In this study, we aimed to determine whether 21-hour continuous wakefulness decreases performance in the Iowa Gambling Task and examine the effect of the interaction between a weak emotional stressor and prolonged continuous wakefulness on the decision-making process, as measured by the Iowa Gambling Task. Approximately half of 38 healthy college students were in the sleep deprivation condition (they performed the task at 4:30 a.m.); the remainder were in the daytime condition (they performed the task during the day). The participants in each sleep condition were further divided into non-exposed and exposed to an emotional stressor via a social exclusion procedure before the task, with the Iowa Gambling Task score as the dependent variable. In the sleep deprivation condition, performance in the final block of the task was significantly worse in the group with an emotional stressor than the group without. There was no main effect of sleep conditions or emotional stressors on the task performance in either block. The results of this study suggest that even 21 hours of continuous wakefulness, which can occur in daily work life, may prevent appropriate learning in people exposed to an emotional stressor, even if the stress caused due to it is low.
Keywords: Cognitive performance; Decision-making ability; Learning; Sleepiness; Stressors.