A MODEL OF NEURONAL RESPONSES IN VISUAL AREA MT

Electrophysiological studies indicate that neurons in the middle tempo ral (MT) area of the primate brain are selective for the velocity of v isual stimuli, This paper describes a computational model of MT physio logy, in which local image velocities are represented via the distribu tion of MT neuronal responses, The computation is performed in two sta ges, corresponding to neurons in cortical areas V1 and MT, Each stage computes a weighted linear sum of inputs, followed by rectification an d divisive normalization. V1 receptive held weights are designed for o rientation and direction selectivity. MT receptive field weights are d esigned for velocity (both speed and direction) selectivity. The paper includes computational simulations accounting for a wide range of phy siological data, and describes experiments that could be used to furth er test and refine the model, (C) 1998 Elsevier Science Ltd, All right s reserved.