Sleep Trivia

Since we all seem to suffer from sleep-related events…
I recommend the following book; it contains many interesting facts and is extremely helpful to know the influence of sleep on well being.
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About Sleep Debt:
A test for measuring sleep load was termed the Multiple Sleep Latency Test. The MSLT is the amount of time it takes for the person to fall asleep from (0 – 20). They found a direct linear relationship between the average amount of sleep lost and the average change in MSLT scores. They used this test to conclude another result,
“The brain keeps an exact accounting of how much sleep it is owed. In our first study, we restructed the sleep of 10 volunteers to exactly 5 hours each night for 7 nights and observed that the tendency to fall asleep increased progressively each successive day. For the first time in the history of sleep research, we discovered that the effect of each successive night of partial sleep loss carried over, and the effect appeared to accumulate in a precisely additive fashion. In other wods, the strength of the tendency to fall alssep was progressively greater during each successive day with exactly the same amount of sleep each night…” (Dement, 60).

However, this area still needs a more research because there are not enough studies on how long the brain retains an account of our sleeping debts.

The Sleep Cycle

The first round of REM comes after deep sleep.

Stage 1 and Stage 2: The theta waves of light sleep.
Stage 3 and 4: Deep sleep
“In a normal night's sleep, a sleeper begins in stage 1, moves down through the stages, to stage 4, then back up through the stages, with the exception that stage 1 is replaced by REM, then the sleeper goes back down through the stages again. One cycle, from stage 1 to REM takes approximately ninety minutes. This cycle is repeated throughout the night, with the length of REM periods increasing, and the length of delta sleep decreasing, until during the last few cycles there is no delta sleep at all”
http://web.mst.edu/~psyworld/general/sleepstages/sleepstages.pdf