clause
(NOIC). The scores were tabulated and analyzed
using SPSS 16 (Statistical Package for Social
Sciences).
Descriptive statistics was performed to check for
the overall performance between healthy elderly
and PWD in both monolinguals and bilinguals. The
table 5 depicts the mean and standard deviation for
parameters of t-unit based analysis. It summarizes
and compares the sentence level characteristics of
the narrative discourses produced by the subjects. A
two way MANOVA and Duncan test was carried out to
investigate the effect of group and category.
Comparison between the normal group and
clinical group
Table 6 summarizes the results of two way MANOVA
and as it is seen from the table, there was statistically
significant difference between persons with dementia
and healthy elderly in the number of embeddings.
Embeddings here means the number of noun and
verb phrases. There was quantitative reduction in
the amount and complexity of language produced by
the participants from clinical group relative to healthy
elderly group, primarily because the persons with
dementia used less embeddings in their
Table 5. Results of descriptive statistics for t-unit based analysis for healthy elderly and persons with
dementia.
Healthy Elderly
Mean
PD
NOC
CON
PD
NOTU
CON
PD
NOWPC
CON
PD
NOWPTU
CON
NOIC
SD
N
Mean
SD
N
M
36.60
2.11
30
20.50
1.71
10
B
45.70
1.05
30
27.00
1.56
10
M
36.60
2.11
30
20.50
1.71
10
B
45.70
1.05
30
27.00
1.56
10
M
33.40
1.77
30
17.30
1.33
10
B
33.70
1.88
30
23.30
2.45
10
M
33.40
1.77
30
17.30
1.33
10
B
33.70
1.88
30
23.30
2.45
10
M
5.80
.78
30
2.70
.82
10
B
5.30
.67
30
4.40
1.50
10
M
5.80
.78
30
2.70
.82
10
B
5.30
.67
30
4.40
1.50
10
M
12.30
1.56
30
4.80
.91
10
B
11.70
1.63
30
6.40
1.83
10
M
12.30
1.56
30
4.80
.91
10
11.70
1.63
30
6.40
1.83
10
M
.00
.00
30
3.90
.87
10
B
.00
.00
30
3.60
.51
10
M
.00
.00
30
3.90
.87
10
B
.00
.00
30
3.60
.51
10
PD
M
.20
.42
30
8.00
.81
10
B
.10
.31
30
7.20
1.47
10
CON
M
.20
.42
30
8.00
.81
10
B
.10
.31
30
7.20
1.47
10
PD
NOIRC
Dementia
CON
(NOC = number of clauses, NOTU= number of T-units, NOWPC = number of words per clause, NOWPTU = number of
words per T-unit, NOIRC = number of irrelevant clause, NOIC = number of incomplete clause, PD = Picture Description,
CON = Conversation)
107
JISHA 25 (2), 98-112
Discourse in Dementia
Table 6. Results of two way MANOVA for t-unit based analysis for healthy elderly and persons with dementia.
Source
Picture Description
Dependent Variable
Conversation
F(1,36)
Dependent Variable
F(1,36)
Healthy
NOC
1.10***
NOC
55.49***
elderly
NOTU
483.56***
NOTU
6.60**
NOWPC
39.77***
NOWPC
46.27***
NOWPTU
175.12***
NOWPTU
56.52***
Persons With
NOIRC
544.35***
NOIRC
13.80***
Dementia
NOIC
711.06***
NOIC
.10
Monolingual
NOC
221.23***
NOC
203.30***
Vs
NOTU
27.33***
NOTU
243.86***
NOWPC
3.58
NOWPC
110.08***
NOWPTU
1.06
NOWPTU
254.39***
NOIRC
.87
NOIRC
1139.50***
NOIC
2.59
NOIC
154.67***
Vs
bilingual
(NOC =
number of clauses,
NOTU= number of T-units, NOWPC =
number of words per clause,
NOWPTU = number of words per T-unit, NOIRC = number of irrelevant clause, NOIC = number of incomplete clause,
* = significant at 0.05 level, ** = significant at 0.01 level, *** = significant at 0.001 level).
sentences than healthy elderly. This was true both for
picture description as well as conversation tasks at
p<0.001 level. Both the picture description as well as
conversation taps the ability of cognition in relation to
language in use. This seems to be reduced in PWD.
