Choosing Between Predictable Shock Schedules: Long- Versus Short-Duration Signals
Journal of the Experimental Analysis of Behavior
Two experiments assessed the relative aversiveness of different duration preshock (PS) signals (5 and 20 sec) and different duration stimuli identifying shock-free periods. In Exp I, the responding of 15 of 18 female Sprague-Dawley rats was maintained when it produced changes from a predictable-shock condition with a 5-sec PS signal to an identical schedule with a 20-sec PS signal; responding was not maintained when it produced the opposite changes. These results occurred with intershock intervals of both 120 and 240 sec. Exp II assessed whether changing to the 20-sec schedule was maintained by properties of the PS signals identifying the shock periods or by properties of the stimuli identifying the shock-free periods. Four similar rats were given training with the 2 signaled schedules in an operant chamber and then later given off-baseline preference tests in a shuttlebox. When given a choice between PS signals, Ss chose the 5-sec over the 20-sec signals. However, when given a choice between stimuli identifying shock-free periods, Ss chose the stimulus identifying the shorter shock-free periods (i.e., the one previously correlated with the 20-sec signals). Findings are discussed within the R. A. Rescorla and A. R. Wagner (1972) model of stimulus compounds and within the context of safety as a contrast phenomenon.
aversiveness of long & short duration preshock signals & varied interstimulus intervals, signal preferences & choice behavior, rats
Pietro Badia, Bruce B. Abbott, and L Schoen (1985).
Choosing Between Predictable Shock Schedules: Long- Versus Short-Duration Signals. Journal of the Experimental Analysis of Behavior.41 (3), 319-327.