Aphasia: Symptoms and Syndromes Ling 411 – 04

Simple Functions / Complex Functions A question came to me in class when you mentioned that localization does not work for complex functions (e.g. rats navigating mazes), because the brain can compensate with other brain areas. It seems to me that "understanding speech“, localized in Wernicke's area, is actually a pretty complex process...how is simplicity/complexity determined? This is a general question, but I'm interested in the implications of this question to also the Broca's area and any other relevant areas. Either a general explanation or a point in the right direction to what sort of researchers work I want to look at would be greatly appreciated. Thanks! Halle

Simple Functions / Complex Functions Simple function Complex function

Phonological Production / Speaking  Speaking is a complex process Therefore, involves multiple areas  Phonological production is a simple process Broca’s area  together with parts of primary motor area and subcortical areas  Other processes in speaking (other than phonological production)

Phonological Recognition / Understanding  Understanding speech is a complex process Therefore, involves multiple areas  Phonological recognition is a simple process Wernicke’s area  together with primary auditory area and subcortical areas  Other processes in understanding (other than phonological recognition)

Doubts about Wernicke’s Area Steven Pinker: Wernicke’s area …was once thought to underlie language comprehension. But that would not explain why the speech of these patients sounds so psychotic. The Language Instinct (1994) Friedemann Pulvermüller: …patients with Wernicke’s aphasia have difficulty speaking…. These deficits are typical…and cannot be easily explained by assuming a selective lesion to a center devoted to language comprehension. The Neuroscience of Language (2002)

Erratic Speech in Wernicke’s Aphasia “I feel very well. My hearing, writing been doing well. Things that I couldn’t hear from. In other words, I used to be able to work cigarettes. I didn’t know how…. Chesterfeela, for 20 years I can write it.” From Harold Goodglass Understanding Aphasia (1993)

Lessons from Carl Wernicke Carl Wernicke: Primary functions alone can be referred to specific areas…. All processes which exceed these primary functions…are dependent on the fiber bundles, that is, association. Aphasia Symptom Complex (1874) Any higher psychic processes exceeding these primary assumptions cannot be localized but rest on the mutual interaction of these fundamental psychic elements which mediate their manifold relations by means of the association fibers. Recent Works on Aphasia ( )

Wernicke and Connectionism Kandel, Schwarz, and Jessel: “ …Wernicke proposed (1876) that only the most basic mental functions, those concerned with simple perceptual and motor activities, are localized to single areas of the cortex, and that more complex intellectual functions result from interconnections between several functional sites. In placing the principle of localized function within a connectionist framework, Wernicke appreciated that different components of a single behavior are processed in different regions of the brain. He thus advanced the first evidence for the idea of distributed processing, which is now central to our understanding of brain function.” Essentials of Neural Science and Behavior (1995:13)

Basic functions and complex functions  Phonological recognition is a basic function  It is located in Wernicke’s area along with, perhaps, the area intermediate between primary auditory area and W’s area  Speaking is a complex function It is a cooperative effort of several areas, including Broca’s area and Wernicke’s area Phonological recognition is a necessary component of speaking

Wernicke’s Area and Speaking  Phonological images guide speech production  Phonological recognition monitors production  Compare.. Painting without visual perception Playing a piano without auditory perception  Conclusion: Of course phonological recognition (i.e. Wernicke’s area) plays a role in speech production

Pulvermüller’s Statement …patients with Wernicke’s aphasia have difficulty speaking…. These deficits are typical…and cannot be easily explained by assuming a selective lesion to a center devoted to language comprehension. The Neuroscience of Language (2002)

Paraphrasing Pulvermüller Altered quote: …patients with damage to the occipital lobe have difficulty drawing pictures…. These deficits are typical…and cannot be easily explained by assuming a selective lesion to a center devoted to visual perception. …patients with Wernicke’s aphasia have difficulty speaking…. These deficits are typical…and cannot be easily explained by assuming a selective lesion to a center devoted to language comprehension. The Neuroscience of Language (2002)

Aphasic Symptoms Varieties of language deficits Inferences from language deficits Problems of interpretation

Some speech of a Broca aphasic Examiner: What brought you to the hospital? Patient: Yes... Monday... Dad, and Dad... hospital, and... Wednesday, Wednesday, nine o'clock and... Thursday, ten o'clock... doctors, two, two... doctors and... teeth, yah. And a doctor... girl, and gums, and I (Patient was trying to explain that his father had brought him into the hospital on Wednesday to have some work done on his teeth.)

