A Computational Model of Intertemporal Choice: Exploring the Impact of Sleep Deprivation on the Discounting of Future Rewards

Abstract

Sleep has a profound impact on numerous cognitive functions, including decision-making and self-control. However, the precise mechanisms by which sleep influences these processes are not completely understood. This study explored how sleep loss impacts the weighting of short-term and long-term rewards, and thereby influences the decision-making process. Participants self-reported their sleep on the previous night and participated in a decision-making experiment involving 25 choices between pairs of food items, where the taste value of each food item represented short-term reward and the health value of the food represented long-term reward. I hypothesized that participants who slept less would exhibit less self-control and thus would place a lesser weight on health relative to taste; further, I hypothesized that self-control would deplete as trials progress.

I developed four nested computational models to characterize the decision-making process: a baseline model that assumes equal weights for taste and health, a model that fits a health weighting parameter for each participant, and two models that incorporate a linear or exponential decay parameter to simulate potential self-control depletion across trials. The model that fit a βhealth weight for each participant provided the best fit for the data, suggesting that participants vary in how they weigh taste versus health and that this weighting was relatively stable across trials. This study did not find a significant correlation between βhealth and sleep hours under any of the models. While the results did not align with my hypotheses, this may be due to a small sample size, limited variability in sleep duration, computational constraints, and other factors. Further research is needed to better explore this relationship, potentially with more extreme manipulations of sleep or the consideration of additional factors that may influence intertemporal choice.