Managing neurobehavioral capability when social expediency trumps biological imperatives.

Sleep, which is evolutionarily conserved across species, is a biological imperative that cannot be ignored or replaced. However, the percentage of habitually sleep-restricted adults has increased in recent decades. Extended work hours and commutes, shift work schedules, and television viewing are particularly potent social factors that influence sleep duration. Chronic partial sleep restriction, a product of these social expediencies, leads to the accumulation of sleep debt over time and consequently increases sleep propensity, decreases alertness, and impairs critical aspects of cognitive functioning. Significant interindividual variability in the neurobehavioral responses to sleep restriction exists-this variability is stable and phenotypic-suggesting a genetic basis. Identifying vulnerability to sleep loss is essential as many adults cannot accurately judge their level of impairment in response to sleep restriction. Indeed, the consequences of impaired performance and the lack of insight due to sleep loss can be catastrophic. In order to cope with the effects of social expediencies on biological imperatives, identification of biological (including genetic) and behavioral markers of sleep loss vulnerability as well as development of technological approaches for fatigue management are critical.