Aversividade do Timeout em uma Situação de Escolha

Abstract

The timeout (TO) procedure is classically described as a form of negative punishment, in which the response temporarily removes access to reinforcers. Despite its widespread use in applied and experimental contexts, there remain conceptual and empirical gaps regarding the mechanisms underlying its effects on behavior. Study 1 of this thesis presented a theoretical analysis of TO in light of four contemporary models of choice and reinforcement value: Delay Reduction Theory (DRT), Hyperbolic Value-Added (HVA), Information Theory, and SiGN. The discussion showed that TO does not act solely by simply removing reinforcement, but systematically modifies the temporal structure of contingencies, altering both the average delays to reinforcement and the amount of information conveyed by signaling stimuli. Thus, TO can produce effects that resemble punishment, but also perform a discriminative and modulatory function on reinforcement expectancy. Study 2 presented four empirical experiments that investigated the effects of different durations and rates of TO presentation in competing schedules with Wistar rats. In Experiment 1, the duration of the TO (5 s, 20 s, and 60 s) was manipulated in VI 20 s – 20 s competitors, with s in response rate across durations, but without a major impact on the preference for the option without a TO. Experiment 2 tested the TO presented in VI (5 s) across different durations (5 s and 20 s), confirming that the presence of TO decreased the response rate to the associated alternative, but again with no clear effect of duration on response allocation. Experiment 3, conducted in competing chains, replicated this pattern, showing a preference for the alternative without TO, but without robust differences between short and long durations. Finally, Experiment 4 varied the TO presentation rate (3 s, 5 s, and 10 s), demonstrating that the higher the TO frequency, the greater the avoidance of the associated option, indicating that the TO rate, rather than its duration, is the critical variable for modulating choice. However, the TO duration proved to be a consistent factor in altering the response rate. Together, the two studies advance understanding of TO on two complementary fronts. From a theoretical point of view, they argue that delay and information models provide useful bases for interpreting the effects of TO but lack refinement when applied to simple choice procedures and parametric manipulations of TO. From an empirical point of view, the results suggest that the aversiveness of TO is not linearly related to its duration, but rather to its frequency of occurrence and the way it reorganizes the temporal flow of reinforcements. These findings indicate that TO should be understood not only as a contingency of suppression, but also as an event that alters the informational and temporal structure of the environment, modulating choices as a function of relative delay and the predictability of reinforcements. This perspective paves the way for future investigations that articulate the effects of TO with formal models of choice, exploring the interaction between delay, signaling, and information, in search of a more comprehensive conceptual framework to explain its effects in both experimental and applied contexts.