Delayed Avoidance Conditioning: Warning Stimulus (CS) Duration

Abstract

A first step in the study of this problem was an examination of temporal parameters. In this study, CS durations longer than 5 sec. were employed in order to explore the possibility that prolongation of the CS might facilitate acquisition in the Skinnex box. Although previous results obtained with the shuttle-box suggested that short CS durations are more favorable for avoidance acquisition (Solomon & Brush, 1956; Woodward, 1954), performance in the Skinner and shuttle-box is sufficiently cl~ss~m~lar to merit questioning the generality of the results obtained with the latrer. Moreover, Meyer, el al. (1960) reported that the use of a CS of less than 5 sec. failed to facilitate acquisition in the Skinner box. This finding suggested that, if CS duration has any relevance to acquisition, the effects must be related to a range of durations of longer than 5 sec. Two experiments are reported. In Exp. 1, rats were trained with varied CS durations. During testing the CS was constant for all animals in order to assess differences resulting from the previous training without biasing latency requirements of the avoidance response. In Exp. 2, the longest CS duration was decreased gradually in order to mitigate the disruptive effects of an abrupt change in latency requirements.