Research

Hormonal

The detrimental effects of sleep deprivation on cognitive performance are modulated by circadian phase, being virtually absent during the evening wake maintenance zone and most prominent during early morning hours.

Do not rely on feeling 'fine' in the evening to judge your sleep debt. Your circadian drive masks the effects of sleep loss during the evening. Plan critical tasks for the morning or afternoon, and avoid high-stakes decisions late at night or early morning when circadian and homeostatic pressures align to maximize impairment.

StrongQualifiesVERY_HIGH confidence
prior partial sleep deprivation led to poorer cognitive performance in a subsequent total sleep deprivation period, but its effect was modulated by circadian phase such that it was virtually absent in the evening wake maintenance zone, and most prominent during early morning hours.
June C. Lo et al. · PLoS ONE · 2012

Why this rating

Controlled laboratory protocol with precise circadian alignment.

Source

Effects of Partial and Acute Total Sleep Deprivation on Performance across Cognitive Domains, Individuals and Circadian Phase

June C. Lo et al. · PLoS ONE · 2012

DOI 10.1371/journal.pone.0045987

crossover · n=36Cited 331×
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DOI resolved against Crossref · corpus check 2026-06-10

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