I. Classifications of Aphasia II. Laterality III. Varieties of Anomia IV. Reading and Writing

1. Ling 411 – 06 I. Classifications of AphasiaII. LateralityIII. Varieties of AnomiaIV. Reading and Writing

2. Problems of classification • Different aphasics almost never share the same set of symptoms (Benson&Ardila 111) • Variations “are so plentiful as to be the rule” (B&A 117) • A single type of aphasia may have distinctly different loci of pathology (B&A 117) • Conduction aphasia (117) • Parietal lobe • Arcuate fasciculus • Transcortical motor aphasia (118) • Differing interpretations of sets of symptoms • Different approaches to classification

3. Wide variation in classification schemes • Influential ones in history of aphasiology: • Wernicke-Lichtheim 1881, 1885 • Head 1926 • Goldstein 1948 • Luria 1966 • Benson 1979 • Benson & Ardila 1996 • Damasio 1998 • But .. • All recognize just a small number of basic syndromes • Most of the variation in classification schemes is just terminological (Benson&Ardila 120)

4. Damasio’s Classification (1998:34ff) • Wernicke’s aphasia • Broca’s aphasia • Conduction aphasia • Transcortical sensory aphasia • Transcortical motor aphasia • Global aphasia • Anomic aphasia • Alexia • Pure word deafness • Atypical aphasias

5. The 1996 Benson & Ardila Classification(B&A: 119) Pre-Rolandic Post-Rolandic Peri- Sylvian Extra- Sylvian Not included in above scheme: (1) Problems with reading & writing (2) Anomic aphasia (3) Global aphasia

6. Features of the 1996 B&A Classification(B&A: 119) • Based on two anatomical dichotomies: • Pre- vs post-Rolandic • Perisylvian vs. extrasylvian • For every type, two subtypes • But the two subtypes can be just two ends of a continuous scale, not distinct subtypes • Alternatives to usual terms: • “Extrasylvian” instead of “transcortical” • “Broca” instead of “Broca’s” • ‘Wernicke” instead of “Wernicke’s”

7. A major anatomical-functional dichotomy:Front (anterior) vs. Back (posterior) • Front • Action and planning of action • Process oriented • Back • Perception • Perceptual integration • Object oriented

8. Damasio Wernicke’s aphasia Broca’s aphasia Conduction aphasia Transcortical sensory aph. Transcortical motor aph. Global aphasia Anomic aphasia Alexia Benson & Ardila Wernicke aphasia Broca aphasia Conduction aphasia Extrasylvian sensory aph. Extrasylvian motor aph. Global aphasia Anomic aphasia Wernicke II or Posterior extrasylvian Damasio vis-à-vis Benson & Ardila

9. Fluent Receptive* Sensory Posterior Non-fluent Expressive* Motor Anterior Front-Back dichotomy and aphasia: Alternative terms/emphases *But: (1) Very few aphasic patients are completely free of receptive difficulties (2) Virtually no aphasic is entirely without expressive problems (B&A 112)

10. Broca’s aphasia Transcortical motor aphasia Wernicke’s aphasia Conduction aphasia Transcortical sensory aphasia Alexia Pure word deafness Damasio’s Categories asAnterior vs Posterior Aphasias(Or: Pre-Rolandic vs Post-Rolandic) Anterior Posterior Others: Global Aphasia: Both anterior and posterior Anomic aphasia: Can be either or both Atypical aphasias

11. Cerebral dominance for language • Linguistic abilities are subserved by the left hemisphere in about 97% of people • 99% of right-handed people • But this is just a first approximation

12. More refined look • Some information is bilaterally represented • Highly entrenched items • Initial consonants of high-frequency words (?) • Some people have more bilateral representation than others • Women and left-handers tend to have more bilateral representation than men and righties • Pitch, intonation, and other prosodic features subserved by RH • Semantic information is in both LH and RH • But different aspects of semantic information • Metaphor, irony, sarcasm, pragmatic features, inferencing, subserved by RH

13. Left dominance for language in left-handers • Wada test (Milner 1975), on left-handers • 69% aphasic after injection of left brain • 18% aphasic after injection of right brain • 13% aphasic after injection on each side Goodglass 1993:57

14. Right dominance for language in right-handers • Crossed aphasia: Term for right-handers who suffer aphasia after RH injury • Incidence of crossed aphasia is estimated at 1% Goodglass 1993:58

15. The genetics of laterality • Matings of left-handed parents produce no more than about 50% left-handed offspring • Annett’s theory (1985) • A single right-shift gene (rs+) • If rs++, right-handed (LH dominant) • If rs+-, right handed (LH dominant) • If rs-- (right-shift gene absent).. • Can go either way • Depends on environment, experience • 50% probability of becoming left-handed

16. Left hemisphere Analytical thinking Digital Heightened contrast Proof Right Hemisphere Holistic thinking Analog Fuzzy boundaries Hunches, intuition Left hemisphere vs. right hemisphere Question: What anatomical differences are responsible?

