ABSTRACT
Identifying the approximate degree of vulnerability/resistance to sleep loss among individuals would permit a greater utilization of personnel and resources, by providing a way of determining those individuals who need countermeasures early and often and those who can withstand longer periods with little to no sleep. Intrusions of sleep-initiating biology into the neural mechanisms of goal-directed waking performance are evident as increases in a variety of neurobehavioral phenomena: lapses attention, sleep attacks, increased frequency of voluntary naps, shortened sleep latency, slow eyelid closures and slow-rolling eye movements, and intrusive daydreaming while engaged in cognitive work. Wake state instability refers to moment-to-moment shifts in the relationship between neurobiological systems mediating wake maintenance and those mediating sleep initiations Moreover, the differential effects are found even in healthy adults who sleep the same duration each night and otherwise have comparable normal cognitive capability when not sleep deprived. Psychomotor Vigilance Test performance lapses reflect the dynamic interactions of sleep homeostatic drive and circadian neurobiology.
