Simultaneous brightness discrimination and reversal: the effects of amphetamine administration in the two stages.
Rats were trained in a Y-maze on a two-choice simultaneous brightness discrimination with light as S+ and dark as S- (Stage 1), and were then switched to reversal, where the reinforcement contingencies of the original training were reversed (Stage 2). d-Amphetamine, 1 mg/kg, was administered in a 2 X 2 design, i.e., drug-no drug in Stage 1 and drug-no drug in Stage 2. The administration of the drug in Stage 1 improved the acquisition of the initial brightness discrimination and facilitated reversal learning independently of the drug administered in Stage 2. In addition, the administration of the drug in Stage 2 only improved performance towards the end of reversal training. The results indicate that amphetamine enhances the attention to, or the associability of, the discriminative stimuli, leading to a rapid learning to these stimuli under changed contingencies of reinforcement.
D000818:Animals; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D004193:Discrimination Learning / Q000187:drug effects*; D005260:Female; D007274:Injections, Intraperitoneal; D008027:Light; D051381:Rats; D012193:Reversal Learning / Q000187:drug effects*
D003913:Dextroamphetamine