SUCCESSIVE POSITIVE CONTRAST WITH BITTER SOLUTIONS: EUPHORIA RESPONSES IN AVERSIVE CONTEXTS

AVELLANEDA, M.; SERAFINI, M.; KAMENETZKY, G.

Encuentro virtual

Congreso; XXXII International Conference of the Society for Comparative Psychology (SEPC); 2021

Sociedad Española de Psicología Comparada (SEPC)

Positive incentive contrast is a phenomenon observed when a group of subjects exhibits a higher consumption of a reinforcer, compared to a control group, under the condition of having been previously exposed to a similar reinforcer of lower magnitude. Traditionally, this effect is studied with rats using sweet solutions. This preparation, even though widely used, does not consistently result in this effect. However, a positive incentive contrast effect was recently reported using bitter solutions instead of sweet ones. On the other hand, the presence of a familiar odor has been shown to be effective in attenuating the responses elicited by aversive stimuli, a phenomenon denominated social buffering. This experiment was designed to study whether the presence of a familiar odor decreases the rejection responses towars bitter solutions in the context of positive incentive contrast. To extend the findings of previous studies, we used a quinine solution of 0.2% during the preshift phase. Two groups of rats received solutions of 0.2% (experimental group) and 0.01% (control group) quinine during the preshift phase. During the postshift phase, the solution of the former was replaced by that of 0.01%, and half of the subjects in each group were tested in the presence of the homecage?s odor. A positive incentive contrast was observed among the subjects of the experimental group, which consumed more of the low-concentration solutions during the postshift phase than the control group. The presence of the odor, however, exerted no effect. These results replicate and extend previous findings of positive incentive contrast with bitter solutions to a higher concentration but suggest the homecage?s odor is not effective in attenuating the responses that these solutions elicit. The latter finding may be due to the solutions used being too aversive for their rejection to be attenuated, or to the social buffering effect not being applicable to this context.