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Abstract:
A crucial first step in the use of functional MRI techniques
for testing memory enhancing pharmacologic agents, is the
development of simple, reliable stimulus paradigms. We have
previously reported a fMRI study during the encoding of novel
face-name associations, showing robust prefrontal, anterior
hippocampal and fusiform activation in healthy young adults. In
order to develop several sets of novel face-name stimuli that could
be used for assessing fMRI activation on multiple occasions, we
studied 20 healthy volunteers, age 22 - 51. Each subject was tested
on 5 occasions at least 24 hours apart, with a randomized order of
stimulus sets. Each stimulus set consisted of 84 novel face-name
pairs and 2 repeated face-name pairs, and were matched across sets
for age, gender, ethnic group composition. Two memory tests were
administered after each encoding session: a facial recognition test
with subsequent free recall of the name associated with the face
and then a forced choice face-name recognition task. There were no
significant differences across the 5 stimulus sets in percent
correct for face recognition (86.9 +/- 2.4%), free recall of the
name (35.7 +/- 1.9%) and forced choice face-name association (85.5
+/- 1.8%). FMRI studies using these stimulus sets to assess
test-retest reliability in the pattern of activation, and the
effects of two pharmacologic agents known to impair memory
(lorazepam and scopolamine) are currently underway.
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