Visual discrimination in cats: physical parameters of stimuli and effects of visual cortex ablation

Correct reaction probability and minimum exposition time in visual form discrimination task were studied under the conditions of varying pattern parameters. The minimal exposition time depended on pattern contrast and pattern background ratio and on the number of screen position variations. However, it remained unchanged when the background luminance and pattern size varied within the suprathreshold range. The deficits of discrimination in the minimal exposition time conditions in animals with damages to the striate and parastriate cortical regions suggest that the visual cortex participates in the analysis of shortterm stimuli and is responsible for prolongation of the visual trace within the time necessary for object discrimination.