Fear of the warning signal during overtraining of avoidance

The present experiment assessed the Pavlovian properties of a tone used as a warning signal in discrete-trial avoidance training of rats by measuring its ability to block conditioning to a light when the tone-light compound signalled shock in a conditioned suppression procedure. The results, although based on a different measure of Pavlovian conditioning, confirmed those reported by Starr and Mineka (1977). After moderate levels of avoidance training, the tone blocked conditioning to the light; but after extended avoidance training it no longer did so, even though a yoked group exposed to the same Pavlovian relation between tone and shock showed no such decline.