Treatment of Word retrieval impairments: Do we know which tasks work for whom and why? Associate...

Treatment of Word retrieval impairments:

Do we know which tasks work

for whom and why?

Associate Professor Lyndsey Nickels

National Health and Medical Research Council

Senior Research Fellow,

Macquarie Centre for Cognitive Science (MACCS),

Macquarie University, Sydney, Australia

Aim & Structure

This presentation will…• address the systematic research on treatment for

word retrieval disorders• Focus on word retrieval disorders in aphasia

Structure• define the problem & how to assess it• discuss the evidence on treatment approaches

Defining the problem

What do we mean by word retrieval?

• successfully accessing the phonological form of a word from semantics

• exclude impairments of phonological processes and articulation

Phonological Output Lexicon

Speech output

Phonological Buffer / Phonemes

Semantics

Writing

Heard SpeechPrint

Idea, picture or

seen object


Speech output


Semantics

Writing

Heard SpeechPrint

Idea, picture or

seen object

Store of word

meanings

Store of phonological word forms

Phonemes

Assemble phonemes into syllables.Retrieve articulatory plans.

visual object representations; nonlinguistic concepts

Semantics

Object, picture or idea

Phonological Lexicon

PhonologicalBuffer/

Phonemes

Semantics


purrs barksfur pet4-legs scales


PhonologicalBuffer/

Phonemes

Semantics


purrs

cat dog rabbit fish

barksfur pet4-legs scales

houserobin


PhonologicalBuffer/

Phonemes

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Phoneme assembly; Articulatory plan

retrieval

How do you know what level the impairment is?

Why does it matter?

Different levels of impairment

require different

treatment

How do you know what level the impairment is?

Observe behaviour & relate to the model of language processing

What errors do they make in

speech production? What factors

affect the accuracy of their speech production?

How do they do on other tasks that share the

same processing

components?

3 people with aphasia and

word retrieval impairments

Picture naming

Playing instrumenttrumpetAER54% correct

A dog’s residenceGSW52%

correct

A clarinet

/efl .. efltn lfnnt lfnnt lftn lfnt elfn eflnt /

CI58%

correct /su:pbnn sbbri: sb mri:n/

Different error types in word retrieval

AER & GSW : semantic errors

e.g. Saxophone -> trumpet

CI : phonological errors

e.g. Submarine -> /su:pbnn/

How do you know what level the impairment is for AER & GSW?



speech production?

Semantic errors

Semantic impairment?

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Sem impairment

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

How can we confirm what level the impairment is for AER & GSW?



speech production?


same processing

components?Semantic errors



Speech output

Phonological Output Buffer

Lexical Semantics

Writing

Heard SpeechPrint

Idea, Picture, or seen object

Semantic impairment

Lexical Semantics


Speech output


Lexical Semantics

Writing

Heard SpeechPrint


Semantic impairment

Lexical Semantics

Semantic impairment

Speech output:(semantic errors)


Speech output


Lexical Semantics

OrthographicOutput Lexicon

Graphemic Output Buffer

Writing

Heard SpeechPrint


Semantic impairment

Lexical Semantics

Semantic impairment



Speech output


Lexical Semantics



Writing

Heard SpeechPrint

Semantic impairment


Written output:

Speech comprehension:

Written comprehension:

Lexical Semantics

Semantic errors in all modalities


How can we confirm what level the impairment is for AER & GSW?



speech production?


same processing



Impaired comprehension & written naming

How do they do when you

test comprehension & written naming?

Assessment of semantic

processing in comprehension

• Require an assessment that has semantically related distractors

• Perform the assessment in both spoken and written forms


Speech output


Lexical Semantics



Writing

Heard SpeechPrint

Pictures, seen objects

Lexical Semantics

Assessing semantics: PALPA Spoken Word-Picture matching

No. correct (n=40)

AER 37

GSW 38

Controls

Mean 39.29 (SD:1.07; Range 35-40)

2 SDs below the mean = 37.15

37 is considered outside normal limits

“carrot”


Speech output


Lexical Semantics

Writing

Heard SpeechPrint


Semantic impairment

Lexical Semantics

Assessing semantics: PALPA Written Word-Picture matching

No. correct (n=40)

AER 38

GSW 39

Controls

Mean 39.29 (SD:1.07; Range 35-40)

2 SDs below the mean = 37.15

37 is considered outside normal limits

carrot


Speech output


Lexical Semantics

Writing

Heard SpeechPrint



Pyramids & Palm trees (Howard & Patterson, 1992)

pyramid “pyramid”

AER:

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

Does AER have a semantic

impairment?


Speech output


Lexical Semantics



Writing

Heard SpeechPrint


Written output:



Lexical Semantics

?

Does AER have a semantic

impairment?

YES!

Maybe… but it’s a very easy

task

What about GSW?

He can do word-picture matching….

does that mean he has

intact semantics?

Assessing semantics

PALPA wd-pic match

(n=40)

High Image.

Synonym Judgements

“Marriage – lamp”

“Marriage – wedding”

AER 37/38

GSW 38/39

Low Image.

