Molecular Insights Into Chronotype and Time-of-Day Effects on Decision-Making

In the study conducted 7 years ago, researchers investigated the relationship between human decision-making and biological rhythms by examining how time of day and chronotype (whether one is a morning or evening person) affect performance on decision-making tasks. Participants completed two tasks, the matrix task and the balloon analog risk task (BART), either in the morning or evening, and their chronotype was assessed using the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ) and by measuring the expression of circadian clock-regulated genes (Per3 and Nr1d2) in hair follicle samples. The study found that significant differences in decision-making between 'larks' (morning types) and 'owls' (evening types) were only observed when chronotype was determined by RNA-based measures of gene expression, not by self-report. This suggests that individual differences in molecular clockwork may influence decision-making behavior and that these effects are related to the phase of the peripheral clock as indicated by gene expression.