Levels of breakdown in impaired word retrieval Associate Professor Lyndsey Nickels Macquarie Centre...
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Transcript of Levels of breakdown in impaired word retrieval Associate Professor Lyndsey Nickels Macquarie Centre...
Levels of breakdown in impaired word retrieval
Associate Professor Lyndsey Nickels
Macquarie Centre for Cognitive Science (MACCS)
Macquarie University, Sydney.
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%
Cognitive Neuropsychology: An Assumption
• Treatment will be maximally effective only when the direction of treatment is determined by precise knowledge of the individual’s 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.
Arthur(acquired aphasia)
Spider -> “ant”
Pocket -> “sleeve”
Arthur (acquired aphasia)
Marie(developmental language impairment)
Pineapple -> “not apple juice,
oh the fruit with
the funky hairdo”
From Best, 2005
Submarine -> /su:pbnn sbbri: sb mri:n/
Chris (acquired aphasia)
Chris (acquired aphasia)
Elephant -> /efl .. efltn lfnnt lfnnt lftn lfnt
elfn eflnt /
Becca(Developmental language impairment)
Hospital -> /əə/From Best 2005
Different error types in word retrieval
Arthur & Marie make semantic errors
Arthur spider -> “ant”
Marie Pineapple -> “not apple juice,
oh the fruit with the funky hairdo”
Chris & Becca make phonological errors
Chris Submarine -> /su:pbnn sbbri:
sb mri:n/
Becca Hospital -> / əə /
WHY do these different error types occur?
f-i-sh
d og
purrs
barksfur
pet 4-legs
tail
fins
d-o-g c-a-t
cat
Phonological output lexicon
Phonological output buffer
Lexical semantics
Picture naming
ca
tf i s
hca
t
c-a-td-o-g f-i-sh
How do semantic errors occur?
Semantic errors are most commonly attributed to semantic impairments …….
i.e. Impaired representation of word meanings
ArthurSpider -> “ant”
Marie Pineapple -> “the fruit with the funky hairdo”
f-i-sh
d og
purrs
barksfur
pet 4-legs
tail
fins
d-o-g c-a-t
dog
Phonological output lexicon
Phonological output buffer
Lexical semantics
Picture naming
(with semantic impairment)
ca
tf i s
hd o
g
f-i-shc-a-td-o-gd-o-g
f-i-sh
d og
barksfur
pet 4-legs
tail
fins
d-o-g c-a-t
dog
Phonological output lexicon
Phonological output buffer
Lexical semantics
Semantic errors
(without semantic impairment)
ca
tf i s
hd o
g
f-i-shc-a-td-o-gd-o-g
purrs
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?
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.
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Pictures, seen objects
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Pictures, seen objects
Post-Semantic impairment
Speech output:
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Pictures, seen objects
Post-semantic impairment
Speech output:(semantic errors)
Written output:
Speech comprehension:
Written comprehension:
(assuming no additional impairments)
ok
ok
ok
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Pictures, seen objects
Semantic impairment
Speech output:
Written output:
Speech comprehension:
Written comprehension:
Lexical Semantics
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Semantic impairment
Speech output:(semantic errors)
Written output:
Speech comprehension:
Written comprehension:
Lexical Semantics
Semantic errors in all modalities
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
Assessment of semantic
processing in comprehension
• Require an assessment that has semantically related distractors
• Perform the assessment in both spoken and written forms
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Pictures, seen objects
Lexical Semantics
Word-picture matching with semantically related distractors
Distant semantic distractor
target
Close semantic distractor
Unrelated distractor
Similar assessment of comprehension found inPALPA.
Word-picture verification (a more sensitive test of semantic impairments)
Semantically related distractor (response: ‘no’)Is this an aeroplane?
Unrelated distractor (response: ‘no’ )Is this a water melon?
Target (response: ‘yes’)Is this a pair of shoes?
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%
N=52Controls score 94% correct or higher Sem
antic
impa
irmen
t
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
Different error types in word retrieval
Arthur & Marie make semantic errors
Arthur spider -> “ant”
Marie Pineapple -> “not apple juice,
oh the fruit with the funky hairdo”
Chris & Becca make phonological errors
Chris Submarine -> /su:pbnn sbbri:
sb mri:n/
Becca Hospital -> / əə /
Different error types in word retrieval
Arthur & Marie make semantic errors
Arthur spider -> “ant”
Marie Pineapple -> “not apple juice,
oh the fruit with the funky hairdo”
Chris & Becca make phonological errors
Chris Submarine -> /su:pbnn sbbri:
sb mri:n/
Becca Hospital -> / əə /
Semantic impairment
Post-Semantic impairment
f-i-sh
d og
purrs
barksfur
pet 4-legs
tail
fins
d-o-g c-a-t
cat
Phonological output lexicon
Phonological output buffer
Lexical semantics
Picture naming
ca
tf i s
hca
t
c-a-td-o-g f-i-sh
f-i-sh
d og
purrs
barksfur
pet 4-legs
tail
fins
d-o-g c-a-t
ca_
Phonological output lexicon
Phonological output buffer
Lexical semantics
Picture naming (phonological errors)
ca
tf i s
hca
t
c-a-td-o-g f-i-sh
cag
Phonological Output Lexicon
Speech output
Phonological Output Buffer
Lexical Semantics
OrthographicOutput Lexicon
Graphemic Output Buffer
Writing
Heard SpeechPrint
Pictures, seen objects
Repetition of nonwords
Sublexical reading
Semantic impairment
Post-semantic /lexical access
Phonological output buffer
Speech outputErrors
Semantic
Semantic
Phonological
Written output semantic ok
Speech comp. semantic ok
Written comp. semantic ok
Phonologicalerrors in repetition & reading
No No
ok
ok
ok
Yes
YesNoNoLength effect
Chris Phonological output buffer
Speech outputErrors
Length effect
Phonological
YesWritten output ok
Speech comp. ok
Written comp. ok
PhonologicalErrors in repetition & reading
Yes
1 syllable: 86%3 syllable: 23%
NamingReading Repetition(words & nonwords)
Chris – examples of errors across tasks
Submarine Pyramid
Naming su:pbnn prmnt
Reading sbrli:n prmdd
Repetition sbmn prmmm
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
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!!
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
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 Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
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….
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
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
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
Repeat “kangaroo”
It starts with /k/
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.
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
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.
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
What treatment is appropriate?Acquired Aphasia literature:
Semantic impairments
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
e.g. Nickels & Best (1996) AER (Arthur)
“Relatedness judgements” (with feedback)
Improved naming of treated and untreated stimuli
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
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
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
Phonological Output Buffer
Speech
Phonological Output Lexicon
Lexical Semantics
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)
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.
Thank you for your attention.
Any questions or for further details,
please do not hesitate to contact me: