Interaction of Chronic Sleep Restriction and Circadian Misalignment on Sleep and Neuro-cognitive Performance

Study Overview
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Brief Summary
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The primary objectives of the proposed experimental and modeling efforts are to quantify the influences of acute sleep deprivation (short-term homeostatic), chronic sleep restriction (long-term homeostatic), circadian rhythmicity, and their interactions on neurocognitive performance and to develop a new model of sleep homeostasis that can predict the effects of chronic sleep restriction. This model will be based on the underlying neuroanatomy and neurophysiology. This new model will facilitate optimization of human performance in operational settings, such as are seen in military operation and other work environments.

Detailed Description
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This protocol involves a baseline period consisting of 14 hours of wakefulness and 10 hour nocturnal sleep episodes each 24 hours. This is followed by a forced desynchrony regimen spanning 21 calendar days and consisting of 12 cycles (days) of a 42.85-hour wake:bedrest schedule. In each 42.85 hour cycle, there are 32.85 hours of scheduled wakefulness and 10 hour sleep opportunities. This will allow assessment of the independent contributions of circadian phase and homeostatic sleep pressure on sleep and neurobehavioral performance. This forced desynchrony regimen is followed by 10 recovery days consisting of 14 hours of wakefulness and 10 hour nocturnal sleep episodes each 24 hours.

Official Title
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Interaction of Chronic Sleep Restriction and Circadian Misalignment on Sleep and Neuro-cognitive Performance

Conditions
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Healthy

Intervention / Treatment
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* Behavioral: forced desynchrony protocol with sleep restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-35 years old Medically healthy Exclusion Criteria: Sleep disorder Psychiatric illness Chronic medical condition No prescription or Non-prescription medications

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Behavioral: forced desynchrony protocol with sleep restriction|Subjects are scheduled to live on a non-24 hour day. This separates the sleep-wake schedule from the near-24 hour circadian rhythm. This allows assessment of how circadian rhythms and the length-of-time awake contribute to sleepiness, alertness, and cognitive performance.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleep Stage |  | 38 days | 
| Circadian Phase (melatonin rhythm) |  | 38 days | 
| Psychomotor Vigilance Task |  | 38 days | 
| Digit Symbol Substitution Task |  | 38 days | 
| Addition Task |  | 38 days | 
| Karolinska Sleepiness Scale |  | 38 days | 
| Karolinska Drowsiness Test |  | 38 days | 
| Mood Scales |  | 38 days | 
| Flanker Task |  | 38 days | 
| Multiple Object Tracking |  | 38 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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forced desynchrony, circadian rhythms, sleep restriction, sleep homeostasis, neurobehavioral performance