17. Separated right and left hemispheres • Cutting corpus callosum separates them • Isolated RH: • Limited one-word reading comprehension • Some grasp of meanings • But unable to make judgments about sound • Isolated LH: • Awareness of both sound and meaning

18. Corpus Callosum(revealed by excision of top of right hemisphere) Corpus Callosum

19. Semantic categories:Varieties of anomia

20. 2 Cases of Rapp & Caramazza (1995) • E.S.T. (901b)– Left temporal damage • “Meaning spared, couldn’t say the word”: R&C • J.G. (902a)– Left posterior temporal-parietal • Meaning spared, couldn’t spell the word correctly, but phonological recognition okay Cf. Rapp & Caramazza, Disorders of lexical processing and the lexicon (1995)

21. Patient E.S.T. (Rapp&Caramazza 1995:901b) • Left temporal damage • Shown picture of a snowman • Unable to name it • “It’s cold, it’s a ma… cold … frozen.” • Shown picture of a stool • “stop, step … seat, small seat, round seat, sit on the…” • Shown written form ‘steak’ • “I’m going to eat something … it’s beef … you can have a [së] … different … costs more …” • What can we conclude?

22. Assessment of E.S.T. by Rapp & Caramazza • Responses of E.S.T. indicate awareness of the meanings (SNOWMAN, STOOL, STEAK) • Therefore, “meaning is spared” (acc. To R&C)

23. Warning: Proceed with caution • The assumption of Rapp&Caramazza is easy to make • I.e., thatmeaning (conceptual information) is spared • But there’s more to this than meets the eye! • As we have seen, conceptual information is widely distributed • We only have evidence that some of the conceptual information is spared

24. Patient E.S.T. – a closer look • Left temporal damage • Picture of a snowman • “It’s cold, it’s a ma… cold … frozen.” • Picture of a stool • “stop, step … seat, small seat, round seat, sit on the…” • Written form ‘steak’ • “I’m going to eat something … it’s beef … you can have a [së] … different … costs more …” • These are not definitions • This is connotative information • Vague semantic notions about the meanings

25. Compare patient J.G. (902a) • Damage: Left posterior temporal-parietal • Meaning spared, couldn’t spell the word correctly, but phonological recognition okay • digit: • D-I-D-G-E-T • “A number” • thief: • T-H-E-F-E • “A person who takes things” • These are actual definitions

26. The Role of RH in semantics • Conceptual information, even for a single item, is widely distributed • A network • Occupies both hemispheres • RH information is more connotative • LH information more exact

27. Connotative information in RH • Tests on patients with isolated RH resulting from callosotomy • RH has information about (many) nouns and verbs • Not as many as in LH • Semantic information differently organized in RH • Zaidel (1990): “… the right hemisphere is characteristically connotative rather than denotative … . The arcs [of the semantic network] connect more distant concepts … and the organizing semantic relationships are more loosely associative and dependent on experience” (125) Baynes & Eliason, The visual lexicon: its access and organization is commissurotomy patients (1998)

28. Semantic information: E.S.T. and J.G. • Patient J.G. – real definitions • digit: “A number” • thief: “A person who takes things” • Patient E.S.T. – connotative information • snowman: “It’s cold, it’s a ma… cold … frozen.” • stool: “ … seat, small seat, round seat, sit on the…” • steak: “I’m going to eat something … it’s beef … you can have a [së] … different … costs more …”

29. Conclusion about E.S.T. • RH semantic information is intact • LH semantic information is wiped out • Phonological information is spared in both hemispheres • Question: Why can’t the RH semantic information be conveyed to LH phonology?

30. Corpus Callosum(revealed by excision of top of right hemisphere) Corpus Callosum

31. Brain damage and nominal concepts • Access to nominal concepts is impaired in extra-sylvian sensory aphasia • Type I – Damage to temporal-parietal-occipital junction area • I.e., lower angular gyrus and upper area 37 • Poor comprehension • Naming strongly impaired • Semantic paraphasia • Type II –Damage to upper angular gyrus • Variable ability to comprehend speech • Naming strongly impaired • Few semantic paraphasias • Many circumlocutions

32. Conceptual category dissociation I • J.B.R. and S.B.Y. (905b-906a) • Herpes simplex encephalitis • Both temporal lobes affected • Could not define animate objects • ostrich, snail, wasp, duck, holly • Much better at defining inanimate objects • tent, briefcase, compass, wheelbarrow, submarine, umbrella • How to explain?

