Language Ref: Banich pp

Classical Model of Language 1.Predicted Patterns Never "Absolute“ 2.Symptoms can dissociate BUT:

Multi-component view Anterior (around Broca’s area): Articulation of speech Articulation of speech Understanding syntactic relationships Understanding syntactic relationships Posterior (around Wernicke’s area): Retrieval of phonemes for production Retrieval of phonemes for production Selection of words for production Selection of words for production Access to semantic info about words Access to semantic info about words All of these can become selectively impaired:

Examples of Components Articulatory Planning: Anterior (overlaps Broca’s area) Anterior (overlaps Broca’s area) Damage: halting, effortful, distorted speech Damage: halting, effortful, distorted speech Retrieval of Phonemes: Posterior (nr. Wernicke’s area) Posterior (nr. Wernicke’s area) Damage: good articulation, but can’t recall word sounds, make phonemic paraphasias Damage: good articulation, but can’t recall word sounds, make phonemic paraphasias e.g. Turtle: um.. tornet, no that's not right.... (etc)... turking.. that's wrong what's the end part?…

Examples of Components Access to Semantic Info. Posterior (overlaps Wernicke’s area) Posterior (overlaps Wernicke’s area) Damage: P can’t understand word meanings, produces semantic paraphasias: Damage: P can’t understand word meanings, produces semantic paraphasias: e.g. Turtle: That’s some kind of animal, isn’t it. A seal, is it?

Anterior vs. posterior areas Anterior regions are involved in: Generation of new combinations e.g.sentences (novel combinations of words) articulation (must be done afresh each time) Posterior language regions (LH) are involved in: Storage/retrieval of familiar, well-learned relationships e.g.phoneme sequences of common words meanings of common words

Reading Ref: Banich: Visual language, pp (up to writing)

Coltheart’s Two Route Model Lexicon: word sounds and meanings Grapheme-phonemeConversion e.g. sh -> /s/ Print Pronunciation Grapheme-phoneme (or phonological) route Lexical (or direct) route

Coltheart’s Two Route Model Lexical route: Recognise whole word Recognise whole word Look up in lexicon Look up in lexicon Good for known words (not unfamiliar words) Good for known words (not unfamiliar words) Grapheme-phoneme route: Identify graphemes (e.g. b, k th, sh)Identify graphemes (e.g. b, k th, sh) Convert each grapheme to a phonemeConvert each grapheme to a phoneme Good for regular words (e.g. cat) but not irregular words (e.g. yacht)Good for regular words (e.g. cat) but not irregular words (e.g. yacht)

Dyslexia Two major types of acquired dyslexia: Phonological dyslexia = Damage to grapheme-phoneme route Surface dyslexia = Damage to lexical route Acquired Dyslexia = reading impairment resulting from damage to brain (cf. Developmental dyslexia = reading impairment present throughout development)

Phonological dyslexia Grapheme-phoneme route damaged: can’t read nonwords, unfamiliar words can’t read nonwords, unfamiliar words lexicalisation errors e.g. heef -> beef lexicalisation errors e.g. heef -> beef OK on familiar words: prob. may go undetected OK on familiar words: prob. may go undetected regularity not important (yacht = yet) regularity not important (yacht = yet) Lexicon Grapheme-phonemeconversion Print Pronunciation

Phonological dyslexia kedbem narcug fonlat shidboak doopbirl duspsoaf Tests: PALPA (Psycholinguistic Assessment of Language Processing in Aphasia) -> Nonword reading subtest

Phonological dyslexia Localisation:

Surface dyslexia Lexical route damaged: - can’t read irregular words e.g. yacht, pint. - regularization errors e.g. pint -> /pInt/, busy -> buzzy - regularization errors e.g. pint -> /pInt/, busy -> buzzy One patient, when given the word "listen" to read, pronounced it "Liston", then exclaimed "Liston, the boxer!“ - OK on regular words, even unfamiliar ones Lexicon Grapheme-phonemeconversion Print Pronunciation

Surface dyslexia Tests: PALPA spelling-sound regularity subtest effort (R)pretty (E)middle (R)barge (R) break (E)envy (R)blood (E)bowl (E) plank (R)navy (R)ceiling (E)iron (E) cough (E)context (R)rub (R)routine (E) bury (E)yacht (E)flannel (R)tail (R) wolf (E)island (E)wedding (R)chicken (R) colonel (E)luck (R)smog (R)nerve (R)

Surface dyslexia Localisation:

Double Dissociation Irregular words Unfamiliar words Phonological dyslexics Surface dyslexics GoodPoor Good

Other types of dyslexia Surface and Phonological are examples of Central dyslexias (a third subtype to come)Surface and Phonological are examples of Central dyslexias (a third subtype to come) Peripheral dyslexias: visual analysis of wordPeripheral dyslexias: visual analysis of word e.g. letter-by-letter reading: can't perceive whole word

Deep Dyslexia Another kind of “central dyslexia” Another kind of “central dyslexia” Can't read unfamiliar words (like in phonological dyslexia)Can't read unfamiliar words (like in phonological dyslexia) BUT also have problems with known words (esp. function words, abstract words)BUT also have problems with known words (esp. function words, abstract words) Complex errors: semantic e.g. affection -> love visual e.g. science -> scene Complex errors: semantic e.g. affection -> love visual e.g. science -> scene

Deep Dyslexia sour:bad thirst:thirsty lamp:lap clothing:clothes insult:imbecile? no... decent:I know what it is, but I can't say it capacity:absence applause:its clapping Reading by Patient BM

Deep Dyslexia Both "routes" seem affected: Both "routes" seem affected: - can't use grapheme-phoneme route - also unable to reliably access lexicon directly Sometimes partial access:Sometimes partial access: Patient AR: Ostrich: "I get the impression of an animal“ Localisation: Extensive damage to LH

Explanations for Deep Dyslexia 1. Imperfect Lexicon: P can't use grapheme-phoneme route at allP can't use grapheme-phoneme route at all therefore, must rely on what's left of lexical routetherefore, must rely on what's left of lexical route errors occur when word not available in lexiconerrors occur when word not available in lexicon evidence : similar errors in other language tasksevidence : similar errors in other language tasks

Explanations for Deep Dyslexia LH so damaged, P relies entirely on RHLH so damaged, P relies entirely on RH RH word knowledge limitedRH word knowledge limited Evidence : increased RH activity in dyslexics (fMRI)Evidence : increased RH activity in dyslexics (fMRI) Anterior production areas RH lexicon (intact but limited) LH lexicon (damaged) CAT 2. “Right Hemisphere Reading":