Disorders of Syntax and Morphology

1. Ling 411 – 08 Disorders of Syntax and Morphology Goodglass 1993: Chapter 6

2. REVIEW Extra-Sylvian Aphasic Syndromesand repetition • In all perisylvian syndromes, repetition is faulty • In all extra-sylvian aphasic syndromes, repetition is intact (why?) • “Aphasia without repetition disturbance almost invariably indicates pathology outside the perisylvian region” (B&A 1996:146)

3. REVIEW Major Language Areas Supramarginal gyrus (Goldstein’s area) Angular gyrus (Geschwind’s area) Wernicke’s area Exner’s area Broca’s area Superior parietal lobule

4. Agrammatism • Generally present in Broca’s aphasia • Usually associated with Broca’s aphasia • But other aphasics also have grammatical dysfunctions • Paragrammatism – common in Wernicke aphasia • A lot of variation among different patients

5. Agrammatism: an early observation (1819) • Deleuze (1819), referring to a French-speaking patient: The patient “used exclusively the infinitive of verbs and used no pronouns. … She produced absolutely no conjugated verb.” Goodglass 1993: 104

6. Agrammatism vs. Paragrammatism • Paragrammatism – too much speech • Normal or excessive fluency • Use of inappropriate words • Neologisms • No lack of function words and inflections • But not always used appropriately • Common in Wernicke’s aphasia • Agrammatism – not enough speech • Lack of fluency • Omission (NOT deletion!*) of function words and inflections • Common in Broca’s aphasia *Next slide

7. Omission vs. Deletion • Goodglass (106): • Sentences with a deleted main verb (“Joan and I . . . Coffee”) may continue to appear. • . . . misuse or deletions of morphology . . . • Is he talking about deletion or omission? • Deletion implies that it was first there, and then removed • Omission – it wasn’t put in at all • Goodglass is following a practice that was common among linguists at the time he wrote the book

8. Broca’s Aphasia • Damage to frontal lobe • Mainly, inferior frontal gyrus • Largely intact comprehension • Nonfluent, agrammatic speech • “Telegraphic speech” – • Abundance of content words (e.g., nouns) • Lack of function words (e.g. prepositions) • Impaired verb processing • Bates, Chen, Tzeng, Li & Opie, 1991; Damasio & Tranel, 1993; Daniele, Giustolisi, Silveri, Colosimo & Gainotti, 1994; Lamb & Zhang, 2010; Shapiro & Caramazza, 2003

9. REVIEW Subtypes of Broca aphasia(acc. to Benson & Ardila) • Type I • A.k.a. little Broca aphasia • Milder defects • Less extensive damage • Better prognosis • Type II • Symptoms worse • More extensive damage • These are not distinct, but variations • Two spans along a scale

10. Example of agrammatic speech Examiner:Can you tell me about why you came back to the hospital? Patient:yes … eh … Monday … eh … dad … Peter Hogan and dad … hospital. Er … two … er … doctors … and … er … thirty minutes … and ... er … yes … hospital. And … er … Wednesday … Wednesday. Nine o’clock. And … er … Thursday, ten o’clock … doctors … two … two … doctors… and … er … teeth … fine. E:Not exactly your teeth … your g- P:Gum … gum … E:What did they do to them? P:And er … doctor and girl … and er … and er gum … Goodglass 1993: 107

11. Some features of agrammatism • Telegraphic speech • Short utterances • Omission of grammatical functors • Relative abundance of substantives • Verbs are uncommon, rare in some patients • When present, uninflected or –ing form • For French aphasics, infinitive form • Use of word order is generally spared • Comprehension is impaired for complex sentences

12. Verbal short-term memory deficit(in Broca aphasia) • Patients can readily point to individual objects or body parts named by the examiner • But when asked to point to the same items in a specific sequence they often fail at the level of only two or three items Benson & Ardila 124 How to explain?

