[Effect of high spatial frequencies on processes of visual recognition]

Optical filtration of the spatial-frequency range high-frequency component of numerical images affected the probability of their recognition and amplitude--temporal features of the visual EPs in occipital leads O1 and O2. Blurring of the images entailed a decrease of the recognition probability as well as of the late phases amplitudes of the EPs (N1 and P2). When the extreme spatial frequency of the image increases, the spike latencies of the N1 increase as well whereas those of the P2 decrease. The N1 wave seems to reflect activation of selectively set narrow--band spatial--frequency filters of the visual sensory system, while P2 wave reflects processes of decision-making in recognition and depends on the amount of images features subjected to analysis.