| Description |
In this study, our objectives were to 1) Examine performance on an objective measure of reward-related cognitive impulsivity (delay discounting) among self-reported habitual short sleepers not reporting daytime dysfunction in comparison to those reporting dysfunction and conventional sleepers; 2) Inform the debate regarding what type and duration of short sleep meaningfully influences cognitive impulsivity; 3) Compare the predictive utility of sleep duration and perceived daytime dysfunction to other factors previously shown to influence cognitive impulsivity via delay discounting performance (age, income, education, and fluid intelligence). We analyzed data from 1,190 adults from the Human Connectome Project database. Participants were grouped on whether they reported habitual short (≤ 6 hours) vs. conventional (7 to 9 hours) sleep duration and whether they perceived daytime dysfunction using the Pittsburgh Sleep Quality Index. Results indicated that short sleepers not reporting dysfunction evidenced increased delay discounting compared to conventional sleepers, but were not significantly different from short sleepers reporting dysfunction. Regardless of perceived dysfunction, all short sleepers exhibited increased delay discounting compared to all conventional sleepers. Of the variables examined, self-reported sleep duration was the strongest predictor of delay discounting behavior between groups and across all 1,190 participants. We conclude that individuals who report habitual short sleep are likely to exhibit increased reward-related cognitive impulsivity regardless of whether they perceive sleep-related daytime impairment. Therefore, there is reason to suspect that these individuals exhibit more daytime dysfunction, in the form of reward-related cognitive impulsivity, than they may assume. Current findings suggest that assessment of sleep duration over the prior month has meaningful predictive utility for human reward-related impulsivity. |
