Language and Cognition
Colombo June 2011
Day 10 Dementia
Definitions
• ‘Dementia is the general term given to
neuropsychological syndromes characterised by
acquired cognitive impairment in multiple spheres but
without impaired consciousness’ (Brandt and Rich 1995)
• ‘The development of multiple cognitive deficits, including
memory impairment and at least one of the following
cognitive disturbances – aphasia, apraxia, agnosia or a
disturbance of executive functioning’ (The American
Psychiatric Association 1994)
Prevalence
• 15% of the population over 65: some form of
dementia (Cummings and Benson 1992).
• 47% of people over 85 affected (Evans et al 1989)
• Alzheimer’s Disease (AD) is the largest single
cause of dementia
• Other causes:
– Multi Infarct Dementia, Parkinson’s disease, Pick’s
disease, Huntingdon’s Chorea and CreutzfeldtJacobs Disease.
Neurobiological changes in
Alzheimer’s Disease
• Morris and Worsley 2003:
• Gross atrophy with widening sulci and ventricular
enlargement; the frontoparietal region and temporal
lobes are most affected
• Widely distributed senile or neuritic plaques in the cortex,
hippocampus and some sub-cortical structures
• Neurofibrillary tangles; affecting most areas but
particularly in the hippocampus, amygdala and
parahipppocampal gyri.
• These changes can only be identified definitively at
autopsy. Therefore only probable AD can be diagnosed
during the person’s lifetime.
• Significant variation in symptoms between people
Clinical Signs of Dementia of Alzheimer’s
Type (DAT)
Early Stage
Mild forgetfulness
Misplaced objects
Some disorientation in
unfamiliar places
Anomia for proper &
low freq vocabulary
Circumlocution
Repetitive discourse
Affect changes
Anxiety and depression
Mid Stage
Hazardous everyday
memory problems
Disorientation in
familiar places
Visuo spatial deficits
Severe word finding
problems with semantic
errors
Poor comprehension
Difficulties with
complex sentences
Apathy & sleep
disturbance
Late Stage
Severe memory
problems
Poor recognition of
familiar people
Wandering
Bizarre behaviours
Little/no spontaneous
speech
Very poor
comprehension
Echolalia
Stereotyped utterances
Primitive reflexes
Incontinence
Dysphagia
Word finding in DAT:
Evidence of Semantic Impairment
Hodges et al (1992)
• Significant relationship between naming and
comprehension – items that induced naming failures also
induced comprehension failure
• Grosser tasks, like sorting into unrelated categories,
were preserved
Are all naming problems semantic?
Mary (Funnell 1992)
• 2 year history of DAT
• Memory impairment
• Visuo spatial difficulties
• Dyscalculia
• Severe anomia even with high frequency words
(9/30 on Graded Naming Test)
Initial Comprehension Testing
•Word to picture matching
–(BVPS; PALPA)
•Semantic questions
–(‘does a rabbit have fur?’)
99%
100%
Demonstrates understanding of low frequency words like
‘bovine’ and ‘prestigious’
Impairment in accessing lexical phonologies
2 years later: Rapid decline on comprehension and
semantic tasks
Word to picture matching over time
45
40
35
30
25
20
15
10
5
0
Correct
Semantic errors
Unrelated
1
2
3
4
5
6
Syntax in DAT
• Syntactic skills often better preserved than
semantic
• Speech still displays syntactic structure, at least
in the early stages
– ‘The picture incorporates a certain amount of coming
and going and cheating and doing the things in the
world’ (Kempler 1995)
• Relative success on syntactic tasks
HCEM (Whitaker 1976)
• Age 59
• Familial dementia
• Diffuse atrophy (frontal and temporal lobes) and
ventricular dilation
• Living in nursing home
• Supported in all aspects of self care
• Disoriented for time, place and person
• Wandering behaviour
• ‘indolent, apathetic and totally non-communicative’
HCEM (Whitaker 1976)
Naming
• Virtually impossible
• Some semantic errors
Comprehension
• Untestable on single word, sentence level and non verbal tasks
• Unable to carry out requests (such as removal of chewing gum)
Repetition
• Almost all output is echolalia
HW
Do you like coffee?
HCEM
Do you like coffee?
HCEM (Whitaker 1976)
Syntax
Demonstrated through repetition task
• HW
• HCEM
Can you told the time?
Can you tell the time?
• HW
• HCEM
She likes eat
She likes to eat
• HW
• HCEM
There are two book on the table
There are few books on the table
Writing in DAT
• Writing to dictation may be relatively well
preserved
• Surface dysgraphia as semantic/lexical
routes failing
–Regular words > Irregular words
Argues for sublexical, PGC writing
Note that patterns are variable and can
show phonological dysgraphia or
combination (Luzzatti et al 2003)
Speech
Pictures/Objects
Auditory
Analysis
Picture
Analysis
AIL
Picture
Recognition
Writing
Visual
Analysis
VIL
GPC
Semantics
POL
Buffer
Speech
OOL
PGC
Buffer
Writing
The role of executive control:
Funnell and Hodges 1996
•
•
•
•
•
MCR
Farmer’s wife
2 year history of deteriorating speech and memory
‘My mind goes blank when I’m doing things’
Family report everyday memory problems (forgetting
tasks and messages)
• Speech increasingly sparse, with unfinished sentences
MCR: Funnell and Hodges 1996
Impaired on executive tasks
• Card Sorting
• Stroop task
Card Sorting












Task: sort by one criteria (colour); then switch to a
different criteria (symbol)
Problem: continued to sort by first criteria, even
when given very explicit feedback by tester
Stroop Task
RED
• Read word (good)
• Name colour (very poor)
Interim Conclusions
• MCR shows evidence of executive impairment
• Does this underpin her poor word finding?
