Levels of breakdown in impaired word retrieval

1
Levels of breakdown in impaired word retrieval

• Associate Professor Lyndsey Nickels
• Macquarie Centre for Cognitive Science (MACCS)
• Macquarie University, Sydney.

2
4 people with word production impairments
NAME AGE DISORDER CORRECT PICTURE NAMING
ARTHUR 65 yrs Acquired aphasia 54
MARIE 8 yrs Developmental Language Impairment 65
CHRIS 47 yrs Acquired aphasia 25
BECCA 9 yrs Developmental Language Impairment 34
3
Cognitive Neuropsychology An Assumption

• Treatment will be maximally effective only when
  the direction of treatment is determined by
  precise knowledge of the individuals processing
  strengths and weaknesses.
• Analysis limited to surface symptoms will not
  enable one to construct effective treatments
  because such symptoms can arise in various ways.

4
Arthur(acquired aphasia)

• Spider -gt ant

5
Arthur (acquired aphasia)
Pocket -gt sleeve
6
Marie(developmental language impairment)
Pineapple -gt not apple juice, oh the fruit
with the funky hairdo
From Best, 2005
7
Chris (acquired aphasia)

• Submarine -gt /sup?b?n?n s?b?bri s?b m?rin/

8
Chris (acquired aphasia)
Elephant -gt /ef?l .. ef?lt?n ?lf?n?nt
?lf?n?nt ?lf?t?n ?lf?nt el?f?n ef?l?nt /
9
Becca(Developmental language impairment)

• Hospital -gt /h?st?b?l/

From Best 2005
10
Different error types in word retrieval

• Arthur Marie make semantic errors
• Arthur spider -gt ant
• Marie Pineapple -gt not apple juice,
• oh the fruit with the funky hairdo
• Chris Becca make phonological errors
• Chris Submarine -gt /sup?b?n?n s?b?bri
• s?b m?rin/
• Becca Hospital -gt / h?st?b?l /
• WHY do these different error types occur?

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Pic naming
Picture naming
tail
purrs
fur
Lexical semantics
barks
fins
pet
4-legs
Phonological output lexicon
f-i-sh
d-o-g
c-a-t
f
a
a
i
c
sh
c
t
Phonological output buffer
t
cat
12
How do semantic errors occur?
Arthur Spider -gt ant Marie Pineapple -gt
the fruit with the funky hairdo

• Semantic errors are most commonly attributed to
  semantic impairments .
• i.e. Impaired representation of word meanings

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spoken naming sem deficit threshold to phoneme
level
Picture naming (with semantic impairment)
tail
purrs
fur
Lexical semantics
barks
fins
pet
4-legs
d-o-g
d-o-g
c-a-t
Phonological output lexicon
f-i-sh
f
a
i
sh
c
Phonological output buffer
t
dog
14
spoken naming sem deficit threshold to phoneme
level
Semantic errors (without semantic impairment)
tail
purrs
fur
Lexical semantics
barks
fins
pet
4-legs
d-o-g
d-o-g
c-a-t
d-o-g
c-a-t
Phonological output lexicon
f-i-sh
f-i-sh
f
a
i
sh
c
Phonological output buffer
t
dog
15
Summary Semantic errors

• Two possible levels of impairment in spoken word
  production
• Semantic impairment
• Post semantic impairment
• Access to phonological representation (or loss of
  those representations)
• Semantic errors are a symptom which can have as
  their cause different underlying levels of
  impairment.
• How can we distinguish these different levels of
  impairment?

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How do we determine the underlying level of
impairment?

• - examine performance on other tasks that also
  use some of the processing components involved in
  word production.
• - if a person with language impairment can
  perform a task that utilises one of these
  components as accurately and as fast as a
  non-brain damaged person of the same age,
  education and culture, then it can be assumed
  that that component is not the source of the
  difficulty in word production.

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Print
Heard Speech

Pictures, seen objects
Lexical Semantics
Phonological Output Lexicon
Orthographic Output Lexicon
Phonological Output Buffer
Graphemic Output Buffer
Writing
Speech output
18
Print
Heard Speech
Post-Semantic impairment Speech output

Pictures, seen objects
Lexical Semantics
Phonological Output Lexicon
Orthographic Output Lexicon
Phonological Output Buffer
Graphemic Output Buffer
Writing
Speech output
19
Print
Heard Speech
Post-semantic impairment Speech
output (semantic errors) Written
output Speech comprehension Written
comprehension (assuming no additional
impairments)

