MAP - A MACINTOSH PROGRAM FOR GENERATING CATEGORICAL MAPS APPLIED TO CORTICAL MAPPING

One technique for studying the cortex entails mapping the distribution of neuronal response properties across a cortical lone. In sensory co rtex, 'receptive fields' are arranged in an orderly way such that they form a topographical representation, or 'map', of the sensory surface on the cortex. Detailed maps can be constructed by making many microe lectrode penetrations across the cortex and measuring the receptive fi eld at each site. A computer program called MAP was designed to aid in the efficient generation of these maps. MAP allows the user to mark p enetration sites on digitized images of the cortical surface and to dr aw receptive fields on digitized images of the skin surface being stud ied. Penetration sites are then automatically assigned a category base d on the location of the receptive field. MAP has significantly increa sed the speed of this experimental process. MAP contains a number of m echanisms designed to facilitate analysis. For example, it can automat ically generate cortical maps based on receptive field locations. It c an also show recorded neurophysiological data at each penetration site allowing the experimenter to visualize activity across the cortical z one. These features along with several others make MAP an effective to ol for cortical mapping.