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Lexical Access: Generation & Selection. Today’s Main Topic. Listeners as active participants in comprehension process Model system: word recognition. Outline. Speed & Robustness of Lexical Access Active Search Evidence for Stages of Lexical Access Autonomy & Interaction. Outline.
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Today’s Main Topic • Listeners as active participants in comprehension process • Model system: word recognition
Outline • Speed & Robustness of Lexical Access • Active Search • Evidence for Stages of Lexical Access • Autonomy & Interaction
Outline • Speed & Robustness of Lexical Access • Active Search • Evidence for Stages of Lexical Access • Autonomy & Interaction
The mental lexicon sport figure sing door carry turf turtle gold turk turkey turn water turbo turquoise turnip turmoil
How do we recognize words? • The Simplest Theory • Take a string of letters/phonemes/syllables, match to word in the mental lexicon • (That’s roughly how word processors work) • …is it plausible?
Word Recognition is Fast • Intuitively immediate - words are recognized before end of word is reached • Speech shadowing at very brief time-lags, ~250ms (Marslen-Wilson 1973, 1975)
Lexical Access is Robust • Succeeds in connected speech • Succeeds in fast speech • Survives masking effects of morphological affixation and phonological processes • Deleted or substituted segments • Speech embedded in noise
But… • Speed and robustness depends on words in contextsentence --> word context effects • In isolation, word recognition is slower and a good deal more fragile, susceptible to error • …but still does not require perfect matching
Questions • How does lexical access proceed out of context? • Why is lexical access fast and robust in context? • When does context affect lexical access? • does it affect early generation (lookup) processes? • does it affect later selection processes?
Additional Context Effects • Word context affects phoneme identification…word --> phoneme context effects
Phoneme Restoration • The _eel had a broken axleThe _eel on the orange was hard to cut(Warren 1970) • Phoneme restoration effects are stronger(i) in words than non-words(ii) later in words(iii) in strongly biasing contexts
Phoneme Monitoring • press the button as soon as you hear a ‘b’ • “in the yard was a large group of twittering birds”“cat, dog, horse, rabbit …” • Monitoring is facilitated by context
Perceptual Boundaries DA TA
Perceptual Boundaries DASK TASK (Ganong 1980)
Perceptual Boundaries DASK TASK (Ganong 1980)
Perceptual Boundaries DASH TASH (Ganong 1980)
Perceptual Boundaries DASH TASH (Ganong 1980)
Reaction Time Paradigms • Lexical Decision • Priming
List 1sicklecathartic torrid gregarious oxymoron atrophy List 2parabola periodontist preternatural pariah persimmon porous Looking for Words
List 1sicklecathartic torrid gregarious oxymoron atrophy List 2parabola periodontist preternatural pariah persimmon porous Looking for Words Speed of look-up reflects organization of dictionary
Looking for Words DASH
Looking for Words RASK
Looking for Words CURLY
Looking for Words PURCE
Looking for Words WINDOW
Looking for Words DULIP
Looking for Words LURID
Looking for Words PRESSULE
Looking for Words DOCTOR
Looking for Words NURSE
Looking for Words • Semantically Related Word Pairsdoctor nurse hand finger speak talk sound volume book volume
Looking for Words • In a lexical decision task, responses are faster when a word is preceded by a semantically related word • DOCTOR primes NURSE • Implies semantic organization of dictionary
Outline • Speed & Robustness of Lexical Access • Active Search • Evidence for Stages of Lexical Access • Autonomy & Interaction
Active Recognition • System actively seeks matches to input - does not wait for complete match