Language and Cognition Colombo, June 2011

1. Language and CognitionColombo, June 2011 Day 9 Aphasia: disorders of syntax

2. Agrammatism • Deficits in syntactic aspects of production and comprehension of sentences • Word level is often (comparatively) spared • Agrammatism has been identified in other clinical populations, but has been studied most extensively in Broca’s aphasics

3. Characteristics of Broca’s aphasia • Spoken language: • Short phrase length, limited range of syntactic structures • Telegraphic speech – primarily content words (function word omission) • Speech may be very effortful – prosody is often abnormal • Articulatory difficulties are common (apraxia / dysarthria) • Poor repetition • Disrupted naming ability • A range of impairments in reading and writing • Receptive language: • Relatively good for single words and short sentences • Impairments in comprehension of grammatically complex sentences • Often very good insight into deficits

4. Syntax • Structure in language – just like structure in (the rest of) nature

5. The sailor is kissing the girl

6. Syntactic movement • The sailor is kissing the girl • Who is the sailor kissing? • The sailor is kissing who • Who is the sailor tis kissing tthe girl/who? • Movement leaves “traces” behind

7. Mapping • It’s not enough to “know” (implicitly) what the structure of a sentence is • We also have to know how to interpret the structure • Thematic roles (also called theta theory, argument structure etc): • subject of a sentence is usually the AGENT of the verb • Object of a sentence is usually the PATIENT or THEME of the verb

8. Mapping • Theta-roles: assignment of interpretive roles to syntactic objects subject verb object Grammatical roles John kissed Mary Theta roles • Non-canonical word order  reliance on grammatical structure object verb subject John was kissed by Mary Agent Patient Agent?? Patient??

9. In English…. • Mapping between theta roles and grammatical roles is achieved by using word order • Subject first = Agent • Object first is non-canonical, and indicates a passive

10. In Sinhala…. • Literary and colloquial language varieties • There is a passive construction in the literary variety of Sinhala • Mapping between theta roles and syntactic roles is achieved using grammatical morphemes – NOT by changing word order

11. In Sinhala…. • The colloquial variety only has the active construction • BUT there are volitive and involitive ways to express the same sentence

12. In Sinhala…. • Sinhala passive requires the Agent to be in a position at the front of the sentence • Other constructions seem to show free word order All Sinhala examples are from Gunasinghe & Kess, 1985 http://sealang.net/sala/archives/pdf8/kess1985preliminaries.pdf

13. Agrammatism in English and Sinhala • English: omitted morphemes • Sinhala: substituted morphemes • English: passive is interpreted like active • Sinhala: nonvolitional may be interpreted like volitional

14. Agrammatic comprehension • Sentence-picture matching tasks • Non-reversible sentences are easier to interpret than reversible ones • Canonical sentences – subject-verb-object – are easier to interpret than non-canonical ones • Passive vs active • Object relative vs subject relative • Less complex phrase structure makes a sentence easier to understand

15. The mother is calling her child who has light hair

16. The woman who is fat is kissing her husband

17. Syntactic trees

18. Questions (in English)

19. In Sinhala… • Sinhala is considered a “wh in situ” language • That means it does not move wh elements from one position in the sentence to another • BUT whether we are speakers of English or Sinhala (or whatever) there is evidence to show that we all apply the SAME processes of linguistic analysis to understanding sentences • Underneath it all, it seems that every language DOES move WH items • In some languages, the WH item is pronounced in its moved position (this is called OVERT movement) • In some languages, the WH item is pronounced at the trace position (this is called COVERT movement)

20. Maybe agrammatism = central syntactic deficit • Caramazza and Zurif, 1976 • Agrammatic aphasics DO have comprehension problems • They have difficulties understanding sentences when they must rely on syntactic knowledge to do so • This parallels their production deficits • They have lost knowledge of syntactic structure (affects all modalities in similar ways)

21. Another view: is agrammatism a problem with mapping? • Problems with the central syntactic deficit account: • agrammatics do have some ability to interpret complex utterances - in particular, they are quite good at grammaticality judgement • Some agrammatics are modality-specifically impaired – note assumptions of central deficit hypothesis • Some fluent aphasics show comprehension deficits similar to those found in Broca’s aphasics • Perhaps the deficit is not central to syntax, but involves only the mapping between syntax and interpretation of sentences (Saffran et al 1980)

22. Is agrammatism a problem with syntactic representations? The trace deletion hypothesis • We have seen that things move around in sentences • And we have seen that interpreting sentences does not just mean knowing where the subject and the object are – it means knowing what theta roles to assign, too • In the normal language system, movement leaves traces behind • Theta roles can be assigned to traces, and then transmitted to the moved item • Grodzinsky (1990) asked: what if traces get deleted from the syntactic representation? • Maybe this is what happens in agrammatism • The trace deletion hypothesis

23. If traces are deleted… • No problem understanding a sentence where nothing has moved (i.e., canonical word order) • Problems come when trying to understand sentences where movement has occurred (i.e., non-canonical word order) • Without traces to help them understand where the moved elements have come from, agrammatic aphasics cannot figure out the roles of the subject and the object in a sentence • So they guess  chance performance

