[Correlation of topographic and spatial-frequency characteristics of the lateral suprasylvian region and the striate cortex in the cat].

Modulation transfer functions and retinotopic organization of the two largest areas of visual projections in the cat cerebral cortex were determined and compared. Receptive fields of the neurons in the lateral suprasylvian area are large and their size rapidly increases with eccentricity. In spatial-frequency terms they are low-pass filters. Latent time of visual evoked potentials is shorter in the suprasylvian area than in the striate cortex. It means that low spatial frequencies are transferred more quickly in that area than high spatial frequencies in the striate cortex. Reciprocal connections of the two retinotopically organized areas may accomplish the correlation of high and low frequency descriptions occurring in them.