13. Problems in the study of agrammatism • Must be distinguished from paragrammatism • Grammatical aberrations – even among Broca aphasics – vary from patient to patient • Linguistics has not (yet) provided clear answers to important basic questions: • What normal grammatical functions are • How they operate

14. Syntax • First, we need to dispel the notion that syntax is one capacity, that can be lost (or spared) as a unit • Syntax can be understood as a set of constructions • Learned by children (and others) one by one • Like vocabulary • Some can be lost, others spared, in aphasia • It is a label of the grammarian for multiple things • Word order is often spared in Broca’s aphasia while a lot of syntax is lost

15. Stability of word order in agrammatism • Agrammatic patients can usually handle word order in both production and comprehension • Evidence (comprehension) • Passive sentences misconstrued • The horse was kicked by the dog • Broca’s aphasic: horse as kicker • Passive marker not apprehended • Canonical word order guides the interpretation • Possibly aided by conceptual knowledge

16. Reading and writing in agrammatism • Agrammatic difficulties are also seen in • Oral reading • Writing to dictation • Repetition • But: • Some patients are agrammatic in speech but not in writing (Goodglass 1993: 110) • Somecan repeat correctly • How to explain? • Menn & Obler (1990) describe some patients who are less agrammatic in oral reading than in spontaneous speech (Goodglass 1993:111)

17. Variation among agrammatics (Goodglass 1993:107) • Syntax and morphology (study of agrammatic French aphasics) • Some patients have fairly good syntax but defective morphology • Some patients have fairly good morphology but defective syntax • Both types of patients fail to use inflected verb forms • Gleason et al. observations (1975) • Some patients use –s plural marker but not articles • Other patients use articles but not –s plural marker

18. Loss of the use of relational markers in receptive agrammatism (118) • E.g. father’s sister • Ex: Is “my father’s sister” a man or a woman? • Patient answers randomly • Unable to grasp the relational function of –’s • Command given in testing: • Ex: Touch the comb with the pencil • Patient may touch the pencil with the comb • Perhaps picks up comb because the word comb comes first in the instruction • Locative relations somewhat less fragile • in back of/in front of, over/under, before/after

19. Linguistic structure in the cortex:What we learn from agrammatism • Agrammatism is generally associated with Broca’s aphasia • Therefore, the grammatical skills lost in Broca’s aphasia must be supported at least in part by either • Broca’s area, or • Area(s) adjacent to Broca’s area • In other words: There must be something in or near Broca’s area that is essential for correct grammatical production • And grammatical comprehension– • Receptive agrammatism

20. Receptive processing in Broca’s aphasia? • Problem: • Broca’s area is in frontal lobe • Frontal lobe is supposed to be for motor production • Motor production is top-down processing • Receptive functions involve bottom-up processing • Usually found in posterior cortical areas • Comprehension involves receptive processing • in frontal lobe? • Bottom-up (receptive) processing in frontal lobe?

21. Receptive agrammatism in Broca’s aphasiaTwo avenues to explanation • The role of short-term memory, and Broca’s area in short-term memory • Maybe the frontal lobe can have receptive function • To explore this possibility we must first examine the phenomenon of imagery

22. For perspective, A related problem: Imagery • Types of sensory imagery • Visual • Auditory • Somatosensory • Cf. Motor imagery

23. Visual Imagery • Visual images of people, buildings, etc. • What is a visual image? • What does it consist of? • Is it a little picture in the brain? • If so, where are the eyes to see it? • What is it drawn on? • Where is the visual perception system to interpret it? • If not, what?

24. Auditory Imagery • Auditory images of words, music, etc. • We can hear things in our heads • What is an auditory image? • What does it consist of? • Sound? • There is no air inside the head to vibrate • What hears it? • Little ears inside the head?

25. How Imagery Operates • It’s unlikely that visual imagery uses some mechanism independent of that for vision • Therefore, it must use (some of) the same neural connections used in perception • For visual imagery, pathways in the occipital lobe • For auditory imagery, pathways in the temporal lobe • For tactile imagery, pathways in the parietal lobe • Imagery is activation of some of the same neural pathways that get activated upon receiving input from sense organs

26. Anatomical consequences • Consequences of imaging explanation • Top-down processing in perceptual areas • Perceptual pathways must have parallel pathways of opposite direction • Why are imagined scenes less vivid than those resulting from input to the eyes?

27. Bidirectional Processing • Imagery requires top-down processing • Using pathways that typically operate bottom-up • Therefore, perceptual pathways must generally be bidirectional • Anatomical evidence supports the hypothesis • Reciprocal pairs of cortico-cortical axons

28. Bidirectional Connections • Most corticocortical connections are bidirectional • An established finding from neuroanatomy • It’s not because the connecting nerve fibers (axons) are themselves bidirectional • It’s because we find different but roughly parallel fibers going in opposite directions

29. Bidirectional Processing in Frontal Lobe? • Frontal lobe processing: typically top-down • But there is a large amount of uniformity in cortical structure • Hypothesis: Bottom-up processing also in frontal lobe • From perceptual (i.e. posterior) areas to locations in frontal lobe • We already have seen evidence: the arcuate fasciculus

