Effort Exertion And Good Sleep Interactively Increase The Subjective Value Of The Future

Abstract Introduction The present study examined how habitual variation in sleep quality shapes reward responsivity following effort exertion. Behavioural and neuroscientific theory and research suggest that expending effort leads to compensatory increases in reward responsivity. Converging evidence links the preference for larger-but-delayed rewards to increases in reward sensitivity in psychophysiological, psychopharmacological, and animal studies. Accordingly, we hypothesized that exerting mental effort would increase the preference for larger-but-delayed rewards (i.e., the subjective value of the future) insofar as these preferences reflect elevated reward responsivity. Furthermore, given that sleep shapes perceptions of effort and preferences for larger-but-delayed rewards, we hypothesized that this finding would be moderated by habitual variation in sleep quality, with the strongest effects apparent among participants reporting habitually good sleep. Methods To test these hypotheses, we recruited 79 participants to complete a 10-minute effortful (vs. control) writing task followed by a delay discounting task and the Pittsburgh Sleep Quality Index. Results As hypothesized, the effortful writing task (vs. control) participants demonstrated a greater preference for larger-but-delayed rewards (vs. smaller-but-immediate rewards). This effect was moderated by sleep quality with those high but not low in sleep quality showing the hypothesized effect. Conclusion Ultimately, we found that exerting mental effort increases the subjective value of the future, particularly among participants who habitually report good sleep. These results suggest that good sleep quality helps us contend with the effortful demands of daily life in a way that promotes long-term goal pursuit. Support (if any):