Prolonged exertion of self-control causes increased sleep-like frontal brain activity and changes in aggressivity and punishment

Impulsive reactions in social interactions may result in poor or detrimental outcomes. Cognitive states such as mental fatigue induced by extended practice with cognitively demanding activities, especially combined with sleep restriction or deprivation, appear to impair self-control and may lead to impulsive behaviors, including aggression. We demonstrate that exertion of self-control for about 45 minutes increases the propensity to engage in aggressive acts in socially relevant choices, measured via economic games. These behavioral changes are associated with increased sleep-like (delta) activity within frontal brain areas implicated in decision-making and impulse control. Local occurrence of sleep-like slow waves may disengage frontal areas and explain reduced self-control. Our results suggest that sleep-like activity can emerge in the awake brain on relatively short timescales, with detectable effects on socially relevant behavior.