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

Heard Speech Print Idea, picture or seen object Semantics Phonological Output Lexicon Phonological Buffer / Phonemes Speech output Writing

Store of phonological word forms Print Heard Speech visual object representations; nonlinguistic concepts Idea, picture or seen object Store of word meanings Store of phonological word forms Semantics Phonological Output Lexicon Phonological Buffer / Phonemes Assemble phonemes into syllables. Retrieve articulatory plans. Phonemes Speech output Writing

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics Phonological Lexicon PhonologicalBuffer/ Phonemes

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs 4-legs fur barks pet scales Phonological Lexicon PhonologicalBuffer/ Phonemes

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs fur barks 4-legs pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house So that’s the processes you or I go through when saying a word. Now we will turn to aphasia… In aphasia there can be different levels of impairment that will each affect word production PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house So that’s the processes you or I go through when saying a word. Now we will turn to aphasia… PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t 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 How do they do on other tasks that share the same processing components? What errors do they make in speech production? What factors affect the accuracy of their speech production? 3 people with aphasia and word retrieval impairments

/su:pbnn sbbri: sb mri:n/ Picture naming AER 54% correct trumpet Playing instrument GSW 52% correct A dog’s residence A clarinet CI 58% correct /efl .. efltn lfnnt lfnnt lftn lfnt elfn eflnt / /su:pbnn sbbri: sb mri:n/

Different error types in word retrieval AER & GSW : semantic errors e.g. Saxophone -> trumpet CI : phonological errors e.g. Submarine -> /su:pbnn/

How do you know what level the impairment is for AER & GSW? Observe behaviour & relate to the model of language processing Semantic impairment? What errors do they make in speech production? Semantic errors

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Sem impairment Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

How can we confirm what level the impairment is for AER & GSW? Observe behaviour & relate to the model of language processing Semantic impairment? How do they do on other tasks that share the same processing components? What errors do they make in speech production? Semantic errors

Semantic impairment Heard Speech Print Idea, Picture, or seen object Lexical Semantics Lexical Semantics Phonological Output Lexicon Phonological Output Buffer Speech output Writing

Semantic impairment Heard Speech Print Idea, Picture, or seen object Lexical Semantics Lexical Semantics Phonological Output Lexicon Phonological Output Buffer Speech output Writing

 Semantic impairment Speech output: (semantic errors) Print Heard Speech Semantic impairment Speech output: (semantic errors) Semantic impairment Idea, Picture, or seen object  Lexical Semantics Lexical Semantics Phonological Output Lexicon Phonological Output Buffer Speech output Writing

 Semantic impairment Semantic impairment Speech output: Print Heard Speech Semantic impairment Semantic impairment Speech output: (semantic errors) Idea, Picture, or seen object  Lexical Semantics Lexical Semantics Phonological Output Lexicon Orthographic Output Lexicon Phonological Output Buffer Graphemic Output Buffer Speech output Writing

    Semantic errors in all modalities Semantic impairment Print Heard Speech Semantic impairment Speech output: (semantic errors) Written output: Speech comprehension: Written comprehension: Idea, Picture, or seen object   Lexical Semantics Lexical Semantics  Phonological Output Lexicon Orthographic Output Lexicon Phonological Output Buffer Graphemic Output Buffer  Semantic errors in all modalities Speech output Writing

How can we confirm what level the impairment is for AER & GSW? Observe behaviour & relate to the model of language processing Semantic impairment? How do they do on other tasks that share the same processing components? What errors do they make in speech production? Impaired comprehension & written naming Semantic errors How do they do when you test comprehension & written naming?

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 Speech output Writing

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”

Semantic impairment Heard Speech Print Idea, Picture, or seen object Lexical Semantics Lexical Semantics Phonological Output Lexicon Phonological Output Buffer Speech output Writing

Assessing semantics: PALPA Written Word-Picture matching No. correct (n=40) AER 38 GSW 39   carrot Controls Mean 39.29 (SD:1.07; Range 35-40) 2 SDs below the mean = 37.15 37 is considered outside normal limits

Semantic impairment? Heard Speech Print Idea, Picture, or seen object Lexical Semantics Phonological Output Lexicon Phonological Output Buffer Speech output Writing

Pyramids & Palm trees (Howard & Patterson, 1992) AER: 3 picture version: 87% 1 written word-2 pictures: 87% 1 spoken word-2 pictures: 85% Semantic impairment N=52 Controls score 94% correct or higher

Does AER have a semantic impairment?

