Neural correlates of asymptotic avoidance and classical conditioned leg felxion.

Brain correlates of conditioned leg flexion behavior were studied in dogs bearing chronically implanted electrodes. Animals were trained to asymptote under either classical aversive or avoidance contingencies, and then were retrained under the other contingency; the order of training was balanced across subjects. The training groups were further subdivided into 3and .5-set CS-US intervals. These procedures produced stable behavior and large differences in response latency such that CS onset controlled latency under the avoidance contingency and CS duration controlled latency under the classical contingency. The discharge rate of multiple unit activity recorded from motor, association, and auditory cortices during asymptotic performance was characterized by primary and secondary peaks. Primary peak latencies were invariant with respect to flexion behavior. The latencies of secondary peaks varied as a function of the behavioral response latency and generally preceded the onset of flexion behavior.