Occipitotemporal corticocortical connections in the rhesus monkey

Previous behavioral studies indicated that the inferior convexity of the temporal lobe in the rhesus monkey functions in relation to the visual system and that this function probably depends on corticocortical connections which link this area to the visual areas. Therefore, in an experimental anatomical study the corticocortical connections of some of the occipital, temporal and frontal areas were investigated in the monkey, by means of the Nauta-Gygax silver impregnation technique. The following findings were obtained. The striate cortex projects to certain parts of a “circumstriate cortical belt” which extends into the caudal bank of the superior temporal sulcus in its upper parts and into the caudal parts of the intraparietal sulcus. This circumstriate belt in turn projects to the inferior convexity of the temporal lobe and to the cortex around the arcuate sulcus of the frontal lobe. The inferior convexity of the temporal lobe in turn projects back to parts of the circumstriate belt and to the lateral and the ventrolateral surface of the frontal lobe.