As a result, the discourse produced by PWD remains
sub averaged. PWD performed lesser than healthy
elderly on all the cognitive related tasks in CLAP. It
is well known that discourse is the integrated product
of attention, memory, and organization. So the poor
performance in these tasks by PWD has resulted in
reduced quality of generative discourse production.
Table 7. Results of Duncan test for t-unit bases analysis
for healthy elderly and persons with dementia.
Group/
Healthy
elderly
Vs
Persons
with
Dementia
Parameters
Picture
Conversation
Description
F(3,36)
F(3,36)
NOC
442.77***
442.77***
NOTU
177.75***
177.75***
NOWPC
18.46***
18.46***
NOWPTU
60.45***
60.45***
NOIRC
182.03***
182.03***
NOIC
238.40***
238.40***
(NOC = number of clauses, NOTU= number of T-units,
NOWPC = number of words per clause, NOWPTU
= number of words per T-unit, NOIRC = number of
irrelevant clause, NOIC = number of incomplete
clause, * = significant at 0.05 level, ** = significant at
0.01 level, *** = significant at 0.001 level).
This is in agreement with Beaugrande (2001) who
explained that reduced performance in language use
(discourse) reflects the decline in cognitive capacity
in these individuals.
Comparison between the categories
Duncan test was administered to check the effect of
group for t-unit based analysis on picture description
and conversation task. According to table 7 there
was significant difference between healthy elderly
monolingual and bilinguals for number of clauses.
The same was true between healthy elderly and
persons with dementia. Also there was statistically
significant difference between monolingual and
bilingual persons with dementia at p <.001 level.
For the number of t-units in the picture description,
there was significant difference between monolingual
and bilingual persons with dementia. Whereas,
there was no difference between the groups with
monolingual and bilingual healthy elderly. That is, the
groups did not differ for number of t-units. Also there
was significant difference between healthy elderly
and persons with dementia for the number of t-units
in picture description. In case of mean number of
words per clause for picture description, there was
no significant difference between the monolingual
and bilingual healthy elderly for number of words
per clause. But the difference existed between
monolingual and bilingual persons with dementia as
well as between healthy elderly and persons with
dementia for picture description at p <0.001 level.
Similarly in the number of words per t-unit for picture
description, there was no significant difference
108
JISHA 25 (2), 98-112
Discourse in Dementia
between monolingual and bilingual healthy elderly
for number of words per clause. But the difference
existed between monolingual and bilingual persons
with dementia as well as between healthy elderly and
persons with dementia for picture description as well
as conversation at p <0.001 level.
There was a significant difference between the
groups of persons with dementia for the number
of irrelevant clauses for picture description and
conversation at p<0.001 level. Also, the number of
irrelevant clauses was greater in monolingual persons
with dementia as compared with that of bilingual
persons with dementia. The numbers of incomplete
clauses were less in healthy elderly and there was no
difference between monolingual and bilinguals for the
same on picture description as well as conversation.
Monolingual and bilingual persons with dementia
did not differ in the number of incomplete clauses.
There was a significant difference between healthy
elderly as well as persons with dementia at p<0.001
level of significance. Based on the results of Duncan
test for t-unit based analysis on conversation there
was a significant difference between healthy elderly
monolingual and bilinguals for number of clauses.
The same was true between healthy elderly and
persons with dementia. But there was no statistically
significant difference between monolingual and
bilingual persons with dementia at p <.001 level.
It is observed from the study that, bilinguals
performed better in all the domains of cognitive
linguistic tasks as compared to monolinguals. This
might be because that a bilingual can compensate
for the word finding difficulty using the knowledge of
other languages. Whereas monolinguals have single
language in use and hence if they are unable to
use a particular word for a context The findings are
in agreement with Morris (1996) and Perry, Watson
& Hodges (2000) who found difficulty in focused
attention, and memory (forgetting the location of
objects) with the memory problems decreasing the
working memory capacity. But bilinguals can code
switch and complete that particular task. In the
present study, researchers were not interested in
studying the performance in a particular language, but
performance as a whole in cognitive linguistic task.
So the response either from native language (L1) or
the second language (L2) was taken as appropriate.
Hence bilinguals performed better as compared to
monolinguals.
In linguistic measures each patient individual
showed varied deviation from that of healthy elderly.
There were contrasts in terms of embedded structures,
number of clauses and t-units. Conversation is the
only task to show a lesser difference in the mean
scores of patient individuals. This is because all
subjects narrated information based on their long
term memory whereas the effect of damage was
evident in language discourse which was dependent
on recent/short term memories.