“reality - truth”

“reality-notion”

Assessing semantics

PALPA wd-pic match

(n=40)

High Image.

Synonym Judgements

AER 37

GSW 38

Low Image.

87%^

100%*

63%

90%

Lower limit 38 .98 (37/38)^ .88 (34/38)

of ‘normal’ .93 (28/30)* .83 (25/30)

Maybe… but it’s a very easy

task

What about GSW?

He can do word-picture matching….

does that mean he has

intact semantics?

But he can do synonym

judgements too – so maybe his semantics is

intact

But didn’t we say

semantic errors

were a result of

semantic impairments !

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

How can we confirm what level the impairment is?



speech production?


same processing


Post-Semantic impairment?


Speech output


Lexical Semantics



Writing

Heard SpeechPrint


Post-Semantic impairment

Speech output:


Speech output


Lexical Semantics



Writing

Heard SpeechPrint


Post-semantic impairment


Written output:



(assuming no additional impairments)

ok

ok

ok

What is GSW’s impairment?



speech production?


same processing


Post-Semantic

impairment

Intact comprehension

Summary

Semantic impairment (AER)

Post-semantic impairment

(GSW)

Speech output semantic errors semantic errors

Written output semantic errors ok

Speech comprehension semantic errors ok

Written comprehension semantic errors ok

Heard SpeechPrint

Semantics


Speech output


Writing

Idea, picture or

seen object

Impairments of word retrieval

Semantic impairment

Post-semantic lexical retrieval

impairment

What about CI?

What errors does she make

in speech production?

/efl .. efltn lfnnt lfnnt lftn lfnt elfn eflnt /

/su:pbnn sbbri: sb mri:n/

Phonological errors

Observe behaviour & relate to the model of language processingWhat errors

does she make in speech

production?

What about CI?

Phonological errors

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Impaired phoneme activation

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Impaired phoneme activation

Rapid decay of phoneme activation

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Rapid decay of phoneme activation

Phoneme activation noise

Semantics


purrs

cat dog rabbit fish


houserobin


PhonologicalBuffer/

Phonemesæ td o gk

Phoneme activation noise


Speech output


Lexical Semantics



Writing

Heard SpeechPrint


Phoneme level impairment

Speech output:(Phonological errors)

Written output:



(assuming no additional impairments)

ok

ok

ok

Phoneme level impairment


Speech output


Lexical Semantics



Writing

Heard SpeechPrint


Repetition of nonwords

Sublexical reading

CI – examples of errors across tasks

Submarine Pyramid

Naming su:pbnn prmnt

Reading sbrli:n prmdd

Repetition sbmn prmmm

Semantic impairment

Post-semantic /lexical access

Phoneme level

Speech outputErrors

Semantic

Semantic

Phonological

Written output semantic ok

Speech comp. semantic ok

Written comp. semantic ok

Errors in repetition & reading

No No

ok

ok

ok

Yes


What errors does she make

in speech production?

What about CI?

Phonological errors

Phoneme level

impairment


same processing

components?

Intact comprehension

& written naming but

impaired repetition and

reading of words and nonwords

What factors affect the

accuracy of their speech production?

Semantic impairment

Post-semantic /lexical access

Phoneme level

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

FrequencyImageabilitySemantic category

Effects of.. Frequency Number of phonemes

CI 1 syllable: 86%3 syllable: 23%

Aim & Structure

This presentation will…• address the systematic research on treatment for

word retrieval disorders• Focus on word retrieval disorders in aphasia

Structure

• define the problem & how to assess it

• discuss the evidence on treatment approaches

Done!

Defining the problem

What do we mean by word retrieval?

• successfully accessing the phonological form of a word from semantics

• exclude impairments of phonological processes and articulation

i.e. Semantic impairments & post-semantic impairmentsDifferent levels of impairment

require different

treatment

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

We’ll discuss the evidence for which kinds

of treatment are most effective for each level of

impairment.

In other words … what works!

But how can we tell if it works?

Use some straightforwar

d methodological

controls

Eh????

What do we need to know?

Is there any change in performance?


Test naming before (preferably more than once)

and after treatment ….

has it improved?

Is there any change in performance?

Is the change due to your therapy?

And then swap and treat the other half …

do they improve now?




has it improved?

Treat half the items and not

another half … do the ones you treat improve and not the others (or not

as much)?

And then swap and treat the other half …

do they improve now?




has it improved?

Treat half the items and not

another half … do the ones you treat improve and not the others (or not

as much)?

Test other tasks that you would predict would

improve (generalisation) …. have they?

Test other tasks that you would predict would NOT improve

(control task) ….have they?

How do we know if it works?

• We can only tell if our therapy works if we use good methodological controls

• these are not just for researchers – they are for everybody

• Use enough items that you can tell if the change is real (8 items is not enough!)

• To examine effects at other levels (e.g. connected speech, conversation, quality of life) use measures that will be sensitive to your intervention.

Time for a break!

Treatment of Word retrieval impairments: Do we know which tasks work for whom and why? Associate...

Documents

Transcript of Treatment of Word retrieval impairments: Do we know which tasks work for whom and why? Associate...