[Responses of rabbit's visual cortex neurons to changes in intensity and orientation of visual stimuli].

Changes in the number of spikes in the early phasic discharge (50-90 ms from stimuli replacement) of neurons in the rabbit's primary visual cortex were studied under conditions of an instant change in a flashing-line pattern. We used three type of stimulation: lines with different orientations (0-90 degrees) but constant intensity; lines with constant orientation but different intensities; complex stimuli with different intensities and different orientations of lines. Factor analysis made it possible to reconstruct two-dimensional sensory spaces of orientations in 13 of 43 analyzed neurons (30%). In 5 of 30 analyzed neurons (16.6%), both two-dimensional spaces of orientations and two-dimensional spaces of intensities were revealed. Achromatic spaces were reconstructed during changes in the lines of varying intensities but constant orientation. In experiments with complex stimuli, the intensity of lines with orientations varying from 0 to 38.58 degree was 5 cd/m2. The intensity of lines with orientations varying from 51.44 to 90 degrees was 15 cd/m2. In the sensorial space, stimuli with different intensities were located on the plane formed by the first and second significant factors in opposite quadrants, whereas within each quadrant, the stimuli were arranged closely to their orientation from minimum to maximum. We suggest that this type of sensory space reflects the interaction between intensity and orientation attributes of visual stimuli with the factor of intensity prevailing over the factor of orientation. Only 7 (12%) neurons with such complex spaces were found.