(no subject)
Feb. 6th, 2004 07:44 pm...studies show that the length of sleep is not what causes us to be refreshed on waking. The key factor is the number of compete sleep cycles we enjoy. Each sleep cycle contains fuve distinct phases, which exhibit different brain-wave patterns. [see The Mind in Sleep and Biological Rhythms etc.]. For our purposes, it suffices to say tha one sleep cycle lasts an average of 90 minutes: 65 minutes of normal, or non-REM sleep; 20 minutes of REM sleep (in which we dream); and a final five minutes of non-REM sleep. [The REM cycles are shorter during earlier cycles and longer during later ones]. If we were to sleep completely naturally, with no alarm clocks or other sleep disturbances, we would wake up, on the average, after a multiple of 90 minutes...In the period between cycles, we are not actually sleeping; it is a sort of twilight zone. A person who sleeps only four cycles (6 hours) will feel more rested than someone...who has not been allowed to complete any one cycle.
(from The Owner's Manual for the Brain, Howard, 1994 - cc'd to MC)
no subject
Date: 2004-02-06 05:38 pm (UTC)Re:
Date: 2004-02-07 04:09 pm (UTC)I'm gonna set up some sort of school to teach people useful stuff - how to light fires, make the most of their sleep... that sort of thing :)