Traumatic avoidance learning: the effects of CS-US interval with a delayed-conditioning procedure.

Abstract

By means of a delayed conditioning procedure in a shock-avoidance apparatus with dogs, the CS-US interval was varied from 5 to 80 seconds; acquisition and extinction measures were compared to those secured in a similar experiment (Kamin, J. c. p. P, 1954, 47, 65-72) in which the trace-conditioning procedure was used. The delayed conditioning procedure produces faster acquisition, as measured by shocks to first avoidance response or trials to an avoidance criterion, and the avoidance habit shows much greater resistance to extinction. The superiority of delayed-conditioning increases as the CS-US interval is increased. "The quantitative features of our findings suggest that, in traumatic avoidance learning, the initial development of conditioned anxiety depends heavily on the time interval between CS onset and US onset, while the strengthening of the learned avoidance response depends heavily on the conditions of the CS termination.".