Reversal set formation in the visually decorticate rat.

Rats given large visual cortex lesions demonstrated a simultaneous task reversal deficit previously reported to follow more extensive cortical ablation. However, no deficit appeared in an operant discrimination that deemphasized visuospatial cues, and the simultaneous task deficit vanished when translucent eye occluders were applied to eliminate spatial, but not intensity, cue use. Because the lesion subjects showed an impairment only when visuospatial cues were available and relevant to correct reversal performance, they seemed hindered by their incompetent processing of visuospatial information. The results are interpreted as support for spatial rather than learning approaches to visual cortex function.