Wednesday, April 08, 2009

The Cohort Model/ NEW LEXICON

The cohort model in psycholinguistics and neurolinguistics is a model of lexical retrieval first proposed by William Marlsen-Wilson in the late 1980s.[1] It attempts to describe how visual or auditory input (i.e., hearing or reading a word) is mapped onto a word in a hearer's lexicon. According to the model, when a person hears speech segments real-time, each speech segment "activates" every word in the lexicon that begins with that segment, and as more segments are added, more words are ruled out, until only one word is left that still matches the input.


The cohort model is based on the concept that auditory or visual input to the brain stimulates neurons as it enters the brain, rather than at the end of a word.[2] This fact was demonstrated in the 1980s through experiments with speech shadowing, in which subjects listened to recordings and were instructed to repeat aloud exactly what they heard, as quickly as possible; Marlsen-Wilson found that the subjects often started to repeat a word before it had actually finished playing, which suggested that the word in the hearer's lexicon was activated before the entire word had been heard.[3] Findings such as these led Marlsen-Wilson to propose the cohort model in 1987.[4]

Under this model, auditory lexical retrieval begins with the first one or two speech segments, or phonemes, reach the hearer's ear, at which time the mental lexicon activates every possible word that begins with that speech segment.[5] The words that are activated by the speech signal but are not the intended word are often called "competitors."[6] As more speech segments enter the ear and stimulate more neurons, causing the competitors that no longer match the input to be "kicked out" or to decrease in activation.[5][7] The processes by which words are activated and competitors rejected in the cohort model are frequently called "activation and selection" or "recognition and competition." These processes continue until an instant, called the recognition point,[5] at which only one word remains activated and all competitors have been kicked out.



Anonymous caresse said...

what about the new psychlopedia?

4:09 PM  

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