Does colour provide an input to human motion perception?

Abstract

A PUZZLING feature of the visual system of primates is the occurrence of a multiplicity of separate ‘maps’ of the visual environment, each of which has its own independent set of afferent connections. Perhaps these maps represent an early stae in the analysis of visual information by the brain. Electrophysiological studies have shown that depth is analysed in V₂ (area 18)(ref. 1), that colour-coded cells occur mainly in V₄ and that motion in the visual field is analysed in the posterior bank of the superior temporal sulcus² (Fig. 1). We report here an experiment which suggests that colour and movement are handled separately in the visual system and that information defined by wavelength cannot be processed by the brain's motion-detecting mechanisms. This finding is consistent with Zeki's demonstration that “cells of the movement area are not concerned with colour”^2,3.