Search results
Results from the WOW.Com Content Network
It is used to measure the time it takes from the start of a daytime nap period to the first signs of sleep, called sleep latency. Subjects undergo a series of five 20-minute sleeping opportunities with an absence of alerting factors at 2-hour intervals on one day.
In individuals deprived of sleep, somnolence may spontaneously dissipate for short periods of time; this phenomenon is the second wind, and results from the normal cycling of the circadian rhythm interfering with the processes the body carries out to prepare itself to rest. The word "somnolence" is derived from the Latin "somnus" meaning "sleep".
In a perfect world, most of us should take 10 to 20 minutes to fall asleep, with the average sleep latency (the time it takes to fall asleep) sitting at about 12 minutes.But alas, this world is ...
REM sleep, also known as paradoxical sleep, represents a smaller portion of total sleep time. It is the main occasion for dreams (or nightmares), and is associated with desynchronized and fast brain waves, eye movements, loss of muscle tone, [20] and suspension of homeostasis. [21]
(In faster-developing mammals, this process occurs in utero.) [57] Infants spend more time in REM sleep than adults. The proportion of REM sleep then decreases significantly in childhood. Older people tend to sleep less overall, but sleep in REM for about the same absolute time (and therefore spend a greater proportion of sleep in REM). [58] [45]
A sleep diary can be used track time to bed, total sleep time, time to sleep onset, number of awakenings, use of medications, time of awakening, and subjective feelings in the morning. [95] The sleep diary can be replaced or validated by the use of out-patient actigraphy for a week or more, using a non-invasive device that measures movement. [96]
The word hypnagogia is sometimes used in a restricted sense to refer to the onset of sleep, and contrasted with hypnopompia, Frederic Myers's term for waking up. [2] However, hypnagogia is also regularly employed in a more general sense that covers both falling asleep and waking up.
Sleep-talking can also be caused by depression, sleep deprivation, day-time drowsiness, alcohol, and fever. It often occurs in association with other sleep disorders such as confusional arousals, sleep apnea, and REM sleep behavior disorder. In rare cases, adult-onset sleep-talking is linked with a psychiatric disorder or nocturnal seizure. [2]