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Cognitive Neuroscience. The four components of word knowledge: Evidence from deficits. Word Knowledge. What do we know when we know a word? meaning ( semantics ) grammatical properties (gender, grammatical category, etc.) ( syntax/morphology ) sound ( phonology ) spelling ( orthography ).
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Cognitive Neuroscience The four components of word knowledge: Evidence from deficits
Word Knowledge What do we know when we know a word? • meaning (semantics) • grammatical properties (gender, grammatical category, etc.) (syntax/morphology) • sound (phonology) • spelling (orthography)
Word Knowledge We can categorize our word knowledge in this way, but does the brain do so? That is, although these kinds of information are certainly stored in the brain, are the distinctions respected in terms of the neural instantiation? How can we know????? • different neural geographies revealed by selective impairment and/or selective activation
Word Knowledge Noun, plural +s Luxurious sea-going vessel Y-A-C-H-T /y a t/
Semantics/Phonology • R.G.B. • Caramazza & Hillis (1990) • 62-year-old, right handed • Retired personnel manager, high-school education • CVA 4 years prior to investigation • Left fronto-parietal infarct • Dense hemiplegia
% correct Aud word/pix match 100 Vis word/pix match 100 Aud/Vis word match 100 Oral reading 67 Oral naming-pix 62 Oral naming-tactile 64 R.G.B.
R.G.B. stimulus reading definition RECORDS radio you play’em on a phonograph….can also mean notes you take and keep GREY blue color of hair when you get old SUBWAY bus you ride on them from one area to another…they have’em in NY and now we have one in Baltimore. Goes on tracks underground QUILL feather they’re long an dhave a point…animals, porcupines have them DOLLAR money a bill… a hundred cents MOCCASINS shoes Indians used to wear them CITRUS apple no, kind of fuit you get down south…like an orange
Word Knowledge Luxurious sea-going vessel /y a t/
Syntax/Phonology Dante Badecker, Miozzo & Zanuttini (1993) • Male, 24-yrs-old, 8 years of education • Suspected meningoencephalitis • Hypodensity in fronto-temporo-parietal regions • Fluent speech w/ word finding difficulties, good comprehension
Anomia or tip-of the-tongue state • A raised platform on which a speaker may sit or stand • DAIS
Dante Task: -name 100 pix & 100 sentence completions -when in an anomic state, asked to make a forced choice judgments of: grammatical gender (masc/fem) first letter (T/D) word length XXXX/XXXXXX last letter (S/M) rhyming word
Dante: Results Correct naming 56%, with 88 anomic responses Accuracy for forced choice queries on anomic trials: Gender 98% Word length 50% First letter 53% Last letter 47% Rhyming word 48%
Word Knowledge Noun, plural +s Luxurious sea-going vessel /y a t/
Phonology/ OrthographyGood phonology, poor orthography (and vice versa) RGB (Caramazza & Hillis, 1990) Aud word/pix match 100 Vis word/pix match 100 Aud/Vis word match 100 Oral reading 67 Oral naming-pix 62 Oral naming-tactile 64 Written naming* 94% Writing to dictation* 94% *no semantic errors
Phonology/ Orthography • Good phonology, poor orthography (and vice versa) RCM (Hillis, Rapp & Caramazza, 1999) Aud word/pix verification 100% Vis word/pix verification 100% Oral reading 97% Oral naming-pix 100% Written naming* 53% Writing to dictation* 47% *primarily semantic errors
Word Knowledge Noun, plural +s Luxurious sea-going vessel Y-A-C-H-T /y a t/
Dissociable aspects of word knowledge • Knowledge types are represented in neural substrate in a manner such that they can be dissociated • Localization?