THE EFFECTS OF FEATURE IDENTITY IN OPERANT SERIAL FEATURE-NEGATIVE DISCRIMINATIONS

The effects of feature identity in an operant serial feature-negative discrimination (F1 double right arrow T1-, T1+) were examined in two e xperiments with rats. rn Experiment 1, rats were trained with two oper ant serial feature-negative discriminations in which different operant s were reinforced during two auditory target cues (T1 and T2). The fea tures (F1 and F2) were two neutral cues (visual or auditory stimuli), two motivationally significant cues (flavored sucrose solutions, also used as the operant reinforcers), or one neutral and one motivationall y significant cue. Experiment 1 showed that discrimination acquisition , transfer performance, and feature-target interval testing were facil itated with a flavored sucrose feature. Experiment 2 showed that flavo red sucrose-alone presentations, more than flavored sucrose trained in a pseudodiscrimination(F1 double right arrow T1+, T1+), shared severa l similarities with a standard flavored sucrose feature. The results s uggest flavored sucrose rapidly acquires inhibitory properties, which facilitates operant serial feature-negative discrimination performance . (C) 1997 Academic Press.