Effect of Baseline VI on Operant Extinction Preceded by Punishment in Rats

Abstract

Skinner (1938) investigated punishment and extinction in eight experimental sub­jects who underwent operant conditioning of pressure response to the bar and were divided into two groups, exposed to the extinction of the response for 240 minutes (two sessions of 120 minutes). The experimental group received contingent punishment in the first 10 min­utes of the first extinction session. Suppressive effects of the punishment disappeared after the second extinction session. In the end, the experimental and control groups issued similar responses. The present study is based on Skinner (1938), with manipulation at the baseline, modified to a Variable Interval of 4 minutes (VI - 4 minutes). Six albino rats (Rattus norvegi­cus, Wistar lineage) were used, which went through modeling the response of pressing the bar (one session), strengthening the response in continuous reinforcement - CRF (2 sessions of 30 minutes) and VI-4 minutes (3 sessions) 60 minutes). Subsequently, extinction sessions were held, with punishment for the experimental group, using the Hot Air Jet (JAQ), followed by three reconditioning sessions. In the strengthening phase and in the first extinction session, the control group issued more responses than the experimental one. In the second extinction session, the experimental group goes beyond control. At the end of this extinction session, the average cumulative response of the experimental group exceeds the control. In reconditioning sessions, the recovery of responding in the two groups was out of a similar order.