SWS rebound

From Polyphasic Sleep Wiki

SWS (Slow-wave sleep) rebound is the lengthening and increase in frequency and depth of SWS after periods of sleep deprivation. A longer duration of time spent in SWS, as well as a significant shortening of NREM3 latency are common signs of an SWS rebound, as a study on a selective slow-wave sleep deprivation has shown.[1]

Sleep-onset SWS

Normally, SWS only occurs around 20-30 minutes into a sleep cycle. However, during the process of SWS rebound, SWS latency shortens, meaning that the body reaches SWS sooner. This phenomenon is known as sleep-onset SWS, or SOSWS.


  1. Ferrara M, De Gennaro L, Bertini M (1999). "Selective slow-wave sleep (SWS) deprivation and SWS rebound: do we need a fixed SWS amount per night". Sleep research online. 2 (1): 15–19.