SUCCESSIVE CONTRAST EFFECTS AS A FUNCTION OF TYPE AND MAGNITUDE OF REWARD

Trained 6 groups of 9 naive male albino rats each, 1 trial/day, in a straight runway in order to investigate the effects of a Phase 1 reward condition on S's subsequent behavior in terms of its influence on reward shift (Phase 2) and reacquisition (Phase 3) following either a different reward quality, a different reward magnitude, or an interpolated training with nonreward. A marked depression effect was obtained when the shift was to a qualitatively different reward, e.g., food to water, with a similar reinforcing potency. The reacquisition rate was faster for all conditions of interpolated training when reward was the same in Phases 1 and 3 rather than when it was different. The findings support the sequential hypothesis. (15 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.