Multiple processing streams in occipitotemporal visual cortex.

The earliest stages of cortical visual processing in areas V1 and V2 of the macaque monkey contain internal subdivisions ('blobs' and 'interblobs' in layer 4B in V1; thin, thick and interstripes in V2) that are selectively interconnected and contain neurons with distinctive visual response properties. Here we use anatomical pathway tracing to demonstrate that higher visual areas, V4 and the ventral posterior inferotemporal cortex, each contain anatomical subdivisions that have distinct input and output projections. These findings, in conjunction with others, suggest that modularity and multistream processing within individual cortical areas are widespread features of neocortical organization.