The relationship between Negative Contrast, Positive Contrast, and the Frustration Effect in a modified double-alley runway

Abstract

Recent evidence indicates that the Positive Contrast Effect (PCE) is dependent upon a temporal interval that is maximal for the Frustration Effect (FE). These data suggest that PCE and FE may be indicative of the energizing function of frustrative nonrevard or nonzero reward reductions, while the Negative Contrast Effect (NCE) may be indicative of the inhibitory function of frustration (e.g., Amsel, 1958, 1962). If this is true, then a) it should be possible to provide a within-S demonstration of NCE, PCE, and FE, and b) factors that influence the development of FE should influence the de velopment of PCE. Bats (N = 60) were divided into 5 groups (20-0, 20-4, 20, and 0) and given 192 discrimination trials in a modified double-alley runway. S-trials were either longsignalled or short-signalled, ss were given 4 trials per day; the intertriai interval (XTI) between Trials 1 and 2 and between Trials 3 and 4 was 20 seconds, while the ITis between Trials 2 and 3 and between Trials 4 and 1 were 20 minutes and 24 hours, respectively. In Phase 1, start, run, and goal speeds in the alley were recorded; postreward activity over three consecutive 5-second intervals was recorded. In Phase 2 (the last 48 trials), hurdle-jumping replaced activity. The data showed NCE, PCE, and FE in the same S; NCE and PCE occurred in the start measure, while FE occurred in both vii the activity measures and the hurdle-jump measure. Although PCE did occur under conditions maximal for FE (i.e., in the start data on S+ trials after S-trials at short ITI), PCE did not vary as a function of reward magnitude. It was sug gested that differences in the tasks used to measure FE and PCE may have obscured magnitude effects, otherwise, the results of the study were interpreted as consistent with Amsel's (1958, 1962) Frustration hypothesis.