33. Conceptual category dissociation II • J.J. and P.S. (Hillis & Caramazza 1991) (906-7) • J.J. – left temporal, basal ganglia (CVA) • Selective preservation of animal concepts • P.S. – mostly left temporal (injury) • Selective impairment of animate category P.S J.J.

34. Reading and Writing

35. Alexia and Agraphia • Alexia with agraphia • Reading and writing both impaired • A rare disorder • Patients with both impairments usually also have Wernicke’s aphasia or transcortical sensory aphasia • Alexia without agraphia, a.k.a. pure alexia • Reading impaired, writing okay • Can write spontaneously or to dictation • Some can copy writing but with difficulty

36. Misprint in Antonio Damasio Reading • Antonio Damasio, Signs of Aphasia • P. 38: “As the designation implies, patients presenting alexia with agraphia become unable to read while they continue to be able to write…” • Should be “…alexia without agraphia…”

37. More on patient J.G. • Damage: Left posterior temporal-parietal • Meaning spared, phonological recognition okay, but couldn’t spell the word correctly • digit: • D-I-D-G-E-T • “A number” • thief: • T-H-E-F-E • “A person who takes things” • These spellings are not correct, but..

38. Reading – relating writing to speech Phonological word image Phonemes Letters The “Phonics” route

39. Reading – relating writing to speech Phonological Graphic word image word image Letters The “whole word” route

40. Two pathways for relating writing to speech Phonological Graphic word image word image Phonemes Letters Redundancy?

41. Two pathways for relating writing to speech • The “whole word” route is necessary for • caught • island • sign • The “phonics” route is needed for long unfamiliar words • commissurectomy • prosopagnosia • magnetoencephalography

42. The spelling attempts of J.G.(one more look) • digit: • D-I-D-G-E-T • “A number” • thief: • T-H-E-F-E • “A person who takes things” • J.G. has damaged “whole word” route but intact “phonics” route • Evidence that the two routes are separately represented in the cortex

43. More evidence on phonological and graphic forms • Patient P.W. (905) • Damage: anterior parietal & posterior frontal • Tested on identifying spoken words • [skirt]: “S-O-C-K, skirt • Verbal paraphasia in spelling but not in speech • [brush]: “B-R-U-S-H, comb” • Verbal paraphasia in speech but not in spelling • [knife]: “S-P-O-O-N, fork” • Verbal paraphasia in both modalities • Paraphasias are semantically related

44. Patient D.R.B. (902b-903a) • Left middle cerebral artery infarct • Able to discriminate words and pseudo-words • Either visual or auditory input • Test: Two words – synonyms or not? • For written input, 95% accurate • For spoken input, only 61% accurate • Evidence that representations of written words can have direct connections to semantic information

45. Graphic representation and meaning • The traditional view: speech is primary, writing secondary • History • Development • Might suggest that writing has access to meaning only via phonological representation • But evidence from brain damage indicates that (at least some) written forms have direct access to meaning, independently of phonology

46. Pathway to meaning Conceptual information Phonological Graphic word image word image Phonemes Letters

47. Pathways to meaning Conceptual information Does this pathway also exist? Phonological Graphic word image word image Phonemes Letters

48. Evidence for direct connections between meaning and graphic form • Patient D.R.B. (above) • Judgments of synonymy better for pairs of written words than pairs of spoken words • Patient H.W. (904) • Damage: left parietal and occipital • Tested on identifying written words • Interest: • “bank” • “You go to the bank and put it in and you get more money … not very much now”

49. More evidence for direct connections between meaning and graphic form • Patient R.G.B. (904) • Damage: left frontoparietal • Tested on identifying written words • Records: • “radio” • “You play ‘em on a phonograph … can also mean notes you take and keep” • Understands meaning from written input, but has impaired phonological information or impaired connection to phonological information

50. Phonological-Graphic Connections:The Angular Gyrus The angular gyrus and the white matter below it appear to be uniquely important for all aspects of graphic language that involve its linkage to writing, to spoken language, and to word meaning. Injury to this area disrupts not only the ability to understand the written word, but also disrupts related knowledge such as oral spelling and letter-sound correspondence, and therefore disrupts the ability to write. Harold Goodglass Understanding Aphasia 1993:51