It appeared that discourse production is more
cognitively demanding. The older PWD had more
difficulty with word and utterance formulation. This is
reflected in their poor scores in t-unit based analysis.
Lack of statistically significant difference in healthy
elderly suggests that there is no significant changes
in spoken discourse performance of normal aging
adults. In case of PWD there was a relation between
discourse and cognitive flexibility. That is, the poor
performance in cognitive linguistic tasks by PWD
would have led to poor performance in discourse
related tasks. This is in agreement with Ylvisaker
& Szekeres (1989). But these findings should be
supported with other replicated studies. Additionally
discourse variables measured may not be those
directly related to cognitive flexibility. Also relation
between dementia, spoken discourse and cognitive
flexibility warrants further exploration.
While analyzing t-unit based parameters, it was
observed that PWD had difficulty with pronouns, i.e.,
they overused pronouns (Eg. /avnu/, /avLu/, /adu/, /
idu/ etc). This reflected the word finding difficulty in
them. They are not sensitive to incorrect pronouns
being used in discourse. Planning, organisation
and cognitive flexibility are important components of
executive functions (Crauford, 1998; Godefroy, 2003)
and they have been shown to influence discourse
production in brain damaged individuals (Coelho,
Liles & Duffy, 1998). However, it is beyond the scope
of the present study to determine specifically how
executive function will influence the discourse or
word retrieving abilities. The persons with dementia
present a particularly interesting case for the study
of the relation of linguistic functions to the integrity of
the mind and the dependencies between the different
types of linguistic knowledge.
Although, the healthy elderly adults used more
words, there was no difference between the groups
in terms of syntactic complexity. Syntactic complexity
in persons with dementia appears relatively spared in
milder stage (Cummings, 2000). Such complexity in
speech challenges the act of detecting decrements
in communicative ability. Hence to a casual listener,
decreased length of output and sparseness of
thematic detail may be misunderstood as structurally
complete sentence pattern. This supports previous
studies that phonological and syntactic abilities are
spared in early dementia (Bayles, 1982; Bayles,
Kaszniak & Tomoeda, 1987). Although this study did
not compare the syntactic complexity between the
groups, the length of discourse indirectly accounts
for the same. There was no difference between the
groups studied in the length of discourse produced.
109
JISHA 25 (2), 98-112
Discourse in Dementia
The results of this study reveal that bilinguals
performed better than their monolingual counter
group. This may be because bilinguals have more
linguistic resources as bilinguals could switch between
the languages. These findings are in agreement with
Ardila and Ramos (2010). To better understand the
discourse abilities in bilingual dementia, each of the
languages should be assessed separately (Mendez
& Perryman, 1999).
Conclusions
In conclusion, complex discourse production
analysis distinguishes persons with typical cognitive
aging from those persons with dementia. The
significant differences in the performance of persons
with dementia and healthy elderly participants in the
study are demonstrated using t-unit based analysis. In
the study, all the measures were sentence-frequency
dependent and can therefore be advantageously
combined to yield a final index of performance. Also
this study has identified the relative importance of
linguistic variables in discriminating persons with
dementia from healthy elderly. The outcome thus
contributes to the knowledge of changes in persons
with mild dementia by providing a database consisting
of empirical data regarding subtle cognitive-linguistic
changes in them. Further work however, is necessary
to explore specific type of deficits among various
types of dementia using other methods of discourse
analysis. Also discourse, specific to each language
known to the individuals may be assessed separately.
This study is one of the first step at differentiating
between persons with dementia and healthy elderly
using linguistic measures alone. However, input from
different professionals/ multidisciplinary team needs
to be taken into consideration for differentiation and
assessment of dementia.
Address for correspondence:
Deepa M.S.,
Junior Research Fellow, Dept. of Speech-Language
Pathology, All India Institute of Speech and
Hearing, University of Mysore, Mysore-6. E-mail ID:
[email protected]
References
Allen, F. (2000) Diagnostic and Statistical Manual
of Mental Disorders (DSM-IV-TR). 4th ed.
Washington,
DC:
American
Psychiatric
Association.
Alma, A. U., Agnes, S., Chan., & Chiu. - (2003).
Verbal learning in Alzheimer’s dementia. Journal
of the International Neuropsychological Society, 9,
363-375.
Alzheimer’s Association (2011). Education and
Awareness: stages of dementia. Retrieved from
www.alz.org.
