EFFECT OF CAUDATE AND SEPTAL NUCLEI LESIONS ON RESISTANCE TO EXTINCTION AND DELAYED-ALTERNATION

FOLLOWING 15 DAILY CONDITIONING-EXTINCTION SESSIONS AND TRAINING ON SPATIAL DELAYED-ALTERNATION (DA), 3 RHESUS MONKEYS RECEIVED SEPTAL NUCLEI LESIONS, 3 RECEIVED HEAD OF CAUDATE NUCLEUS LESIONS, AND 3 REMAINED UNOPERATED CONTROLS. ALL SS WERE TESTED FOR ANOTHER 5 CONDITIONING-EXTINCTION SESSIONS AND FOR RETENTION OF DA. BOTH SEPTAL AND CAUDATE LESIONS RESULTED IN INCREASED RESISTANCE TO EXTINCTION; SEPTAL LESIONS WERE ALSO FOLLOWED BY INCREASED CONDITIONING RATES. ON RETENTION OF DA, CAUDATES, IN COMPARISON TO CONTROLS AND SEPTALS, WERE IMPAIRED. THE ORBITAL FRONTAL CORTEX, THE SEPTAL NUCLEI, AND THE VENTROLATERAL SECTOR OF THE CAUDATE APPEAR TO BE PART OF A NEURAL SYSTEM CONCERNED WITH REGULATING RESPONSE TENDENCIES. (16 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1968 American Psychological Association.