Does AER have a semantic impairment? Print Heard Speech Speech output: (semantic errors) Written output: Speech comprehension: Written comprehension: Does AER have a semantic impairment?  ? Lexical Semantics Lexical Semantics  Phonological Output Lexicon Orthographic Output Lexicon Phonological Output Buffer Graphemic Output Buffer YES!  Speech output Writing

Maybe… but it’s a very easy task What about GSW? Maybe… but it’s a very easy task He can do word-picture matching…. does that mean he has intact semantics?

Assessing semantics PALPA wd-pic match AER 37/38 GSW 38/39 (n=40) Synonym Judgements High Image. Low Image. AER 37/38 GSW 38/39 “Marriage – lamp” “Marriage – wedding” “reality - truth” “reality-notion”

Assessing semantics PALPA wd-pic match AER 37 GSW 38 87%^ 100%* 63% Synonym Judgements High Image. Low Image. AER 37 GSW 38 87%^ 100%* 63% 90% It becomes clear that despite his relatively good performance on word-picture matching CTJ does have a semantic impairment when tested on alternative stimuli - 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? But didn’t we say semantic errors were a result of semantic impairments ! Maybe… but it’s a very easy task 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

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics purrs barks 4-legs fur pet scales Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

How can we confirm what level the impairment is? Observe behaviour & relate to the model of language processing Post-Semantic impairment? How do they do on other tasks that share the same processing components? What errors do they make in speech production? Semantic errors

Post-Semantic impairment 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 Speech output Writing

 ok ok ok Post-semantic impairment Speech output: 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 Speech output Writing

What is GSW’s impairment? Observe behaviour & relate to the model of language processing Post-Semantic impairment How do they do on other tasks that share the same processing components? What errors do they make in speech production? Intact comprehension Semantic errors

semantic errors ok Summary Semantic impairment (AER) Post-semantic impairment (GSW) Speech output semantic errors Written output ok Speech comprehension Written comprehension

Post-semantic lexical retrieval impairment Impairments of word retrieval Heard Speech Print Semantics Phonological Output Lexicon Speech output Phonological Buffer / Phonemes Writing Idea, picture or seen object Semantic impairment Post-semantic lexical retrieval impairment What’s the problem? Figure 1 shows a simple model of the steps involved in producing a word from a concept. Figure 2 spells these steps out in greater detail, using the example of producing the word corresponding to the concept ‘dog’.

What about CI? What errors does she make in speech production? /su:pbnn sbbri: sb mri:n/ Phonological errors /efl .. efltn lfnnt lfnnt lftn lfnt elfn eflnt /

Observe behaviour & relate to the model of language processing What about CI? Observe behaviour & relate to the model of language processing What errors does she make in speech production? Phonological errors

PhonologicalBuffer/ Phonemes Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house So that’s the processes you or I go through when saying a word. Now we will turn to aphasia… PhonologicalBuffer/ Phonemes k d æ o g t

Impaired phoneme activation

PhonologicalBuffer/ Phonemes Impaired phoneme activation Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house So that’s the processes you or I go through when saying a word. Now we will turn to aphasia… PhonologicalBuffer/ Phonemes k d æ o g t

PhonologicalBuffer/ Phonemes Impaired phoneme activation Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house So that’s the processes you or I go through when saying a word. Now we will turn to aphasia… PhonologicalBuffer/ Phonemes k d æ o g t

Rapid decay of phoneme activation

PhonologicalBuffer/ Phonemes Rapid decay of phoneme activation Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house So that’s the processes you or I go through when saying a word. Now we will turn to aphasia… PhonologicalBuffer/ Phonemes k d æ o g t

Phoneme activation noise

PhonologicalBuffer/ Phonemes Phoneme activation noise Object, picture or idea Semantics barks fur pet 4-legs scales purrs Phonological Lexicon robin cat dog rabbit fish house PhonologicalBuffer/ Phonemes k d æ o g t

 ok ok ok Phoneme level impairment Speech output: Print Phoneme level impairment Speech output: (Phonological errors) Written output: Speech comprehension: Written comprehension: (assuming no additional impairments) Heard Speech  Pictures, seen objects ok Lexical Semantics ok Phonological Output Lexicon Orthographic Output Lexicon ok Phonological Output Buffer Graphemic Output Buffer Speech output Writing

Phoneme level impairment Print Phoneme level impairment Heard Speech Pictures, seen objects Repetition of nonwords Lexical Semantics Sublexical reading Phonological Output Lexicon Orthographic Output Lexicon Phonological Output Buffer Graphemic Output Buffer Speech output Writing

