From: LCINKO@ARIZVMS.BITNET
Newsgroups: bit.listserv.slart-l
Subject: Re: mental lexicon
Date: 15 Nov 92 21:29:11 GMT
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU
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While considering issues of mental lexicon, the discourse level certainly has
its relevance, but psycholoinguists try to isolate lexical issues, excluding
on purpose the discourse level so that variables can be clearly defined.  Now
words on which a lexical study focuses can be semantically primed.  For
instance, studies have been conducted regarding the lexical decision time for a
target word such as 'nurse'.  Lexical dicision time for a word like 'nurse' is,
indeed, faster when preceded by a semantically related word such as 'doctor',
compared with a control condition in which 'nurse' is preceded by an unrelated
word such as 'table'.

In a lexical decision task, words are given as stimuli, and subjects press a
button for words and another for non words, and the experimenter records how
long it takes to make each decision.  I suspect one could design a similar
study for a second language.  The question is, however, when learning a second
language, especially learning it in an instructional environment, do we store
vocabulary immediately in a linguistic or episodic memory, or is it primarily
considered as a factual information like any other type of information learned
in a math class?  For those interested in lexical acquisition it would be a
great research question.

Other studies have been designed recording electric activities of the brain in
response to a word stimulus, so called event-relatede potentials (ERPs).  ERPs
are recordings of brain neuroelectric activities in response to the occurence
of a discrete event, and their analyses are directed towrad an understanding of
underlying brain specializations and the neural activities that govern
cognitive processes.   While language has been found to be primarily located in
the left hemisphere (especially in the Broca's and Wernicke's areas) both
hemispheres are connected by the corpus collosum, a massive bundle of nerves
which constantly send signals righ and left, left and right, in search of the
best approach to a particular task.  The use of ERPs determined that the two
hemispheres are not working in isolation.  As a matter of fact, the left and
right hemispheres seem to have complementary language functions.  For instance,
Kutas and Hillyard (1983) found that there is a greater left hemisphere
positivity in the ERP to open-class (content) words, and a greater right
hemisphere positivity in ERPs to closed-class (function) words.  ERP studies in
sentence processing also suggest that there is a strong influence of context on
word recognition. ERP studies also indicate that there is a division between
form-based constraints and content/meaning based contraints on sentence
structure and that the brain can tap into different modes of cognitive
reactions to deviations, whether semantic, grammatical or physical.

WEll, I'm gonna stop here... otherwise I'll write a dissertation!!!

Lydie Meunier-Cinko

lcinko@ccit.arizona.edu   /    lcinko@arizvms
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU