A theory of direction selectivity for macaque primary visual cortex

Motion perception is important for primates, and direction selectivity (DS), the ability to perceive the direction a target is moving, is an essential part of motion perception. Yet no satisfactory mechanistic explanation has been proposed for the origin of DS in the primate visual cortex up until now. In this paper, we hypothesize that DS is initiated in feed-forward LGN input as a result of the dynamic differences between the ON and OFF pathways. The mechanisms we propose are biology based, and our theory explains experimental data for all spatial and temporal frequencies in visual stimuli. Exploiting temporal biases in parallel pathways is relevant beyond visual neuroscience; similar ideas likely apply to other types of neural signal processing.