How Sleep Need and Internal Body Clock Together Predict Daytime Brain Performance

Evidence from a laboratory experiment shows a non-linear interaction between homeostatic and circadian processes in sleep-wake regulation.

• The two-process model of sleep regulation has been applied to various experimental protocols, including sleep deprivation.
• Alertness and performance data during forced desynchrony revealed a non-linear relationship between homeostatic and circadian processes.
• This non-linear interaction may also stem from the intrinsic non-linearity in the metrics used to measure alertness and performance.
• The findings could influence the design and interpretation of experiments involving different sleep durations and circadian phases.
• Data sets from total sleep deprivation experiments were utilized to examine the interaction between sleep regulation processes.

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