Visual latencies in cytochrome oxidase bands of macaque area V2.

Cytochrome oxidase bands in area V2 of the primate visual cortex constitute separate relays for parallel channels relaying information from area V1 to other extrastriate cortical areas. We investigated whether information is transferred at the same speed in the different channels by measuring the latencies of neurons in different cytochrome oxidase bands identified by the presence or absence of retrogradely labeled cells from injections in area V4. Results show that neurons in the thick and pale bands respond 20 msec earlier than those in the thin bands. We also found that color-selective neurons respond later than neurons with no selectivity for color and that direction-selective neurons have shorter latencies than neurons with no selectivity for the direction of stimulus movement.