| Abstract: | Reports results of 5 experiments with a total of 168 male albino Sprague-Dawley rats. Presentation of an aversive CS produced an acceleration of free-operant Sidman shock-avoidance responding only if the CS had been paried with a relatively weak-shock UCS. Stimuli paired with a relatively strong UCS produced suppression of avoidance responding. With appropriate shock intensities, both suppression and acceleration were obtained. Responses of controls showed that this effect was not due to interactions between the operant response and UCS. In a within-S experiment, the same aversive CS produced suppression of an appetitive response (CER) and acceleration of avoidance. However, a CS which had produced avoidance acceleration did not suppress an appetitive operant. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
