A new theory of direction-selective visual motion discrimination

The visual cortex is known to contain neurons that respond selectively to the direction of visual motion. The responses of those neurons are said to be 'non-separable' because they cannot be constructed from separate spatial and temporal processes. How neurons compute those responses without resort to explicit time delays is unknown.

We propose a novel neural mechanism which relies on the predisposition of cortical tissue to generate travelling waves. We show that those endogenously generated waves can resonate with the space-time signature of the visual stimulus to selectively respond to visual motion. The speed and direction of the waves are governed by the profile of the lateral-inhibitory coupling. Hence time delays are not required. 

 

Heitmann & Ermentrout (2020) Direction-Selective Motion Discrimination by Traveling Waves in Visual Cortex. PLoS Computational Biology 16(9): e1008164.

Heitmann & Ermentrout (2016) Propagating Waves as a Cortical Mechanism of Direction-Selectivity in V1 Motion Cells. Proc 9th EAI Intl Conf on Bio-inspired Info & Comm Tech. BICT'15. New York.