Executive Functions and the Ability to Sustain Vigilance During Sleep Loss

Introduction: There is considerable individual variability in the ability to sustain performance during sleep loss. Preliminary evidence suggests that individuals with higher trait-like activation/functioning of the prefrontal cortex may be less vulnerable to fatigue. Methods: We tested this hypothesis in a sample of 54 healthy volunteers who were assessed hourly, oil a variant of the Psychomotor Vigilance Test during 41 h of sleep deprivation. A subset of these subjects, representing the top and bottom 25%, of the sample based on their ability to sustain vigilance performance during sleep deprivation, were compared with respect to baseline neurocognitive abilities. Results: The sleep deprivation Resistant group (N = 13) scored significantly higher than the sleep deprivation Vulnerable (N = 13), group on all three baseline tasks assessing prefrontal executive function abilities (letter fluency, Stroop Color-Word test, Color Trails Form 2), whereas no differences were found on non-executive function tasks. Similarly, groups showed differences on demographic variables Including age, education, hand preference, morningness-eveningness preference, global intellectual ability, or pre-study sleep history. Discussion: Findings are consistent with the hypothesis that greater prefrontal/executive functioning may he protective against the adverse effects of sleep deprivation and suggest that baseline executive function testing may prove useful for prediction of resilience during sleep loss.