Delayed alternation learning under electrical (blocking) stimulation of the caudate nucleus in the cat

Of 9 cats with electrodes implanted in the dorsolateral caudate nucleus, 4 had previously reached criterion on a delayed alternation task. Tested under alternating conditions of stimulation and nonstimulation, these 4 animals showed a significant performance decline with stimulation. When a marker was placed on one response panel, performance under stimulation did not decline. Stimulation did not affect the learning of a visual discrimination. The remaining 5 cats were trained on delayed alternation with alternating stimulation and nonstimulation conditions. Under stimulation, performance remained near chance levels. These animals were tested on position learning and reversal, and under unilateral stimulation. The results support the view that the caudate nucleus and prefrontal cortex mediate separate aspects of delayed response behavior.