?
Pictures, seen objects
?ok
Lexical Semantics
?ok
Phonological Output Lexicon
Orthographic Output Lexicon
Phonological Output Buffer
Graphemic Output Buffer
?ok
Writing
Speech output
20
Print
Heard Speech
Semantic impairment Speech output Written
output Speech comprehension Written
comprehension

Pictures, seen objects
Lexical Semantics
Lexical Semantics
Phonological Output Lexicon
Orthographic Output Lexicon
Phonological Output Buffer
Graphemic Output Buffer
Writing
Speech output
21
Print
Heard Speech
Semantic impairment Speech output (semantic
errors) Written output Speech comprehension
Written comprehension

?
?
Lexical Semantics
Lexical Semantics
Phonological Output Lexicon
Orthographic Output Lexicon
?
Phonological Output Buffer
Graphemic Output Buffer
?
Semantic errors in all modalities
Writing
Speech output
22
Summary
Semantic impairment Post-semantic impairment
Speech output ?semantic errors ?semantic errors
Written output ?semantic errors ?ok
Speech comprehension ?semantic errors ?ok
Written comprehension ?semantic errors ?ok
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Assessment of semantic processing in comprehension
Print
Heard Speech

Pictures, seen objects

• Require an assessment that has semantically
  related distractors
• Perform the assessment in both spoken and written
  forms

Lexical Semantics
Lexical Semantics
Phonological Output Lexicon
Orthographic Output Lexicon
Phonological Output Buffer
Graphemic Output Buffer
Writing
Speech output
24
Word-picture matching with semantically related
distractors
Close semantic distractor
Unrelated distractor
Distant semantic distractor
target
Similar assessment of comprehension found
in PALPA.
25
Word-picture verification (a more sensitive test
of semantic impairments)
Target (response yes) Is this a pair of shoes?

Semantically related distractor (response
no) Is this an aeroplane?
Unrelated distractor (response no ) Is this a
water melon?
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Pyramids Palm trees (Howard Patterson, 1992)
pyramid
pyramid
Arthur 3 picture version 87 1 written
word-2 pictures 87 1 spoken word-2
pictures 85
Semantic impairment
N52 Controls score 94 correct or higher
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Marie(developmental language impairment)

• Squirrel - nut test
• (Pitchford Eames, 1994)
• 95 correct (within normal limits for age matched
  controls)
• British Picture Vocabulary Scale
• Standard Score 99 (average 100)

Post-semantic impairment restricted to spoken
word production
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Different error types in word retrieval

• Arthur Marie make semantic errors
• Arthur spider -gt ant
• Marie Pineapple -gt not apple juice,
• oh the fruit with the funky hairdo
• Chris Becca make phonological errors
• Chris Submarine -gt /sup?b?n?n s?b?bri
• s?b m?rin/
• Becca Hospital -gt / h?st?b?l /

29
Different error types in word retrieval

• Arthur Marie make semantic errors
• Arthur spider -gt ant
• Marie Pineapple -gt not apple juice,
• oh the fruit with the funky hairdo
• Chris Becca make phonological errors
• Chris Submarine -gt /sup?b?n?n s?b?bri
• s?b m?rin/
• Becca Hospital -gt / h?st?b?l /

Semantic impairment
Post-Semantic impairment
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Unimpaired spoken naming
Picture naming
tail
purrs
fur
Lexical semantics
barks
fins
pet
4-legs
Phonological output lexicon
f-i-sh
d-o-g
c-a-t
f
a
a
i
c
sh
c
t
Phonological output buffer
t
cat
31
Unimpaired spoken naming
Picture naming (phonological errors)
tail
purrs
fur
Lexical semantics
barks
fins
pet
4-legs
Phonological output lexicon
f-i-sh
d-o-g
c-a-t
f
a
a
i
c
sh
?
c
t
Phonological output buffer
t
ca_
cag
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Print
Heard Speech


Pictures, seen objects
Repetition of nonwords
Lexical Semantics
Sublexical reading
Phonological Output Lexicon
Orthographic Output Lexicon
Phonological Output Buffer
Graphemic Output Buffer
Writing
Speech output
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Semantic impairment Post-semantic /lexical access Phonological output buffer
Speech output Errors ? Semantic ? Semantic ? Phonological
Written output ?semantic ?ok
Speech comp. ?semantic ?ok
Written comp. ?semantic ?ok
Phonological errors in repetition reading No No
Yes
No
No
Length effect
?ok
?ok
?ok
Yes
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Chris Phonological output buffer
Speech output Errors Length effect ? Phonological Yes
Written output ?ok
Speech comp. ?ok
Written comp. ?ok
Phonological Errors in repetition reading Yes
1 syllable 86 3 syllable 23
Naming Reading Repetition (words nonwords)
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Chris examples of errors across tasks
Submarine Pyramid
Naming sup?b?n?n p?r?m?nt
Reading s?b?r?lin pr?m?d?d
Repetition s?b?m?n pr?m?m?m
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How do we decide which treatment?

