Differential second-order aversive conditioning using contextual stimuli

Abstract

Two experiments were conducted to determine if contextual stimuli used as S 2 in a higher-order differential conditioning procedure would control the performance of rats. Discrete stimuli were first paired with footshock in a separate training context. During second-order training, a shock-associated discrete stimulus was presented in one of two discriminable observation chambers. Over 4 days of training, subjects engaged in more freezing in the context associated with an excitatory discrete S 1, relative to a context in which no discrete stimulus, or a stimulus that had been explicitly unpaired with shock delivery, was presented. After acquisition of the second-order discrimination, animals were returned to the original training context where they received a "signaled inflation" treatment designed to change the current value of S 1, and the US. This postconditioning manipulation did not selectively affect performance of defensive freezing or conditional analgesia in S 2. © 1989 Psychonomic Society, Inc.