Acquisition of barpressing in rats following experience with response-independent food

Abstract

In a three-group experiment, one group of rats (response-contingent) learned to contact a food cup for Noyes food pellets delivered according to a fixed-ratio schedule of reinforcement. Subjects in another group received a response-independent pellet each time its yoked counterpart earned one. A third (control) group received the same amount of food as the other two groups each day, but the pellets were delivered in mass. Following this training, the rats were placed in a novel experimental chamber in which all responses on a bar were reinforced with the presentation of food pellets. The results showed the response-independent animals to be slower in acquiring the barpress response than the naive control subjects, and the response-contingent subjects to be the fastest. It has been repeatedly demonstrated that administering response-independent electric shocks to dogs and rats may interfere with their subsequent learning to escape 'rom shock when cornpared with the learning of subjects receiving either prior exposure to escapable shocks or no shocks (e.g.

“Manna from heaven”: The effect of noncontingent appetitive reinforcers on learning in rats

“…Neither the 30-day group nor the "live-in" group differed from the I-day group. Wheatley , Welker, and Miles (1977) had reported that deficits in instrumental responding for food were observed in rats given prior experience with noncontingent food. However, they subsequently reported (Wheatley, Welker, & Miles, 1978) that there had been errors in the statistical analysis and that the differences between the noncontingent and control groups actually were not significant.…”

Interference and facilitation produced by noncontingent reinforcement in the appetitive situation

“…160;Maier& Seligman, 1976)-since response speed remained unaffected. However, thispossibility does not account for the failure to observethe effect in a barpress test (Wheatley et al, 1977) or the observation of a facilitation effect. Therefore, the present series of experiments attempted to establish the conditions under which the interference effect could be observed reliably in the appetitive situation.…”

“…Experiments in which rats have been exposed to uncontrollable appetitive reinforcers have also produced divergent effects, ranging from the interference effect Copyright 1988 Psychonomic Society, Inc. JOB (Oakes, Rosenblum, & Fox, 1982) to failure to observe an effect (Wheatley, Welker, & Miles, 1977, erratum 1978 to facilitation (Beatty & Maki, 1979;Calef et al, 1984). Methodological considerations also render some resultsambiguous.…”

Efeitos da exposição a estímulos aversivos e apetitivos incontroláveis sobre o comportamento verbal em contingências de reforço positivo

“…Capelari e Hunziker (2005) utilizaram um procedimento análogo ao tradicionalmente utilizado no estudo do desamparo com ratos, mas substituíram os estímulos aversivos incontroláveis por estímulos apetitivos incontroláveis. Seus resultados mostraram que a história com estímulos apetitivos incontroláveis não afetou a aprendizagem posterior do comportamento de fuga, achados corroborados por alguns estudos (Beatty & Maki, 1979;Calef et al,1984), mas não por outros (Caspy & Lubow, 1981;Enberg, Welker, Hansen & Thomas, 1972;Ferrándiz & Vicente, 1997;Job, 1987;Sonoda & Hirai, 1992;Welker, 1976;Wheatley, Welker & Miles, 1977). Do mesmo modo como a incontrolabilidade não se encontra suficientemente isolada da natureza do estímulo incontrolável, o papel do uso de choques elétricos no desamparo aprendido também carece de especificação.…”