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

Major Language Areas Supramarginal gyrus (Goldstein’s area) Angular gyrus (Geschwinds’s area) Wernicke’s area Exner’s area Broca’s area Superior parietal lobule

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

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

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

Broca’s Aphasia Damage to frontal lobe Largely intact comprehension 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

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?

Subtypes of Broca aphasia 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

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

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

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

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

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

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

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) Some can 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)

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

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

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

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 Comprehension involves sensory processing in frontal lobe? Bottom-up (receptive) processing in frontal lobe?

Receptive agrammatism in Broca’s aphasia Two 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

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

Visual Imagery Visual images of people, buildings, etc. What is a visual image? What does it consist of? Is it a little picture? 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?

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?

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

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?

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

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

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

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

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

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: Short-term memory – the inner speech loop Phonology: stressed vs. unstressed words

Phonological factors Function words are (in general) unstressed Maybe the difficulty is in production of unstressed words Intriguing finding of Goodglass et al. Function words May be produced after a stressed word But almost never produced initially Production starts with stressed word Even with repetition Open the door > Open the door The door is open > Door is open

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

Nouns and Verbs: Back Brain & Front Brain (?) “A Neurolinguistic Universal” –E. 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 Supports what we derive from the proximity principle

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 Rather, a functional web So what are we talking about? The cardinal node of the functional web of a noun The cardinal node of the functional web of a verb

A patient with non-fluent aphasia Patient ROX (McCarthy & Warrington 1985) Impaired production and comprehension of verbs Excellent production and comprehension of nouns Had no difficulty imitating common actions But had difficulty in performing same actions in response to verbal commands E.g., confused open and close In action-naming test, sometimes substituted nouns for verbs or omitted verbs: “chairing” for sitting “The man is a sack of potatoes” for a man carrying a sack of potatoes

Verb deficit and agrammatism: Why? Syntactic hypothesis Verbs are by their nature syntactically complex Nouns are not complex – they can stand alone Semantic hypothesis – using proximity 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

Noun-Verb vis-à-vis Speech & Writing (908b) Patient S.J.D. Written naming of verbs defective But oral naming okay Nouns okay for both writing and speaking Patient H.W. Oral naming of verbs defective But written naming okay Comparable results independently of mode of stimulus – picture naming, reading, writing to dictation (More, next slide..)

Inputs: pictures, oral dictation, reading More on H.W. & S.J.D. Noun-Verb vis-à-vis Speech-Writing (Rapp & Caramazza 908-9) Inputs: pictures, oral dictation, reading Tasks: (1) speaking, (2) writing Example: There’s a crack in the mirror (crack as n.) Don’t crack the mirror (crack as v.) S.J.D. crack as n. correctly produced, both modalities crack as v. correct only in spoken modality H.W. – the opposite modality effect Data from Caramazza & Hillis (1991)

Broca’s Area: A closer look

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)

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

Subdivisions of Broca’s area Another view

Major Language Areas Supramarginal gyrus (Goldstein’s area) Angular gyrus (Geschwinds’s area) Wernicke’s area Broca’s area Superior parietal lobule Brodmann area 37

Left hemi-sphere, showing middle cerebral artery Frontal Operculum

A closer look at 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 only part of the area of damage with Broca’s aphasia

More recent findings Modern imaging methods help Some patients have damage restricted mainly or entirely to just Broca’s area They have less severe symptoms that typically associated with Broca’s aphasia Influential paper: Alexander et al. 1990 Examined Broca patients with different areas of damage Cast doubts on importance of Broca’s area in Broca’s aphasia

Broca’s area and Broca aphasia Maybe it’s not just Broca’s area damage that is responsible for some of the symptoms of “Broca’s aphasia” Maybe some of them result instead from damage to neighboring areas Alexander et al. (1990) propose distinguishing 3 subtypes

Three subtypes in Alexander study Impaired speech initiation Symptom traditionally attributed to transcortical motor aphasia Area of damage: frontal operculum Disturbed articulatory function Area of damage: lower primary motor cortex The classical Broca’s aphasia syndrome More extensive damage

To be continued … (Later)

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