Max Coltheart

1
Neuropsychological rehabilitation the
cognitivist approach
Max Coltheart Macquarie Centre for Cognitive
Science Macquarie University Sydney NSW Australia
2
Coltheart, M. Aphasia therapy research a single
case study approach. In Code, C., and Muller,
D.C. (Eds.), Aphasia Therapy. London Edward
Arnold, 1983.
3
Neuropsychological rehabilitation the
cognitivist approach
Characteristics of the cognitivist aproach It
is model-based It focusses on restoration
rather than compensation It is not the same
thing as cognitive rehabilitation It specifies
what to treat but has little to say about how to
treat it It emphasizes and confronts the
heterogeneity of disorders within a given
cognitive domain and the need for subtyping
4
The cognitivist approach is model-based
It begins with a model of the mental
information-processing system that people
normally use to carry out the cognitive activity
in question Such cognitive systems are thought
of as consisting of a number of
information-processing components, modules, each
responsible for carrying out part of the
cognitive processing that is needed Assessment
consists of determining which of these modules
are still functioning normally and which are
not Treatment is directed at those modules
which assessment has shown to be functioning
abnormally
5
The cognitivist approach focusses on restoration
rather than compensation
6
An ancient distinction Reorganization versus
restoration
7
An ancient distinction expressed with less
phonological confusability Compensation versus
restoration
8
Compensation This person is far below the
normal range of ability in some particular
cognitive domain (e.g. attention, memory,
language, or executive function) Can we find a
way in which to reduce or eliminate the impact of
this reduced ability on the persons life? Can
we, in WHO terms, do something so that this
disability will no longer be a handicap?
9
Restoration This person is far below the normal
range of ability in some particular cognitive
domain (e.g. attention, memory, language, or
executive function) Can we find a way in which
to improve this persons ability in the affected
cognitive domain so that the person no longer has
a disability in this cognitive domain?
10
An imaginary example prosopagnosia After his
stroke, this man can no longer recognise people
by their faces, not even his wife he may well
pass her by on the street, unknowingly. This
distresses him (and her). What to do?
Compensation Propose that she buy a very
distinctive pair of spectacles and always wear
them he can then use this as a cue for
identifying his wife Restoration Try to
improve the operation of his face recognition
system so that it can recognise faces again, at
least for faces that were highly familiar.
11
Restoration This person is far below the normal
range of ability in some particular cognitive
domain (e.g. attention, memory, language, or
executive function) Can we find a way in which
to improve this persons ability in the affected
cognitive domain so that the person no longer has
a disability in this cognitive domain?
The cognitivist approach focusses on restoration
12
The cognitivist approach is not the same thing as
cognitive rehabilitation
13
A definition of cognitive rehabilitation
A systematic functionally-oriented service of
therapeutic cognitive activities, based on an
assessment and understanding of the persons
brain-behavior deficits. Services are directed to
achieve functional changes by (1) reinforcing,
strengthening or reestablishing previously
learned patterns of behavior or (2) establishing
new patterns of cognitive activity or
compensatory mechanisms for impaired neurological
systems
(Official statement by the US National Academy of
Neuropsychology, May 2002)
14
A definition of cognitive rehabilitation
A systematic functionally-oriented service of
therapeutic cognitive activities, based on an
assessment and understanding of the persons
brain-behavior deficits. Services are directed to
achieve functional changes by (1) reinforcing,
strengthening or reestablishing previously
learned patterns of behavior or (2) establishing
new patterns of cognitive activity or
compensatory mechanisms for impaired neurological
systems
Differs from the cognitivist approach Not
model-based Applies only to acquired
disorders Does not focus specifically on
restoration
15
The cognitivist approach specifies what to treat
but has little to say about how to treat it
16
The cognitivist approach emphasizes and confronts
the heterogeneity of disorders within a given
cognitive domain and the need for subtyping
Language impairment Just spoken language
Just spoken language production
Just grammatical aspects (function
words affixes) Just
affixes
17
The cognitivist approach emphasizes and confronts
the heterogeneity of disorders within a given
cognitive domain and the need for subtyping
Developmental dyslexia is caused by impaired
auditory processing and auditory training will
remediate it (Tallal Merzenich -
http//www.fastforward.com ) Developmental
dyslexia is caused by cerebellar dysfunction and
programs of balance exercises will remediate it
(David Reynolds Wynford Dore -
http//www.ddat.co.uk ) Developmental dyslexia
is caused by a proclivity to think in pictures
and training in visual perception (Davis Dyslexia
Correction) will remediate it (Ron Davis -
http//www.dyslexia.com )
18
The cognitivist approach - an example (work in
progress by Ruth Brunsdon on treatment of
children with spelling difficulties)
19
Case MC 12-year-old boy FSIQ 112 Poor reading
and poor spelling
(Brunsdon, Nickels Coltheart, work in progress)
20
So first we need a model . . .
21
Some modules of the language-processing system
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
22
How do these modules communicate with each other?
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
23
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
24
A model of the single-word language processing
system for use in assessment.
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
25
Now we use the model for assessment . . .
26
Nonwords read well, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
27
Nonwords read well, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
28
Nonwords spelled to dictation well, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
29
Nonwords spelled to dictation well, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
30
Intact comprehension of spoken language, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
31
Intact comprehension of spoken language, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
32
Intact production of spoken language, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
33
Intact production of spoken language, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
34
Impaired visual lexical decision, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
35
Impaired visual lexical decision, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
36
Task reading aloud and defining written
irregular homophones
QUEUE PEAR THEIR STEAK
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Task reading aloud and defining written
irregular homophones
QUEUE v PEAR v THEIR v STEAK v
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Task reading aloud and defining written
irregular homophones
QUEUE v the actor needed a cue PEAR v socks -
pairs of them THEIR v there is the
ball STEAK v I stuck a stake in the ground
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queue -gt the actor needed a cue, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
40
queue -gt the actor needed a cue, so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
41
Task listen to a disambiguated homophone,
then write it to dictation
Bred . . . They bred cattle carefully Bare .
. . The desert landscape was bare Pair . . .
He wore a pair of black shoes Their . . . They
were washing their clothes
42
Task listen to a disambiguated homophone,
then write it to dictation
Bred . . . They bred cattle carefully -gt
bread Bare . . . The desert landscape was bare
-gt bear Pair . . . He wore a pair of black
shoes -gt pear Their . . . They were washing
their clothes -gt there
43
Task listen to a disambiguated homophone,
then write it to dictation
Bred . . . They bred cattle carefully -gt
bread Bare . . . The desert landscape was bare
-gt bear Pair . . . He wore a pair of black
shoes -gt pear Their . . . They were washing
their clothes -gt there Key point All of these
responses are irregularly-spelled words so these
errors are not coming from the use of
phoneme-grapheme rules. They are being generated
from the orthographic lexicon.
44
Bare . . . The desert landscape was bare -gt
bear so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
45
Bare . . . The desert landscape was bare -gt
bear so . . .
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
46
The complete assessment three impairments of
orthography
speech
print
VISUAL FEATURE ANALYSIS
GRAPHEME-PHONEME CONVERSION
ABSTRACT LETTER UNITS
PHONOLOGICAL BUFFER
ORTHOGRAPHIC LEXICON
PHONOLOGICAL LEXICON
SEMANTICS
PHONEME- GRAPHEME CONVERSION
GRAPHEMIC BUFFER
print
47
Now we think of some treatment method that might
build up to normality the poorly acquired
orthographic system . . .
48
222 irregular words chosen and divided into 3
equal sets For set 1