American Psychiatric Association (1994). Diagnostic
and statistical manual of mental disorders (4th
ed.). Washington, DC: Author.
American Psychiatric Association (2000). Diagnostic
and statistical manual of mental disorders, (4th
ed., text version). Washington, DC: American
Psychiatric Association.
Ardilla, A., & Ramos, A. (2010). Bilingualism and
Aging. Perspectives on Communication Disorders
and Sciences in Culturally and Linguistically
Diverse Populations, 17, 74-81.
Ash, S., Moore, P., Antani, S., McCawley, G., Work,
M., & Grossman, M. (2006). Trying to tell a tale:
discourse impairments in progressive aphasia
and frontotemporal dementia. Neurology, 66(9),
1405-13.
Baker, C. (1996). The development of bilingualism,
Foundations of Bilingual Education and
Bilingualism (2nd Ed.). Clevedon: Multilingual
Matters.
Bayles, K. A. (1982). Language functions in senile
dementia. Brain and Language, 16, 265-280.
Bayles, K. A., Kaszniak, A. W., & Tomoeda, C. K.
(1987). Communication and Cognition in Normal
Aging and Dementia. Boston, MA, USA: CollegeHill Press.
Beaugrande, R. (2001). Interpreting the discourse of
H.G. Widdowson: A corpusbased critical discourse
analysis. Applied Linguistics. 22(1), 104-21.
Bialystok, E., Craik, F. I., & Freedman, M. (2007).
Bilingualism as a protection against the onset of
symptoms of dementia. Neuropsychologia, 45(2),
459-464.
Bialystok, E., Craik, F. i. M., & Freedman, M. (2007).
Bilingualism as a protection against the onset of
symptoms of dementia. Neuropsychologia, 45,
459-464.
Brownell, H. H., & Joanette, Y. (1993). Narrative
discourse in neurologically impaired and normal
aging adults. San Diego, CA: Singular Publishing
Group.
Bucks, R. S., Singh, S., Cuerden, J. M., & Wilcock, G.
K. (2000). Analysis of spontaneous, conversational
speech in dementia of Alzheimer’s type: Evaluation
110
JISHA 25 (2), 98-112
Discourse in Dementia
of an objective technique for analysing lexical
performance. Aphasiology, 14(1), 71-91.
Calderon, J. R., Perry, S., & Hodges, J. (2001).
Perception, attention, and working memory
are disproportionately impaired in dementia
with Lewy bodies compared with Alzheimer’s
disease. Journal of Neurology, Neurosurgery and
Psychiatry, 70(2), 157–164.
Hunt, K. (1965). Grammatical structures written at
three grade levels. NCTE Research report No. 3.
Champaign, IL, USA: NCTE
Hyltenstam, K., & Obler, L. K. (1989). Bilinguals across
the lifespan: Aspects of Acquisition, Maturity and
Loss. New York: Cambridge University Press.
Castello, F.G., Brandio, L., Teun, A., Parente,
M.A., Caranova, J. (2009). Cognition and
discourse production in Alzheimer’s Dementia:
using informative prompts. Psychology and
Neuroscience, 2(2), 147 – 155.
Jhoo, J. H., Kim, K.W. Huh, Y., Lee, S. B., Park, J.
H.,Lee, J. J., Choi, E. A., Han, C. Choo, H. Jong, C.
Y (2008). Prevalence of dementia and its subtypes
in an elderly urban korean population: results from
the Korean Longitudinal Study on Health And
Aging (KLoSHA). Dementia and Geriatric Cognitive
Disorders, 26(3):270-6.
Coelho, C. A., Liles, B. Z., & Duffy, R. J. (1995).
Impairments of discourse abilities and executive
functions in traumatically brain-injured adults.
Brain Injury, 9(5), 471- 477.
Kamath, A., & Pream, K. S. (2001). Cognitive linguistic
assessment protocol for adults. Unpublished
Masters dissertation, University of Mysore,
Mysore.
Crawford, J. R. (1998). Introduction to the
assessment of attention and executive functioning.
Neuropsychological Rehabilitation, 8(3), 209–211.
Karen, L., Mozeiko, J., & Coelho, C. (2011). Discourse
analysis: characterizing cognitive-communication
disorders following TBI. The American Speech
and Hearing Association LEADER. Retrieved
online from www.asha.org.