24. In Sinhala… • If traces are deleted, word order will be free • This might change things for production: • WH items might be produced in moved positions? – may not matter given free word order • But it is predicted to cause problems for comprehension, because the reconstruction of underlying structure is important for sentence interpretation in every language

25. Trace Deletion Hypothesis • Assigning a theta role to ‘the girl’ should be no problem – no trace involved in that • P ‘by’ assigns a theta role of Agent – so ‘the girl = Agent • But, if traces are deleted, then ‘the boy’ has no theta role • So follow your instincts – USUALLY, the first noun in a sentence is the Agent • So ‘the boy’ is probably an Agent • Now, the agrammatic thinks: ‘the boy’ = Agent AND ‘the girl’ = Agent • What to do? GUESS at the right interpretation of this sentence

26. A simpler view… • Ouhalla (1993) and others • The syntactic tree of a typical sentence is large and complex • People who have an agrammatic deficit may be unable to access higher parts of the tree

27. Recommendations: • So, we should not be using the higher parts of the tree, so far as possible, when working with agrammatic patients • Can educate communicative partners this way too – show how a wh question involves a great deal of syntactic complexity; a yes-no question is relatively simpler; passives, relative clauses and locatives may overload the system very easily • simplest of all is an active, nonreversible statement

28. Planning intervention What person can do cannot do does do What person needs to do wants to do closing the gap

29. Planning intervention What person cannot do can do does do What person needs to do wants to do closing the gap Desired ability Person needs/wants to make statements & requests needs/wants to ask questions and socially converse Cannot produce a variety of syntactic constructions Communicates through use of substantive words and occasional, simple syntactic constructions Has relatively spared auditory comprehension

30. Treating sentence level deficits: a mapping approach Recall: the Mapping Hypothesis There is not a problem in syntax per se; the problem is in assigning thematic roles to grammatical objects MAPPING THERAPY Present a typed sentence Make the thematic roles explicit Where are thematic roles assigned from? What’s the main word in this sentence? What is this sentence about? What action is happening here? What’s the Agent? Which one is doing the V-ing? What’s the Patient? Which one is getting V-ed? What is s/he V-ing? Pre and post testing Generalization issues Schwartz, MF, Saffran, EM, Fink, RB, Myers, JL, Martin, N. (1994) Mapping therapy: A treatment program for agrammatism. Aphasiology, 8: 19-54.

31. Treating sentence level deficits: TDH Linguistic specific treatment (LST) Thompson et al, 1993 onwards Train subjects to recognize parts of the sentence, and then show them how to move things to form questions Generalized to new sentences, and also from ‘who’ questions to ‘what’ questions Also helpful for training on cleft sentences; may extend to passives Thompson, C. K., Shapiro, L. P., Ballard, K. J., Jacobs, B. J., Schneider, S. L., & Tait, M. E. (1997). Training and generalized production of wh- and NP-movement structures in agrammatic aphasia. Journal of Speech, Language, and Hearing Research, 40, 228–244.

32. The man is sending flowers what Agent Aux verb

33. is The man sending what Agent verb 1. Move Aux to front (= I to C movement)

34. what is The man sending Agent verb 2. Move wh word to front (= wh movement to spec, CP)

35. Production of grammatical morphemes Production deficit in nonfluent aphasics Cannito & Vogel, 1980: Training regular plurals on nouns – no carryover to irregular plurals Thompson et al 1982: Matrix training of prepositional forms, allows for testing of generalization Kearns & Salmon 1984: Training on copula is found to generalize to auxiliary is (but not to is+locative)

37. Training sentence production Syntax Production Program for Aphasia (Helm-Estabrooks 1981) / Direct Production Training (Wambaugh & Thompson 1989) Story completion format Again, limited generalization to untrained sentence types Little effect on spontaneous language production

38. Functional communication E.g. Promoting Aphasics Communicative Effectiveness (PACE) Clinician and client participate equally There is an exchange of new information Speaker can choose modality Feedback focuses on adequacy of message Training conversational partners Spouses, volunteers Get the message in Provide a means for getting messages out Maintain the flow of conversation You have to want to communicate

39. The importance of assessment • Assessment can be hypothesis driven • We need to compare the observed deficits with a model of normal processing • Then we can formulate a hypothesis about what has gone wrong for some individual – and what they can still do • Example: if someone has a problem with wh question production • Could be an issue with syntactic movement • So test other constructions involving movement – such as passives, object relatives • If they are bad at these also, then movement may indeed be the problem • If they are good at these, in contrast with questions, then maybe their problem is one with representing higher levels in the syntactic tree • Then you test other constructions involving higher levels in the tree – such as embedded clauses

40. The importance of assessment • If we have a model, we can test / assess at each level of the model and form more precise hypotheses about the nature of the Pt’s impairment  more focused intervention • Relating aphasic language impairments to models of normal language function at least “forces one to think hard and with precision about the patient” (Byng et al 1990)