Some cortical projections of the dorsomedial visual area (DM) of association cortex in the owl monkey, Aotus trivirgatus

Abstract

Efferent projections from the dorsomedial visual area (DM) in the owl monkey to other portions of visually responsive cortex were determined by degeneration and autoradiograhic methods of demonstrating axon pathways. The most prominent ipsilateral pathway was to posterior parietal cortex (PP) just medial to the terminal portion of the Sylvian fissure. Other ipsilateral projections were to subdivisions of the temporal lobe, the middle temporal visual area (MT) and the surrounding dorsolateral crescent (DL), to regions just rostral to area 18 on the medial wall of the cerebral hemisphere, and to the upper bank of the Sylvian fissure. The callosal projections of DM were to DM, PP, and MT of the opposite cerebral hemisphere. The results support the notion that visual association cortex consists of a number of separate, but complexly interrelated, subdivisions. The efferents to posterior parietal cortex suggest the possibility of an area for the integration of somatosensory and visual information.