The Effects of Correlated Color Temperature on Risky Decision-Making in Fatigued Individuals: An Event-Related Potential Study

Objective This study investigated the effects of correlated color temperature (CCT) on risky decision-making in fatigued individuals and the potential neural mechanisms underlying these effects. Background Underground facilities (UGFs) are increasingly utilized as military shelters, but the environmental stressors within them can easily lead to mental fatigue among commanders. The blue component within polychromatic white light, as indexed by CCT, has been shown to enhance alertness and cognition through non-visual pathways mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs). However, it remains unclear whether CCT can benefit risky decision-making in fatigued individuals during the day. Method We examined the effects of varying CCTs (4000 K, 6500 K, 8500 K, 12,000 K) on fatigued individuals using a within-subjects design ( N = 21) and assessed subjective alertness and mood, behavioral performance in attention and risky decision-making, and event-related potentials (ERP), including feedback-related negativity (FRN) and the P300 component. Results The results showed that 12,000 K led to more favorable decisions, reflected by a lower risk ratio, more cash-outs, and higher revenue. ERP analyses revealed larger FRN and P300 amplitudes under 12,000 K, indicating that higher CCT enhanced cognitive control and promoted more conservative decision-making, enabling beneficial feedback-based decisions even under fatigue. Conclusion Blue-enriched white light improves alertness, mood, and decision-making in fatigued individuals, promoting gain-maximizing and risk-minimizing decisions. Application The current findings demonstrate that CCT may serve as a key parameter for light-based interventions aimed at alleviating fatigue in risky decision-making in UGFs.