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Abstract:
Abstract: Using Positron Emission Tomography (PET) with 12
healthy subjects, we compared within-modality and cross-modality
visual and haptic memory for abstract three dimensional objects. In
a 2x2x2 design, subjects examined the stimulus objects either
haptically or visually, and then took a yes/no recognition test,
either in the same or the other sensory modality. Recognition
performance was similar for both visual and haptic recognition. At
the neural level, a multivariate analysis (Partial Least Squares)
of the PET data identified two significant patterns of activity
(permutation test p<.001), one related to the modality of
processing (visual vs.haptic) and the other to the memory task
(encoding vs.recognition). Visual processing activated posterior
occipito-temporal regions, whereas haptic processing activated SI
and SII bilaterally, lateral and medial premotor regions
bilaterally, and cerebellum. During encoding of both visual and
haptic information, greater activity was observed in superior
prefrontal cortex bilaterally, right medial temporal lobe and
posterior inferior temporal gyrus bilaterally. During recognition,
greater activity was observed in a right frontal polar region,
frontal operculum bilaterally, and in a medial superior frontal
region. The results provide an initial characterization of
similarities and differences in neural correlates of comparative
visual and haptic memory.
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