CI – examples of errors across tasks Submarine Pyramid Naming su:pbnn prmnt Reading sbrli:n prmdd Repetition sbmn prmmm

  Phonological semantic ok ok ok ok Yes No Semantic impairment Post-semantic /lexical access Phoneme level Speech output Errors  Semantic  Phonological Written output semantic ok Speech comp. Written comp. Errors in repetition & reading No ok ok ok Yes

Phoneme level impairment What about CI? Observe behaviour & relate to the model of language processing Phoneme level impairment What errors does she make in speech production? How do they do on other tasks that share the same processing components? What factors affect the accuracy of their speech production? Intact comprehension & written naming but impaired repetition and reading of words and nonwords Phonological errors

  Phonological semantic ok ok ok ok Yes No Semantic impairment Post-semantic /lexical access Phoneme level Speech output Errors  Semantic  Phonological Written output semantic ok Speech comp. Written comp. Phonological errors in repetition & reading No Frequency Imageability Semantic category Number of phonemes Effects of.. Frequency ok CI 1 syllable: 86% 3 syllable: 23% ok ok Yes

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! In this presentation I will address the systematic research on treatment for word retrieval disorders. While the focus will be on word retrieval impairments in aphasia, the same principles should be generally applicable to the treatment of word retrieval disorders in other populations. There is clear evidence that word retrieval in progressive disorders (e.g. Primary progressive aphasia, Dementia) can be improved with ‘loss’ being slowed for treated items. Similarly, techniques that have been successfully used with people with aphasia have also been applied to children with word retrieval disorders as part of their impaired language development. So what works? One of the problems with evidence-based practice in general, and this question in particular, is that unless you define the problem in enough detail you can never give a sensible answer. Hence, first we will need to define what we mean by word retrieval. I will use ‘word retrieval’ to refer to successfully accessing the phonological form of a word from semantics, and we will exclude impairments of phonological processes and articulation. I will use a simple model of the steps involved in producing a word from a concept, and discuss the consequences of word retrieval failing at each of these steps. What errors might be expected to occur and how can we determine the level of breakdown? Having defined the problem, and described what underlying impairments could cause it, we will return to the original question – what will improve impaired word retrieval? We will discuss the evidence from current research and draw conclusions regarding the most profitable treatment approaches. In addition, we will discuss the limitations of our knowledge, in particular the fact that we still cannot guarantee the effectiveness of a particular task for a particular person with a particular level of breakdown. Finally, we will discuss the implications of these limitations for the clinician implementing treatment in their clinical practice.

Different levels of impairment require different treatment 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 impairments Different levels of impairment require different treatment What’s the problem? Figure 1 shows a simple model of the steps involved in producing a word from a concept. Figure 2 spells these steps out in greater detail, using the example of producing the word corresponding to the concept ‘dog’. First, you see a dog or have the idea that you want to talk about a dog. This object, picture or idea will activate the stored concept or meaning associated with dog in the semantic system. In figure 2 this is represented as a set of semantic features which include [has fur] [barks] [has four legs] [is a pet]. These semantic features in turn activate stored lexical knowledge. Hence [has fur] is true of cat, dog and rabbit, so all of these words will be activated. However, ‘dog’ will be the most activated item in the phonological output lexicon, as only dog will be activated by all four features, while cat and rabbit will be activated by three and fish by one. Therefore, as the most active item in the lexicon, dog will be selected and will activate its phonemes. These phonemes will then be assembled into a syllable, the articulatory plans for that syllable retrieved and the word produced by the oral musculature. Here we define word retrieval as selection of the word form. In other words, the point at which ‘dog’ is the most active in the lexicon and is selected is the point at which we will say ‘dog’ has been retrieved.

How do we decide which treatment? In other words … what works! We’ll discuss the evidence for which kinds of treatment are most effective for each level of impairment. 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 Eh???? But how can we tell if it works? Use some straightforward methodological controls

Is there any change in performance? What do we need to know? Is there any change in performance?

Test naming before (preferably more than once) and after treatment …. 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? ?

? What do we need to know? Is the change due to your therapy? And then swap and treat the other half … do they improve now? Treat half the items and not another half … do the ones you treat improve and not the others (or not as much)? Is the change due to your therapy? Test naming before (preferably more than once) and after treatment …. has it improved? ?

What do we need to know? And then swap and treat the other half … do they improve now? 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 naming before (preferably more than once) and after treatment …. has it improved? 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!