Comparison of Pavlovian serial conditional discrimination in rats and hamsters in the same experimental situation

Abstract

The present study compares behavioral changes between two distinct rodent groups, hamsters (Mesocricetus auratus) and Wistar rats, when submitted in the same homogeneous experimental situations to a serial conditional discrimination procedure which involves water deprivation and the processing of temporal variables. Both hamsters and rats acquired serial positive conditional discrimination as indicated by higher frequencies of magazine-oriented behavior during the tone followed by reinforcement (T+) and preceded by the feature stimulus light (L) and during the empty interval, than during the tone alone not followed by reinforcement (T-). Rats' frequencies of magazine-oriented behavior were high during T+ and T-, initially during training, and decreased during T-as the training progressed. However, the hamsters' frequencies of magazine-oriented behavior started very low and increased only during T+ as the training progressed. Comparison of the frequencies of magazine-oriented behavior during the empty interval in relation to the frequencies during the preceding L period showed that rats' frequencies remained very high and hamsters' frequencies increased during training. These results suggest that rats and hamsters have different behavioral strategies for the acquisition of a conditional discrimination. The results of the comparisons made in these experiments support the view of the importance of an ecological psychology approach to the understanding of complex learning in animals. Correspondence

O efeito da omissão de reforço no repertório de ratos com lesão no complexo basolateral e no núcleo central da amígdala

“…The replacement of schedules, in which one or a few responses are recorded by schedules in which the behavioral repertoire is a set of dependent variables, seems to be extremely useful for the study of the underlying processes of behavior (Ades, 1976). Bueno, Figueiredo and Melo (2001) show, for example, that different types of rodents (Wistar rats and Hamsters) have different behavioral strategies when subjected to procedures of conditional discrimination. The results show that the animals have different strategies for the acquisition of a conditional discrimination, as well as highlight the importance of a psychoethological approach for the understanding of complex learning in animals.…”

Efeitos da omissão do reforço sobre o repertório comportamental em ratos com lesão do núcleo accumbens

“…Em outro estudo (Bueno & Kandratavitius, 1986) animais eram submetidos a esquemas de intervalo-fixo onde, após treino prolongado e com CS de diferentes durações, os efeitos de omissão não persistiram. Os resultados deste trabalho, assim como os de Bueno et al (2001) demonstraram, através de seus procedimentos, a natureza das associações. Segundo os autores, diferentes estímulos condicionados podem evocar respostas condicionadas diferentes.…”

“…Os trabalhos desenvolvidos pelo laboratório envolvendo repertório comportamental puderam avaliar vários aspectos da análise de um conjunto amplo de categorias comportamentais, e como as estratégias podem variar de acordo com as propriedades modulatórias de estímulos presentes ou não (Ades & Bueno, 1974;Bueno, 1977), procedimentos de discriminação condicional (Moreira & Bueno, 2003;Bueno et al, 2007) e "occasion-setting" (Bueno & Holland, 2008), além de ressaltarem as diferenças de características específicas entre espécies (Bueno et al, 2001). Estes trabalhos em conjunto, além de se mostrarem eficazes na verificação de fatores moduladores do comportamento, mostraram também a importância do repertório comportamental como indicador de processos atencionais e motivacionais.…”