Some unusual properties of neurones in the cat posterotemporal cortex.

Visual receptive fields (RF) of 103 single units in posterotemporal cortex (area 21) were investigated in cats immobilized by d-tubocurarine. The method of express-mapping of the RF allows to estimate every 3.3 min its localization, size and configuration. A considerable variability of RF size and form was revealed in 35% of units. In 88% of the unit studied the RFs were invariant with adaptation level. Little dependence of the response on the length of the light bar, but a definite orientational sensitivity was found. Spontaneous displacements of the RF in the visual field are found in 14% of the visually activated cells. Such RF dislocations varied in magnitude from 3.5 upto 25 degrees and were mainly horizontal. The mechanisms of RF variability and displacement in the visual field are discussed in connection with possible influence of the copy of the motor command that introduces corrections in the visual coordinates in area 21 to provide for the constancy of vision.