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Abstract:
Abstract: Many have suggested that mental imagery and visual
perception are mediated by similar neural and cognitive mechanisms
(e.g. Goldenberg, et al., 1989; Kosslyn, et al, 1991; Levine, et
al., 1985). We investigated perceptual and imagery processing
during fMRI scanning. Subjects viewed a complex photographic scene
and were told to remember it. In the Mental Imagery condition, they
viewed the photograph for 2 seconds, followed by a 4 second delay
during which they were to maintain a mental image of the stimulus.
In the Visual Perception condition, subjects viewed the stimuli for
6 seconds. Following presentation of the stimuli in the Visual
Perception condition, and after the delay in the case of the Mental
Imagery condition, subjects made a yes/no response to a picture
fragment. In results from preliminary analyses we observe similar
common areas of activation in V1 and V2 (Brodmann's areas [BA] 17
& 18). Furthermore, compared with the visual condition, the
imaginal condition occurs in higher-level visual areas (BA 19) and
inferior temporal regions (BA 39). Comparisons of young (ages
18-30) and elderly (65-75) will be discussed. Supported by NIA
(RO1-AG06265).
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