Spatial and temporal structure of receptive fields in primate somatosensory area 3b: effects of stimulus scanning direction and orientation

TitleSpatial and temporal structure of receptive fields in primate somatosensory area 3b: effects of stimulus scanning direction and orientation
Publication TypeJournal Article
Year of Publication2000
AuthorsDiCarlo JJ, Johnson KO
JournalThe Journal of Neuroscience: The Official Journal of the Society for Neuroscience
Volume20
Pagination495–510
Date Publishedjan
ISSN1529-2401
KeywordsAction Potentials, Animals, Discrimination Learning, Fingers, Macaca mulatta, Movement, Normal Distribution, Reaction Time, Somatosensory Cortex, Space Perception, Time Factors, Touch
Abstract

This is the third in a series of studies of the neural representation of tactile spatial form in somatosensory cortical area 3b of the alert monkey. We previously studied the spatial structure of {\textgreater}350 fingerpad receptive fields {(RFs)} with random-dot patterns scanned in one direction () and at varying velocities (). Those studies showed that area 3b {RFs} have a wide range of spatial structures that are virtually unaffected by changes in scanning velocity. In this study, 62 area 3b neurons were studied with three to eight scanning directions (58 with four or more directions). The data from all three studies are described accurately by an {RF} model with three components: (1) a single, central excitatory region of short duration, (2) one or more inhibitory regions, also of short duration, that are adjacent to and nearly synchronous with the excitation, and (3) a region of inhibition that overlaps the excitation partially or totally and is temporally delayed with respect to the first two components. The mean correlation between the observed {RFs} and the {RFs} predicted by this three-component model was 0.81. The three-component {RFs} also predicted orientation sensitivity and preferred orientation to a scanned bar accurately. The orientation sensitivity was determined most strongly by the intensity of the coincident {RF} inhibition in relation to the excitation. Both orientation sensitivity and this ratio were stronger in the supragranular and infragranular layers than in layer {IV.}

URLhttp://dicarlolab.mit.edu/sites/dicarlolab.mit.edu/files/pubs/JNdirection.pdf
Refereed DesignationRefereed

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