30. Bidirectional connections in frontal lobe • Would explain how Broca’s area is involved in receptive grammatical processing • Would account for the finding that interpretation of prepositions and verbs is a frontal lobe function • Finding from the study of agrammatism

31. Attempts to explain agrammatism • Many theories have been proposed • Cf. Goodglass 1993:111ff • Some intriguing ideas • Loss of relational use of words (Jakobson, Luria) • Difficulty with markers of such relationships • Impairment of inner speech (Luria) • Hence, impairment of auditory working memory • Difficulty with unstressed words (Goodglass, Kean) • Substantive words are commonly stressed • Functors are generally unstressed

32. Caution in interpreting • Agrammatism may not be just one phenomenon • Syntax is not one structure but several • All agrammatics and probably all Broca’s aphasics are deficient in use of verbs • Other phenomena of agrammatism show more variability • The problem (or part of the problem) may not be grammar as such: • Syntax revolves around verbs • So maybe the problem is with the verbs • Short-term memory – the inner speech loop • Phonology: stressed vs. unstressed words

33. Phonological factors • Function words are (in general) unstressed • Maybe the difficulty is in production of unstressed words • Intriguing finding of Goodglass et al. • (See Goodglass 1993:114-115) • Function words • More likely to be produced after a stressed word • But almost never produced initially • Production starts with stressed word • Even when the patient is asked to repeat: • Open the door > Open the door • Patient repeats correctly, including ‘the’ • The door is open > Door is open • Same patient omits ‘the’ in repetition

34. More evidence on relational markers (119f) • Grammatical particles that do not mark relations are exempt from omission • and • Japanese clause-final particles • Emphatic yo • Question marker ka • Confirmation-seeking particle ne • Verbs always have a syntactic implication • I.e. relationship to one or more nouns • Menn & Obler: Impairment affecting grammatical elements that mark relationships within the sentence

35. Nouns and Verbs:Back Brain & Front Brain (?) • “A Neurolinguistic Universal” –Eliz. Bates • Verb deficit in Broca’s aphasia • Noun deficit in Wernicke’s aphasia • Suggests that • Verbs are represented in frontal lobe • Nouns are represented in or near temporal lobe – angular gyrus and/or supramarginal gyrus) and/or middle temporal gyrus • Supported by semantic considerations • Prototypical nouns represent perceivable objects • Prototypical verbs represent activities of body

36. Proceed with Caution! • We already know that a noun or a verb has a complex cortical representation • Therefore it is not in a single location • The representation is complex, therefore is distributed among multiple locations • So what are we talking about when we talk about nouns and verbs having a location? • This problem will require further investigation • Meanwhile, smthg to think about

37. Verb deficit and agrammatism: Why? • Syntactic hypothesis • Verbs are by their nature syntactically complex • Nouns are not complex – they can stand alone • Semantic hypothesis • Verbs represent processes and processes are managed by the frontal lobe • Nouns represent things, and things are known mainly through perception, which is managed by the occipital, temporal, and parietal lobes

38. Subdivisions of Broca’s area • Broca’s area includes two different (but adjacent) Brodmann areas • BA 44 – Pars Opercularis • BA 45 – Pars Triangularis • (Some people also include the Pars orbitalis, just inferior to the pars triangularis)

39. Frontal Operculum • Operculum: little cover • The part of the frontal lobe that covers (part of) the Sylvian fissure and anterior insula • Adjacent to and inside the anterior portion of Sylvian fissure • Opposite it (across Sylvian fissure) in temporal lobe is the temporal operculum

40. Subdivisions of Broca’s area • Another view

41. Broca’s area and Broca’s aphasia • Broca’s original patient • Lesion was extensive • Not just Broca’s area but also • Adjacent areas • Subjacent white matter • A tradition has followed Broca • Broca’s area held responsible for symptoms of Broca’s aphasia • Confounding factor: • Broca’s area is usually only part of the area of damage in Broca’s aphasia

42. Broca’s area and grammarConclusions • Evidently, Broca’s area or an area adjacent to Broca’s area is responsible for • Not only phonological productions, but also • Critical grammatical functions • Both in production and in understanding • Understanding of complex syntax • At least some portion/aspect of verb processing • Also, prepositions and other “function words” • But not non-relational “function words” (‘and’) • The situation is evidently very complicated and not well explained

43. end