CORTICAL LESIONS AND RESPONSE INHIBITION IN CATS

Groups of five cats each, with lesions in gyrus proreus, in the pericruciate area, and in both areas, were tested on 6 tasks yielding measures of perseveration and of deficiencies in response suppression. The animals with pericruciate lesions were inferior to normal controls only in the rate with which they extinguished responding in a runway. No evidence that pericruciate lesions exacerbate the effects of proreal lesions was obtained. Cats with proreus or combined lesions and severe retrograde degeneration in the mediodorsal nucleus showed marked impairments on all tasks studied. Subjects with proreal or combined lesions and less severe degeneration in MD showed similar but midler and more transient impairments on extinction and reversal tasks. Intercorrelations between seven measures of learning performance did not suggest that the behavioral impairments in the brain-injured cats could be explained in terms of the disruption of one or two pervasive forms of inhibition. An impairment in reversal learning in cats with of one or two pervasive forms of onhibition. An impairment in reversal learning in cats with lesions in the posterior association cortex involving Ep was also described. © 1969.