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 bi-hourly on a variant of the Psychomotor Vigilance Test during 41 h of sleep deprivation.

Effects of dextroamphetamine, caffeine and modafinil on psychomotor vigilance test performance after 44 h of continuous wakefulness.

Prolonged sleep loss impairs alertness, vigilance and some higher-order cognitive and affective capacities. Some deficits can be temporarily reversed by stimulant medications including caffeine, dextroamphetamine, and modafinil. To date, only one study has directly compared the effectiveness of these three compounds and specified the doses at which all were equally effective in restoring alertness and vigilance following 64 h of wakefulness.

Ampakine (CX717) effects on performance and alertness during simulated night shift work.

Introduction: Round-the-clock operations in both military and civilian sectors have increased the need for alertness- and performance-maintaining strategies. The potential performance and objective alertness-enhancing effects of CX717 (a novel cognitive enhancer currently being tested in Phase II clinical trials) were evaluated using a simulated night shift work paradigm.

Methods: In this randomized, double-blind, placebo-controlled, parallel groups design, 48 volunteers underwent 4 consecutive nights of simulated shift work.

Daytime sleep and performance following a zolpidem and melatonin cocktail.

Study Objectives: Pharmacologic enhancement of daytime sleep may help sustain optimal cognitive performance. At effective doses, zolpidem induces sleep but also impairs performance. Combining melatonin with low-dose zolpidem may promote daytime sleep without exacerbating performance impairments seen with high-dose zolpidem alone.

Maintaining alertness and performance during sleep deprivation: modafinil versus caffeine.

Rationale: The performance and alertness effects of modafinil were evaluated to determine whether modafinil should replace caffeine for restoring performance and alertness during total sleep deprivation in otherwise healthy adults.

Objectives: Study objectives were to determine (a) the relative efficacy of three doses of modafinil versus an active control dose of caffeine 600 mg; (b) whether modafinil effects are dose-dependent; and (c) the extent to which both agents maintain performance and alertness during the circadian trough.

Methods: Fifty healthy young adults remained awake for 54.