Motion detection by biological asymmetrical neural network

The author discusses a problem of motion perception in the neural network of the catfish retina. Linear and nonlinear information are crucial to visual processing in the catfish retinal network. Horizontal and bipolar cell responses are linearly related to the input modulation of light, while amacrine cells work as a nonlinear function of squaring. These cells make an asymmetrical nonlinear network. The author solves a problem of motion perception in the catfish retinal-like network. It is shown that this asymmetrical neural network is sensitive to the directional moving stimulus. The conditions of the directional movement are shown by the equations of Wiener kernels in the asymmetrical neural network. It is also shown that a symmetrical neural network cannot determine the equations for the moving stimulus