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Abstract:
Abstract: A fundamental question in memory is how the brain
codes for vivid sensory aspects of a remembrance, such as the
appearance of a recently encountered face or the tune from a
favorite song. Studies of mental imagery suggest that activity in
visual cortical areas increases during the active reconstruction of
visual images. Similar processes may be at work during the
retrieval of vivid memories in both the visual and auditory
domains. Employing event-related functional magnetic resonance
imaging procedures in 24 subjects we show that brain regions in
visual and auditory cortex are transiently active during
recollections that involve visual and auditory content,
respectively. We used a paradigm in which subjects learned and were
subsequently scanned and tested for perception and recall on a set
of 20 visual and 20 auditory items that were paired with
descriptive labels. For example, the label DOG was paired with a
picture of a dog for half of the subjects, and was paired with the
sound of a dog barking for the other half. Results show regions of
activation in extrastriate visual cortex during visual recall and
secondary auditory cortex during auditory recall. These regions are
subsets of regions activated during perception, indicating that
retrieval of sensory-specific memories involves a reactivation of
cortex involved in the processing of that sensory
information.
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