Reversal set formation in the visually decorticate rat.

Results of 4 experiments with 32 male black-hooded rats show that Ss given large visual cortex lesions demonstrated a simultaneous task reversal deficit previously reported by R. C. Gonzales et al (1964) 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 Ss 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. Results support spatial rather than learning approaches to visual cortex function. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)