Abstract: | The position of on- and off-discharge centers in class 1 and 3 receptive fields of the frog retina was determined with the aid of moving bars of different lengths. On- and off-centers of receptive fields of the first group coincide, those of the second are spatially separate, and in fields of the 3rd group the discharge center of one contrast sign occupies the central position and discharge centers of the opposite sign are located at the periphery, to its right and left. Receptive fields of the frog retina thus have features which approximate them to the concentric receptive fields of geniculate neurons and the fields of the cat visual cortex. Asymmetry in the responses was found: during movement in opposite directions the distance between the discharge centers changed, during movement to one side only one of the peripheral centers was revealed, whereas during movement to the other side the second center was revealed on the opposite side of the receptive field. This asymmetry of spatiotemporal relations in the receptive fields is similar to that found in the fields of cortical neurons and is connected with their directional properties.Research Institute of Applied Mathematics and Cybernetics, N. I. Lobachevskii State University, Gor'kii. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 75–85, January–February, 1980. |