Sex differences and effects of predictive cues on delayed punishment discounting

The majority of the research studying punishment has focused on an aversive stimulus delivered immediately after an action. However, in real-world decision-making, negative consequences often occur long after a decision has been made. This can engender myopic decisions that fail to appropriately respond to consequences. Whereas discounting of delayed rewards has been well studied in both human and animal models, systematic discounting of delayed consequences remains largely unexplored. To address this gap in the literature, we developed the delayed punishment decision-making task. Rats chose between a small, single-pellet reinforcer and a large, three-pellet reinforcer accompanied by a mild foot shock. The shock was preceded by a delay, which systematically increased throughout the session (0, 4, 8, 12, 16 s). On average, rats discounted the negative value of delayed punishment, as indicated by increased choice of the large, punished reward as the delay preceding the shock lengthened. Female rats discounted delayed punishment less than males, and this behavior was not influenced by estrous cycling. The addition of a cue light significantly decreased the undervaluation of delayed consequences for both sexes. Finally, there was no correlation between the discounting of delayed punishments and a traditional reward delay discounting task for either sex. These data indicate that the ability of punishment to regulate decision-making is attenuated when punishment occurs later in time. This task provides an avenue for exploration of the neural circuitry underlying the devaluation of delayed punishment and may assist in developing treatments for substance use disorders