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Abstract:
Abstract: People sometimes confuse memories of imaginations
for memories of perceptions. We studied this phenomenon using
event-related potentials (ERPs). At study, subjects viewed 350
words and visualized each corresponding object. For half, a
photograph of the object was also displayed. Next, a surprise
cross-modal recognition test for the photographs was given using
spoken words. On average, subjects remembered 72% of the viewed
objects and misremembered 28% of the imagined objects. True
memories may have been subjectively similar to false memories but
accompanied by more vivid visual imagery. Results supported this
idea, as occipital ERPs associated with true memories for objects
were more positive than false memory ERPs. These ERPs were similar
in latency and topography to ERPs associated with visual imagery
during recollection in a prior study (Gonsalves & Paller,
Memory&Cognition, in press). The ERP effect was also observed
when number of trials and response times were matched between the
two conditions. In addition, study-phase ERPs were analyzed for
potentials predictive of later memory, and such effects were found
at occipital and at frontal scalp locations. In conclusion, ERPs
that have previously been associated with visual imagery
differentiated between true and false memories, even though the
behavioral response did not. Our paradigm is thus useful for
generating errors in reality monitoring while providing neural
indications of the cognitive events underlying these memory
illusions.
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