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

Abstract

Study objectives: Sleep deprivation may impair top-down inhibitory control over emotional responses (e.g., under threat). The current study examined 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 0hr, 2hr, 4hr and 8hr 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 8hr sleep, go trial accuracy was reduced with 0hr sleep. Stopping speed was reduced with 0hr and 2hr of sleep, as evidenced by longer stop-signal delays, but only in a selective stopping context. None of the outcome measures were impacted with 4hr sleep. Under threat, go trial accuracy was maintained, whilst 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.

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