Abstracts

TL;DRAbstract

In the two-process model as developed in the early 1980's sleep is controlled by a process-S, representing the rise and fall of sleep demand resulting from prior sleep-wake history, interacting with a process-C representing circadian variation in sleep propensity. S and C together optimize sleep timing and intensity with respect to internal demand and external opportunity. The theoretical distinction between S and C has been useful in understanding many aspects of sleep, most prominently 'internal desynchronization' and circadian vs. homeostatic aspects of physiology. Both S and C concepts met difficulties as they were further explored in mathematical detail. The simple S dynamics of the model became problematic when SWA dynamics appeared to vary between brain areas. The C process was originally identified with the circadian pacemaker in the SCN. Some researchers even specifically attributed the direct control of activity and rest to the SCN. Yet, activity-rest rhythms under special ci

Chat with Paper

AI Agents for this Paper