[Detector neurons of the visual cortex of the chipmunk]

Three functional classes of neurons are described in the Siberian chipmunk visual cortex: neurons nonselective to movement direction, movement-direction-selective neurons and orientation-selective neurons. Nonselective and direction-selective neurons showed maximum adaptiveness at high speeds of movement: 100-500 degrees/s and more. Most of orientation-selective neurons were maximally activated at speeds 10-50 degrees/s. For all neuronal classes a clear-cut correlation between selectivity and movement speed as well as pattern of responses to stationary stimuli in the receptive field were found. The data obtained allowed a division of the neurons into two groups: phasically-fast and tonically-slow with predominance of the first group.