Discriminação Simples em Ratos com Três Tipos de Contingências Supressivas em Sdelta: Choque Elétrico X Jato de Ar Quente X Extinção

Abstract

Traditionally, simple discrimination is established using positive reinforcement in the SD condition and extinction in SDelta. Some studies have added positive punishment in SDelta, such as electric shock (SHO) or hot air blast (HAB). Such studies not only produced discrimination, but they did it in a smaller number of sessions and with a more accurate discriminative index (DI). The aim of the present study was to compare the effects of SHO and HAB in producing simple discrimination in rats, trying to separate (a) facilitation by the use of a specific aversive stimulus, (b) from facilitation as a general effect of simple adoption of an aversive contingency in training. Nine rats were used whose responses were reinforced with food in SD. In SDelta, in turn, the animals were divided into three groups: extinction (GEXT), extinction + punishment with HAB (GHAB) and extinction + punishment with electric shock (GSHO). The data showed that the GHAB subjects learned with a smaller number of sessions (at most 3) and with a higher DI (at least 79.31%). The GEXT subjects, in turn, needed at least 8 sessions to learn the same task and the best DI was 77.47%. There were technical problems in the GSHO and only one subject learned the task (8 sessions with an DI of 77.99%). The comparison between the two aversive stimuli could not be done as planned, but the valid HAB data replicate previous results that pointed out that the addition of a punishment contingency to an extinction arrangement facilitates the acquisition of simple discrimination when compared to the traditional procedure. Changes in the procedure with SHO are suggested based on the observed problems.