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Abstract:
Abstract: Functional Magnetic Resonance Imaging (fMRI) was
used to investigate the time course and amplitude of brain activity
in language related (e.g., left inferior frontal and left temporal)
areas during the processing of sentences which contained either
lexically ambiguous words or matched unambiguous control words.
Using an Event-Related fMRI paradigm, brain activity was measured
every 1500 milliseconds during the processing of individual
sentences which were presented one word at a time at a variable
rate. The acquisition of the superior most slice was synchronized
with the presentation of the ambiguous word within the sentences.
Higher levels of activation occurred during the reading of
sentences which contained lexically ambiguous words than during the
reading of sentences which contained the matched unambiguous
control words. Furthermore, the time course of brain activation
varied depending upon (1) brain region; and (2) whether the
sentence contained either a "balanced" (i.e., both meanings equally
likely) or a "biased" (i.e., one meaning more likely than other
meanings) ambiguous word. The findings indicate that event-related
functional imaging can be used to measure cognitive workload
associated with lexical processing in general and ambiguity
resolution in particular.
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