Stress, mental health, and cognition: a brief review of relationships and countermeasures.

Today's network-centric battlefield environment is highly stressful and cognitively demanding. Many warfighters are feeling overwhelmed and end up being medically evacuated from theater due to mental health problems [i.e.

Neurocognitive monitors: toward the prevention of cognitive performance decrements and catastrophic failures in the operational environment.

Network-centric doctrine and the proposed C41SR (command, control, communications, computers, intelligence, surveillance and reconnaissance) distributions to the individual warfighter require that the cognitive performance, judgment, and decision making of warfighters must be sustained and effectively managed in the forward operating environment, where various physiological and psychological stressors abound, in order to reduce human errors and catastrophic failures. The U.S.

Considerations of pharmacology on fitness for duty in the operational environment.

Coordination of strategies for transitioning psychoactive pharmacological compounds from basic laboratory research to the field environment has been an ongoing effort among military laboratories. Several workshops have been held specifically to address the operationally relevant issues and other military and scientific challenges as they relate to the enhancement and sustainability of cognitive performance. In this preface, we tie together recommendations of the Pharmacological Strategies Focus Team for one such Workshop, review current literature, and discuss findings reported at recent professional meetings.

Operational implications of varying ambient light levels and time-of-day effects on saccadic velocity and pupillary light reflex.

Changes in maximal saccadic velocity (SV), initial pupil diameter (IPD), constriction latency (CL) and constriction amplitude (CA) determined by the pupillary light reflex have been found to be sensitive indicators of impairment as a result of drugs, sleepiness, and/or fatigue. Ambient illuminance and time of day are controlled when these indices are applied as repeated measures in fitness-for-duty determinations. The application of oculometrics in unrestricted operational environments, where ambient illuminance and time-of-day testing are not constant, requires understanding of, and potential compensation for, the effects of, and interactions among, these multiple uncontrolled variables.

Oculomotor responses during partial and total sleep deprivation.

Introduction: Oculomotor responses related to the pupil light reflex (PLR) and saccadic velocity may be sensitive to the effects of sleepiness and therefore could be used to evaluate an individual's fitness for duty.

Methods: There were 12 normal subjects who completed an 8-d study. They were allowed 8 h in bed on the first three nights, 4 h in bed on the fourth night, and then were sleep deprived for the following 64 h.

Monitoring and predicting cognitive state and performance via physiological correlates of neuronal signals.

Judgment, decision making, and situational awareness are higher-order mental abilities critically important to operational cognitive performance. Higher-order mental abilities rely on intact functioning of multiple brain regions, including the prefrontal, thalamus, and parietal areas. Real-time monitoring of individuals for cognitive performance capacity via an approach based on sampling multiple neurophysiologic signals and integrating those signals with performance prediction models potentially provides a method of supporting warfighters' and commanders' decision making and other operationally relevant mental processes and is consistent with the goals of augmented cognition.

Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: a sleep dose-response study.

Daytime performance changes were examined during chronic sleep restriction or augmentation and following subsequent recovery sleep. Sixty-six normal volunteers spent either 3 (n = 18), 5 (n= 16), 7 (n = 16), or 9 h (n = 16) daily time in bed (TIB) for 7 days (restriction/augmentation) followed by 3 days with 8 h daily TIB (recovery). In the 3-h group, speed (mean and fastest 10% of responses) on the psychomotor vigilance task (PVT) declined, and PVT lapses (reaction times greater than 500 ms) increased steadily across the 7 days of sleep restriction.