• MC shown a flash card with an irregular word on
  it.
• He copied the word.
• The word was taken away and he wrote it 10
  seconds later
• Then he wrote it to dictation
• His parents gave him practice at home in writing
  the words to dictation

Set 2 and set 3 words acted initially as controls
49
And we design the treatment regime so that we can
determine whether or not the treatment actually
works . . .
50
Firstly, pretest spelling of all words
100
90

80
70
60
50
40
30
20
10
0
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The three sets are equally difficult
100
90

80
70
60
50
40
30
20
10
0
52
Is there improvement over time without treatment?
Do a second baseline
100
90

80
70
60
50
40
30
20
10
0
53
Is there improvement over time without treatment?
No.
100
90

80
70
60
50
40
30
20
10
0
54
OK. Begin treatment - JUST SET 1 ITEMS
100
90

80
70
60
50
40
30
20
10
0
55
Set 1 (treated) items improve greatly.
100
90

80
70
60
50
40
30
20
10
0
56
Set 1 (treated) items improve greatly. SIGNIFICANT
IMPROVEMENT IN SETS 2 3
100
90

80
70
60
50
40
30
20
10
0
57
Stop treating set 1 items. Treat Set 2 items.
100
90

80
70
60
50
40
30
20
10
0
58
Set 2 (treated) items improve greatly. Set 3
(untreated) items improve further
100
90

80
70
60
50
40
30
20
10
0
59
Now treat Set 3 items
100
90

80
70
60
50
40
30
20
10
0
60
Set 3 items improve greatly
100
90

80
70
60
50
40
30
20
10
0
61
How long-lasting are these improvements? Stop all
treatment.
100
90

80
70
60
50
40
30
20
10
0
62
Two months later
100
90

80
70
60
50
40
30
20
10
0
63
Four months later
100
90

80
70
60
50
40
30
20
10
0
64
(No Transcript)
65
Trying to understand the generalization effect
Why do some of the words improve even before they
are treated? What is it about a word that
determines whether it will improve without
treatment or whether it wont?
66
Trying to understand the generalization effect
An untreated and originally misspelled word is
more likely to become correctly spellable before
being treated if It is high in frequency
or It has many orthographic neighbours or
The original wrong spelling was similar to the
correct spelling according to a measure of
orthographic similarity based on a particular
computational model of reading.
67
Trying to understand the generalization effect
An untreated and originally misspelled word is
more likely to become correctly spellable before
being treated if It is high in frequency
or It has many orthographic neighbours or
The original wrong spelling was similar to the
correct spelling according to a measure of
orthographic similarity based on a particular
computational model of reading.
Implications for treatment if you arent
treating all words, treat the ones with low
frequency or few neighbours or low similarity of
response to correct spelling.
68
Neuropsychological rehabilitation the
cognitivist approach
Contra-indications for use of the cognitivist
aproach There is no theoretical model for the
cognitive domain in question For example,
topographical orientation there is no cognitive
model explaining how we perform this everyday
task So a purely compensatory approach was
adopted by Davis, S.J.C. and Coltheart, M.
Rehabilitation of topographical disorientation
An experimental single case study.
Neuropsychological Rehabilitation, 1999, 9, 1-30.
69
Neuropsychological rehabilitation the
cognitivist approach
Contra-indications for use of the cognitivist
aproach There is no theoretical model for the
cognitive domain in question The impaired
cognitive ability appears to depend on a highly
localized and dedicated brain region, now
severely damaged i.e. there is little or no
plasticity Face recognition X Language v
Object recognition ?
70
Neuropsychological rehabilitation the
cognitivist approach
Characteristics of the cognitivist aproach It
is model-based It focusses on restoration
rather than compensation It is not the same
thing as cognitive rehabilitation It specifies
what to treat but has little to say about how to
treat it It emphasizes and confronts the
heterogeneity of disorders within a given
cognitive domain and the need for subtyping