Speech production: a complex process  The motor realization of speech involves the smooth coordination of a number of separate neuromuscular systems  Sensory feedback and monitoring enter this process at many points  Coordination Activity of different systems must be coordinated Planning of neural activity has to precede low- level activation by varying amounts of time Lead time from neural activity to muscle activity differs from system to system (Goodglass, 62)

More, from a (different) Broca’s apasic "Me... build-ing... chairs, no, no cab-in-ets. One, saw... then, cutting wood... working..."

Attempt to describe “cookie theft” picture (Broca’s aphasic) Cookie … Okay … the cookie jar … and the kid is a … uh … stool … bump … the skool … skool … uh … hurt … and girl … I don’t know … Goodglass 139

Agrammatism in Broca’s aphasia 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 105)

Some speech of a Wernicke aphasic Examiner’s question: Who lives at home with you? Patient: My wife, she goes her work to work on it but her heffle is all about it. On testing for comprehension of single words, patient can point to only one of six objects that are named for him. His attempts to write result in a jargon similar to his speech. Goodglass 2

Another Wernicke aphasic Attempt to describe a picture showing a young woman standing with books in her arms, portrayed in a farm scene with family members engaged in farm labor: “Well, all I know is, somebody is clipping the kreples and some wha, someone here on the kureping arm … why I don’t know.”

Examples of anomia I gave him a … Oh God! I know it! Why can’t I say it? I lost my … I keep my money in it.

Some speech of a conduction aphasic Patient: I came into the hospital for some tecs... Some secs … tesk … T E S … tests. Goodglass 73

Paraphasia  Verbal paraphasia Use of one word instead of the intended one Usually, same part of speech  Phonemic paraphasia Unintended phonemes or sequences of phonemes “paker” for “paper”, “sisperos” for “rhinoceros”  Neologistic paraphasia “tilto” for “table” See, my refkid is … are bad. Oh, my cathopes noe too good. Well, my gupa wasn’t too good. (85)

Examples from a picture-naming test PatientTarget WordResponse Mr. W.stethoscopetelescope – not right (Broca)asparaguscarrot – no pinwheelkite nozzlehose – no Father L.seahorsemandarin (Wernicke)globeatlas stethoscopeoctopus – no* hourglassit’s a weather * A picture of an octopus had been presented earlier in the test ( Goodglass 78)

Phonemic paraphasia in a conduction aphasic Target Word(picture) Response__________ Dartcart … part … chart Broombroo … croo … broom Scrollscrip… screl … scrit … roll it up … sholl … scroll Benchfence … park bence … bench Pinwheelpan.. P E A … peanwheel … pinwill … penwhale … pinfin … no pinwheel (Goodglass 88)

Perisylvian Aphasic Syndromes

The most common perisylvian aphasias in order of frequency of occurrence 1. Broca Aphasia 2. Wernicke Aphasia 3. Conduction Aphasia

Characteristics of Broca Aphasia  Non-fluent speech  Sparse verbal output  Poorly articulated  Consists of short phrases  Produced with effort  Mostly nouns and other content words  Deficiency or absence of inflectional affixes  Absent or deficient syntactic structure

Word classes in Broca aphasia  Mostly nouns  Some adjectives  A few verbs Generally uninflected or in ‘-ing’ form  Function words few or non-existent

Comprehension in Broca aphasia  Generally good  More or less impaired for syntactically complex sentences  Difficulty in comprehending the same words that are omitted in speech production Also, difficulty with repetition of these words  Difficulty understanding relational words E.g. bigger/smaller, up/down, within/without

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

Conduction Aphasia  Originally postulated by Wernicke  Good comprehension  Poor repetition Many phonemic paraphasias  Defective production Many phonemic paraphasias  Different subtypes Different areas of damage  5 to 10 percent of all aphasias

Pronunciation deficits  Broca’s aphasia Correct phonemes, faulty articulation The problem is more phonetic than phonemic  Conduction aphasia Correct articulatory realization of phonemes But incorrect phonemes The problem is phonemic, not phonetic  I.e., phonemic paraphasia  (B&A call it ‘literal paraphasia’) How to explain?

Areas of damage in conduction aphasia  Different areas for different subtypes  Arcuate fasciculus  Left parietal lobe Goldstein: ‘central aphasia’  Probably the supramarginal gyrus (?) Lower postcentral gyrus  Luria: ‘afferent motor aphasia’  Insula  More than one of these areas can be damaged in individual cases

Coronal section, showing Sylvian fissure, insula, etc.

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