Tired and out of control? Effects of total and partial sleep deprivation on response inhibition under threat and no-threat conditions.

STUDY OBJECTIVES

Sleep deprivation may impair top-down inhibitory control over emotional responses (e.g. under threat). The current study examined the behavioral consequences of this phenomenon and manipulated the magnitude of individuals' sleep deficit to determine effect thresholds.

METHODS

Twenty-four healthy human participants were provided with 0, 2, 4, and 8 hours of sleep opportunity and, subsequently, performed a bimanual anticipatory response inhibition task under threat and no-threat conditions. Behavioral responses (button presses) and surface electromyography (EMG) from task effectors were collected to examine going and stopping processes.

RESULTS

Bayesian analyses revealed that compared to 8 hours of sleep, go-trial accuracy was reduced with 0 hours of sleep. Stopping speed was reduced with 0 and 2 hours of sleep, as evidenced by longer stop-signal delays, but only in a selective stopping context. None of the outcome measures were impacted by 4 hours of sleep. Under threat, go-trial accuracy was maintained, while responses were slightly delayed and characterized by amplified EMG bursts. Stopping speed was increased under threat across both stop-all and selective stopping contexts. No evidence was observed for interactions between sleep and threat.

CONCLUSIONS

Sleep deprivation negatively affected response inhibition in a selective stopping context, with stopping speed reduced following a single night of ≤2 hours of sleep. Performance-contingent threat improved response inhibition, possibly due to a prioritizing of stopping. No evidence was observed for increased threat-related responses after sleep deprivation, suggesting that sleep deprivation and threat may impact inhibitory control via independent mechanisms.