Evaluation of drowsiness during prolonged sleep deprivation

Area of Science:

• Military Medicine
• Neuroscience
• Human Performance

Background:

• Prolonged sleep deprivation is common in military settings like training and warfare.
• Understanding the physiological and performance impacts of sleep loss is crucial for operational effectiveness.

Purpose of the Study:

• To assess the effects of 60-hour sleep deprivation on drowsiness and psychomotor performance in healthy volunteers.
• To identify objective and subjective measures indicative of sleepiness during extended wakefulness.

Main Methods:

• A 60-hour sleep deprivation experiment was conducted on eight French Air Force volunteers.
• Drowsiness was assessed using behavioral questionnaires, Mean Sleep Latency (MSLT), electroencephalogram (EEG) recordings, and psychomotor tests.
• Performance was evaluated by monitoring response failures and control losses during repeated tests.

Main Results:

• A progressive decline in arousal levels was observed across all subjects and tests.
• Drowsiness became evident after 24 hours of uninterrupted wakefulness, consistent with existing literature.
• Microsleep episodes significantly degraded psychomotor performance, highlighting the detrimental effects of sleep loss.

Conclusions:

• Sixty hours of sleep deprivation leads to significant decrements in arousal and psychomotor performance.
• The study confirms that drowsiness emerges after 24 hours of wakefulness, impacting operational capabilities.
• Microsleep episodes are a key mechanism through which sleep deprivation impairs performance.