Positive contrast effects as a function of method of incentive presentation.

Abstract

Incentive contrast phenomena were investigated by varying method of incentive presentation. The typical within-6 1 design was modified to permit SB the choice of the incentive magnitude on every trial. This procedure resulted in a positive contrast effect. Analyses of the first-order conditional response probabilities provided support for traditional reinforcement interpretations of choice behavior in opposition to the results of other similar studies.

Shifts in magnitude of reward with humans in the “straightaway”

“…In terms of the frequency with which the stimulus events are guessed, a NCE but no PCE; neither a NCE nor a PCE; and both a PCE and a NCE have all been reported (cf. Chapman and Halpern, 1969;Halpern, Schwartz, & Chapman, 1968 The present experiments sought to clarify an.j to extend the research on contrast effects with hLman subjects by using a procedure which was more nearly analogous to the simple conditionjng experiments with animals than the procedures with human subjects which had been previously employed. Thus, not only was the experimental task designed to resemble the instrumental running response of the rat in the "straightaway," but in the same way that magnitude of the reward which the rat receives in the goal box is typically not dependent upon the "quality" or "speed" of its' performance, no such contingency held in the present procedure.…”