Language Testing
Good performance on:
• Word to picture matching
• Semantic verification
– Is a salmon a tree (category)
– Does a mouse have a beak (feature)
• Picture naming (51/55)
Category Naming
• Named significantly less than controls
• Big discrepancy between (near normal) picture
naming and impaired category naming
• Responsive to semantic prompts
• Therefore: impaired ability to initiate/generate
ideas
Conclusions
• MCR shows relatively intact semantic processing
• MCR has an executive impairment
• Her language difficulties relate to this, she cannot
sustain plans, eg to generate a large number of items in
category naming
• Tasks that impose minimal executive demands (such as
picture naming) are still relatively intact
Focal Degenerative Diseases
Progressive language impairment as in DAT but:
• Intact day to day memory – live independently
until late in disease
• Good non verbal problem solving (Ravens
matrices)
• Good visuo-spatial abilities
– Can navigate round familiar environments
– Can do visual tasks like copying pictures
Focal Degenerative Diseases
Progressive Non Fluent
Aphasia
• Non fluent speech
• Dyspraxia
• Poor word finding with
effortful word search
• Phonological errors
• Good comprehension
• Impaired syntax
Semantic Dementia
• Fluent speech
• Normal articulation
• Empty speech lacking
content words
• No effortful word
searches
• Semantic errors (not
phon.)
• Impaired lexical
comprehension
• Retained syntax
Focal Degenerative Diseases
• Different patterns of impairment reflect different
regions of damage
– Non fluent progressive aphasia damage to
perisylvian language regions of left
hemisphere
– SD progressive damage to anterior temporal
lobes
Speech in Semantic Dementia (Garrard
and Hodges 1999)
‘Oh gosh, this seems to be, oh come on try to
remember the name: I know what they are
‘cause there’s three of these, so it not the two
and three. The one which er … some of them
will be in Britain because you know with our stuff
in Britain some of them are also outside Britain,
some of them are also in Britain as well. What
d’you call them again because N’s son no not
son brother he’s one of these as well’ (naming
soldier)
Fluent, syntactically structured, but few content
words
Naming in Semantic Dementia
• Within category substitutions (window/door)
• Overuse of superordinate substitutions (e.g.
“animal”)
• Frequent exemplar labels (eg all animals named
as ‘dog’)
• Item consistency, items failed in one test will be
failed in the next
Lexical Comprehension in Semantic
Dementia
•
•
•
•
•
Impaired performance
Initially close semantic errors
Later deny knowledge of word
Item consistency
May show category effects
Reading and Repetition in Semantic
Dementia
• Typically surface dyslexia
• Poor comprehension of written words
• Good repetition and reading aloud
• Performance reflects impaired central semantics
with better performance on peripheral language
tasks
Speech
Pictures/Objects
Auditory
Analysis
Picture
Analysis
AIL
Picture
Recognition
Writing
Visual
Analysis
VIL
GPC
Semantics
POL
Buffer
Speech
OOL
PGC
Buffer
Writing
Non verbal abilities in Semantic
Dementia
Pictures
• Copying 
• Drawing from memory x
• Categorisation x
Episodic memory – striking preservation in SD (not in DAT)
• Recall events in life 
• Remember appointments 
• Rarely get lost in familiar surroundings
• Although early/long term memories may be impaired
(STM impaired in DAT)
Autobiographical Effects on Language
‘I help reverend Jones by putting the chalice
back in the vestry’
(Snowden et al 1994)
Is autobiographical experience (Episodic
Memory) sustaining vocabulary?
Further research by Snowden suggests yes.
Therapy?
DM (Graham et al 2001)
• Self initiated practice with vocabulary
– List words together with definitions
– Cover words and attempt to recall
Outcomes
• Practised words are named well (in fluency task)
• Control words are not named well
• When controls are practised naming improves
But ..
• Learnt categories are poorly maintained
• Learning is entirely rote (words are recalled in the same
order as the list in notebook)
• Learning is without understanding (able to name
‘dalmatian’ but has no idea what it is)
• Practice becomes obsessive and needs increasing input
in order to be maintained (7 – 8 hours per day)
See Heredia et al 2009 for a more recent example of
therapy
Practical Help (Snowden et al 2000)
• Sustain person in familiar environment for as
long as possible
• Help person sustain rich and varied life style
• Minimise opportunities for dangerous semantic
errors (no bleach in bathroom)
• Follow strict routine (familiar food packets will be
recognised, unfamiliar ones will not)
• Only train concepts within meaningful context
(example of lemon in gin and tonic)
• Use rehearsal to sustain concepts