Abstract: | In 3 experiments, the effect of adding an irrelevant stimulus to a discrimination was examined. In Exp 1, a group of pigeons received autoshaping with an A+Bo discrimination in which 1 stimulus signaled food, A+, and a simultaneous compound of A with another stimulus, B, signaled the absence of food, ABo. A 2nd group received similiar training, except that a 3rd stimulus, C, was present in both types of trials, AC+BCo. The A+Bo discrimination was acquired more readily than the AC+BCo discrimination. Exps 2 and 3 used a negative-patterning design, A+Bo+. In both experiments, this problem was mastered more readily than when an irrelevant stimulus was used to create an AC+BCoC+ discrimination. The results fail to confirm predictions derived from elemental theories of conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |