Efeitos de uma linha de base estável sobre uma resposta operante em condição de extinção precedida por punição em ratos

Abstract

Skinner (1938) reported one of his experiments in which he investigated the process of punishment and extinction. Eight experimental subjects underwent operant conditioning of a pressure response to the bar and were subsequently divided into two groups exposed to extinction of the operant response for 240 minutes (two 120-minute sessions). For the experimental group, the first 10 minutes of the first session presented contingent punishment. The suppressive effects of punishment disappeared after the second extinction session. At the end of the experiment, the experimental group and control gave similar responses. There is no consensus in the area about the study, few authors have replicated it. Study 1 aimed to modify the baseline used by Skinner (1938) for VI-4min. Some change in response was observed, but there was no statistically significant difference between the groups. Study 2 replicates Skinner's study (1938) ensuring a stable baseline prior to the extinction phase. Six female albino rats (Rattus norvegicus, Wistar strain) undergoing bar pressing (one session), strength of CRF response (2 30-minute sessions), and LS schemes of 10s, 20s, and 30s (60-minute sessions). The last scheme was maintained until reaching the criterion of stability: 15% between sessions in the last five sessions and 12% of range. After reaching stability, Skinner's experimental procedure (1938), punishment extinguishment sessions for the experimental group, with Hot Air Jet (JAQ) as an aversive stimulus and the addition of three reconditioning sessions were followed. The experiment, modifying the baseline, replicated the results obtained by Skinner. It is possible to affirm, from this study, that the suppressive effects disappear. The punished group presented no response greater than the control group, but issued responses throughout the sessions, decreasing the difference of the groups until the end of the second extinction session. In the reconditioning, there was no significant difference between the groups.