Attention & Vigilance
topic
Sustained attention and vigilance — the ability to maintain alert, responsive processing over extended periods — are among the first and most severely impaired cognitive functions under sleep deprivation, with reaction time variability (the frequency of lapses in sustained attention) being the most sensitive single measure of sleep-deprivation cognitive impairment, increasing predictably with both total sleep deprivation and chronic partial restriction in ways that map directly onto real-world accident and error risk.
Role
Sustained attention degradation from sleep deprivation is the mechanism behind the majority of drowsy driving accidents, medical errors in fatigued healthcare workers, and industrial accidents in shift workers — and it is almost entirely invisible to the individual experiencing it. The repeatedly documented finding that sleep-deprived individuals cannot accurately assess their own attentional impairment — while external performance measures show clear degradation — represents the most dangerous combination possible for high-stakes vigilance-dependent work: impaired performance combined with confident self-assessment of adequate performance.