Cummings, J. L. (2000). Cognitive and behavioural
heterogeneity in Alzheimer’s disease: Seeking the
neurobiological basis. Neurobiological Ageing,
21(6), 845–861.
Deepa M. S., & Sudheer, B. (2007). Narrative
discourse analysis in mild cognitive impairment
and early Alzheimer’s disease. Unpublished
Master’s Dissertation, Osmania University,
Hyderabad.
Folstein, M. F., Folstein, S. E., & McHugh, P. R.
(1975). Mini-Mental state. A practical method
for grading the cognitive state of patients for the
clinical. Journal of Psychiatric Research, 12,
189-198.
Godefroy, O. (2003). Frontal syndrome and disorders
of executive functions. Journal of Neurology,
250(1), 1–6.
Hoppe, C., Werheid, K., Thone, A., Muller, U.,
Mungersdorf, M., & Cramon, Y. V. (2002). The
Adaptive Digit Ordering Test: Clinical application,
reliability, and validity of a verbal working memory
test. Achieves of Clinical Neuropsychology, 17(6),
547-565.
Hughes C. P., Berg, L., Danziger, W. L., Coben, L. A.,
& Martin, R. L. (1982). A new clinical scale for the
staging of dementia. British Journal of Psychiatry,
140, 566-572.
Krishnan, G., & Lokesh, H. (2010). Addenbrrokes
Cognitive examination revised in Kannada.
Submitted to Annals of Neurology.
Linell, P. (1998). Approaching Dialogue: Talk,
interaction and contexts in dialogical perspectives.
Amsterdam: John Benjamins.
McMurtray A,. Saito E., & Nakamoto B. (2009).
Language preference and development of
dementia among bilingual individuals. Hawaii
Medical Journal, 68(9), 223-6.
Mendez M. F., & Cummings, J. L. (2003). Dementia:
a clinical approach, third edition. Philadelphia, PA:
Elsevier Science Publishing Company.
Morris J. C. (1993). The Clinical Dementia Rating
(CDR): Current version and scoring rules.
Neurology, 43, 2412-2414.
Morris, R. G. (1994). Working memory in Alzheimer’s
type dementia. Neuropsychology, 8(4), 544-554.
Morris, R.G. (1996). The cognitive neuropsychology
of. Alzheimer-type dementia. Oxford: Oxford
University Press.
Parasuraman, R., Greenwood, P. M., Haxby, J. V.,
& Grady, C. L. (1992). Visuospatial Attention in
Dementia of the Alzheimer Type. Brain, 115(3),
711-733.
111
JISHA 25 (2), 98-112
Discourse in Dementia
Perry, R., Watson, P., & Hodges, J. (2000). The
nature and staging of attention dysfunction in
early (minimal and mild) Alzheimer’s disease:
Relationship to episodic and semantic memory
impairment. Neuropsychologia, 38, 252-271.
Perry, R.J. & Hodges, J.R. (1999). Attentional and
executive deficits in dementia of Alzheimer’s
type. Journal of Neurology, Neurosurgery and
Psychiatry, 57, 416–418.
Rabadan, O. (1994). The assessment of bilingualism
in normal aging with the bilingual aphasia test.
Journal of Neurolinguistics, 8(1), 67-73.
Rajasudhakar, S., & Shyamala, K. C. (2008). A
study of the effect of age, gender and lingualism
on cognitive-linguistic performance. Students
Research at All India Institute of Speech and
Hearing, Mysore, 3, 127-146.
Salvatierra, J. L., & Roselli, M. (2011). The effect
of bilingualism and age on inhibitory control.
International Journal of Bilingualism, 15(1), 26-37.
Silveri, M. C., Reali, G., Jenner, C., & Puopolo M
(2007). Risk factors for transitions from normal to
mild cognitive impairment and dementia. Journal
of Geriatric Psychiatry Neurology, 20(2), 67 - 75.
Virtanen, T. (2004). Approaches to Cognition through
Text and Discourse. Berlin: Mouton de Gruyter.
Wylie, E., & Ingram, D. E. (2006). International
Second Language Proficiency Ratings (ISLPR)
general proficiency version for English Nathan,
Qld: Centre for Applied Linguistics and Language,
Mt Gravatt Campus Griffith University.
Ylvisaker, M., & Szekeres, S. F. (1989). Metacognitive
and executive impairments in head-injured children
and adults. Topics in Language Disorders, 9(2),
34–49.
112