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Word Comprehension
The primary goal of the research in this area include study of language
comprehension from a cognitive neuroscience perspective. Many of the
studies ongoing in the lab are focused on providing answers to questions
about the sequence and timing of neural events that underlie the
perceptual and cognitive processes involved in visual word
comprehension. This research has three specific aims. The first is to
test and elaborate on predictions of the Bi-modal Interactive Activation
Model (BIAM) of word comprehension in competent adult users of language.
While models like the BIAM have been touted as neurally plausible,
relatively little work using cognitive neuroscience methods has actually
attempted to test the predictions of such models. A second complementary
aim focuses on improving the precision of
ERP measures
of word processing by providing a better understanding of their
relationship with the perceptual, cognitive and linguistic processes
they are hypothesized to reflect. A third aim seeks to improve our
understanding of word comprehension by examining how comprehension
processes develop over time. In one group of studies we are using masked
priming in normal young adults. This paradigm has allowed us to isolate
four temporally overlapping ERP effects that we have hypothesized are
sensitive to a cascade of word comprehension processes. We are currently
testing predictions about the processing nature and timing of these ERP
effects and plan to use these ERP effects to test predictions generated
by the BIAM. A second group of ongoing studies include single word
experiments, also in young adults, where a number of variables are
manipulated that have previously been suggested to influence early
visual word comprehension processes. We have hypothesize that previous
failures to see effects with these variables were due to lack of power.
A final group of studies will include word comprehension experiments
modeled on the young adult studies mentioned above. These will be run in
five groups of children between 7 and 11 years of age. The point of
these experiments is to allow us to examine the development of visual
word comprehension over time and thus better characterize changes in
some of the neural/cognitive processes involved in reading. One long
term goal is to extend these studies to children and adults with word
processing and other language/cognitive deficits.
Reading and Sign Processing in the Deaf
In a second major line of research we are collaborating with Dr. Karen
Emmorey and the Language and Cognitive Neuroscience Laboratory at SDSU.
Projects in this area are primarily focused on issues of word and sign
processing in congenitally deaf individuals who use American Sign Language
(ASL) as their first (L1) language. We are particularly interested in providing
a better understanding of the temporal dynamics of visual word recognition
in deaf readers. Most deaf readers struggle to acquire the fundamentals
necessary to be skilled readers of spoken languages. Shedding light on the
neurocognitive mechanisms that support visual word recognition and
reading in this population is one important goal of our research. We are also
studying the neurocognitive mechanisms that underlie processing of ASL
signs as well as interactivity of sign and word processing in deaf bi-modal
bilinguals. Many of the issues of interest here are similar to ones discussed
below in our projects on bilingualism. Be sure to visit the
Laboratory for
Language and Cognitive Neuroscience website.
Bilingualism and Second Language Learning
In
most of the world, bilingualism is the norm. Even in the US, a
primarily monolingual society, there is a growing awareness that
knowledge of a second language is essential to our competitiveness in an
increasingly interactive world. However, there are a number of issues
concerning the cognitive and neural systems that underlie monolingual
and bilingual language use that remain unresolved. This research
focuses on one specific but critical component of the mechanisms
involved in being bilingual-the cognitive and neural processes involved
in acquiring and using a vocabulary in a second language (L2). Using
both behavioral and electrophysiological (ERP) techniques, our aim is to
plot the cognitive and neural consequences of vocabulary acquisition in
a foreign language by examining various stages of L2 language learning
in both cross-sectional and longitudinal samples. Behavioral data
allows this research to be linked with the large amount of prior
behavioral research on these and similar issues; ERP data will allow
both quantitative and qualitative changes in the processing of L2 words
to be tracked as a function of proficiency with the high degree of
temporal accuracy associated with ERPs.
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