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Abstract:
Though memory impairment in persons with schizophrenia has
been reported, great diversity in memory performance exists in this
population. This study attempts to identify patterns of memory
deficit in persons with schizophrenia and relate them to
differences in brain metabolism during a verbal working memory
task. Through cognitive testing, we identified a group of persons
with schizophrenia or schizoaffective disorder with specific verbal
memory deficit (SVD group) and another group whose performance is
unimpaired (Good Memory; GM group). We used fMRI to compare these
groups brain activations to normal controls during a serial
position task with two levels of difficulty that used familiar
sounds to activate verbal memoranda. Memoranda number was adjusted
to match performance across subjects. Preliminary results indicated
similar performance across groups. The easy and hard versions of
the task consistently activated the same brain regions but to a
somewhat greater extent in the hard version. Auditory cortex
excitations during stimulus encoding were similar in all groups.
During retention, controls and GM patients activated the inferior
frontal (IF) cortex. The SVD patients activated this area less and
appeared to engage the middle frontal (MF) gyrus. Findings suggest
that the GM and control groups used similar frontal structures in
completing a verbal memory serial position task. SVD may have been
unable to fully activate the IF and may have used the MF to
accomplish task-related mnemonic functions.
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