The goal of the proposed experiments is to determine how many distinct visual areas exist in macaque intraparietal sulcus and annectent gyrus, and to discover how these areas are organized, topographically, connectionally and hierarchically. We hypothesize that there may be as many as four distinct areas within the intraparietal sulcus. A second hypothesis is that these areas are topographically organized, containing a systematic representation of the visual field. The third hypothesis is that the connections of these areas are topographically organized. Finally, we also intend to determine the position of each area in the hierarchy of cortical visual areas and determine whether each area belongs to one or another of the specific channels identified within the overall hierarchy. Anatomical methods will be used to outline the borders and overall topography of each area. Physiological mapping of receptive field position will be done to produce a finer-grained analysis of the visuotopic organization in each area. Finally, the connections of each area will be determined and their topographic and hierarchical organization will be analyzed. The purpose of these experiments is to provide the basis for a more precise description of the flow of information through extrastriate visual cortex. Such a description is essential to a complete understanding of the physiological mechanisms of visual perception and visually guided behavior in these higher-order areas. Ultimately, this information will be of use in the treatment of perceptual deficits after cortical damage and in the development of visual protheses.
Colby, C L; Gattass, R; Olson, C R et al. (1988) Topographical organization of cortical afferents to extrastriate visual area PO in the macaque: a dual tracer study. J Comp Neurol 269:392-413 |