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Abstract:
To the extent that linguistic stimuli are processed in an
automatic or obligatory manner, methodologies that rely on
subtraction would not be adequate to isolate different stages of
processing. An alternative to using subtraction in imaging is to
use priming to differentially effect certain stages of processing.
Repetition priming is reflected in a decreased reaction time to
make a judgement on a previously presented word. The repetition
priming of words or word stems also results in a relative decrease
in fMRI signal in most of the language activated brain regions.
Phonemic priming has been found during many tasks involving the
presentation of rhyming word pairs. When compared to non-rhyming
word pairs, we hypothesized that the auditory presentation of
rhyming word pairs would produce priming and a concurrent relative
decrease in fMRI signal in those regions involved in (at least) the
initial stages of phonemic processing. Blocks of spoken rhyming
versus non-rhyming word pairs were alternated with a rest
condition. A tone task with similar parameters was also used.
Preliminary data showed that activity was decreased in some regions
during rhyming versus non-rhyming conditions. Further studies are
needed to examine the effects of pre-lexical and lexical phonemic
priming in order to determine the stage(s) of processing that are
reflected in the fMRI priming effects.
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