• Each different level of breakdown in word
  production will be best remediated by a different
  type of treatment
• (e.g. Hillis Caramazza, 1994 Nettleton
  Lesser, 1991)
• impaired word meaning (semantics)
• ? treatment focusing on meaning
• impaired retrieval of the phonological form from
  semantics
• ? treatment focusing on providing/accessing the
  phonological form
• impaired phoneme level/phonological encoding
• treatment focusing on phonemes

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How do we decide which treatment?

• Each different level of breakdown in word
  production will be best remediated by a different
  type of treatment
• (e.g. Hillis Caramazza, 1994 Nettleton
  Lesser, 1991)
• Do we have evidence that this approach works?
• Yes and No!!

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Do we have evidence that this approach works?

• Developmental Literature
• Several studies have contrasted semantic and
  phonological tasks
• (e.g. Wing 1990, Hyde Wright et al. 1993)
• with conflicting results
• BUT they have not identified the level of
  breakdown in the children treated
• AND examined the children as a group

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What treatment is appropriate?

• Acquired Aphasia literature
• Word retrieval impairments
• Tasks focusing on semantics and phonology
• - improve word retrieval
• e.g. Howard et al 1985
• Nickels Best 1996

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
40
What treatment is appropriate?

• Acquired Aphasia literature
• Word retrieval impairments
• All the tasks involve activation of both
  semantics and phonology
• But may focus more on semantics.

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
41
What treatment is appropriate?

• Acquired Aphasia literature
• Word retrieval impairments
• All the tasks involve activation of both
  semantics and phonology
• But may focus more on semantics
• or phonology

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
Repeat kangaroo
It starts with /k/
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What treatment is appropriate?

• Acquired Aphasia literature
• Word retrieval impairments
• All the tasks involve activation of both
  semantics and phonology
• They produce long lasting, item specific effects
  in the majority of individuals with impaired
  activation of the correct target in the
  phonological lexicon
• Improves likelihood of the target being
  sufficiently activated to be retrieved
  successfully.

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
43
What treatment is appropriate?

• Acquired Aphasia literature
• Semantic impairments
• The most successful therapy seems to involve
  exploring the semantic attributes of a stimulus.
• e.g. Boyle Coelho, 1995.
• Coelho, McHugh Boyle, 2000.
• Hillis, 1991, 1998.
• Nickels Best, 1996.

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
44
What treatment is appropriate?

• Acquired Aphasia literature
• Semantic impairments

e.g. Nickels Best (1996) AER (Arthur)
Relatedness judgements (with feedback)
Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
Improved naming of treated and untreated stimuli
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What treatment is appropriate?

• Acquired Aphasia literature
• Treatment of phonological errors
• Relatively little adequate published work
• Franklin, Buerk, and Howard (2002) MB
• long sequences of phonologically related
  responses in all speech-production tasks
• Good monitoring ability
• therapy included phoneme discrimination tasks
• judgments of accuracy of target attempts

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
46
What treatment is appropriate?

• Acquired Aphasia literature
• Treatment of phonological errors
• Relatively little adequate published work
• Franklin, Buerk, and Howard (2002) MB
• generalised improvement across items and
  modalities
• they propose that treatment improved the phoneme
  selection impairment

Lexical Semantics
Phonological Output Lexicon
Phonological Output Buffer
Speech
47
Summary

• Identified (some of the) the different levels of
  breakdown that can underlie spoken word
  production impairments
• Semantic
• Post semantic
• Phoneme activation
• Demonstrated that there is evidence that
  treatment targeted at these levels of breakdown
  can be successful (at least in the acquired
  aphasia literature)

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Conclusions

• The Cognitive Neuropsychological approach
  requires..
• Systematic assessment of the component processes
  of language processing
• In order to establish which of these processes
  are intact and which impaired
• Therapy will have the best chance of being
  successful only when the cause of the language
  symptom is understood
• These techniques can be applied to both
  developmental and acquired language disorders.

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• Thank you for your attention.
• Any questions or for further details,
• please do not hesitate to contact me
• lnickels_at_maccs.mq.edu.au