Successive negative contrast effect: Intertrial interval, type of shift, and four sources of generalization decrement.

Abstract

Used 60 male Holtzman rats in a runway to study the successive negative contrast effect, varying both intertrial interval (3-5 min. or 24 hr.) and type of reward shift (transfer vs. nontransfer shift). The negative contrast effect was considerably larger at the 3-5 min. interval. Transfer shift training eliminated the negative contrast effect at the 24-hr interval, merely reducing it at the 3-5 min. interval. These findings are employed to evaluate the relative contribution to the negative contrast effect of 4 separate sources of generalization decrement. (PsycINFO Database Record (c) 2006 APA, all rights reserved)