Ⓒ 2020 About, Inc. (Dotdash) — All rights reserved After stage 3 sleep, stage 2 sleep is repeated before entering REM sleep. As a person transitions from being awake to falling asleep, alpha waves are replaced by theta waves. Stage 2 is the second stage of sleep and lasts for approximately 20 minutes.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Once REM sleep is over, the body usually returns to stage 2 sleep.
In terms of brain wave activity, stage 1 sleep is associated with both alpha and theta waves. This stage was previously divided into stages 3 and 4. This period of sleep lasts only a brief time (around five to 10 minutes). Brain waves during REM sleep appear very similar to brain waves during wakefulness. The first cycle of REM sleep might last only a short amount of time, but each cycle becomes longer. The brain produces what are known as beta waves, which are small and fast. During this stage, people become less responsive and noises and activity in the environment may fail to generate a response. There was a significant positive correlation between the degree to which women thought about their former spouses during waking hours and the number of times their former spouses appeared as characters in their dreams (Cartwright, Agargun, Kirkby, & Friedman, 2006). Aside from the role that REM sleep may play in processes related to learning and memory, REM sleep may also be involved in emotional processing and regulation. For instance, REM sleep deprivation has been demonstrated to improve symptoms of people suffering from major depression, and many effective antidepressant medications suppress REM sleep (Riemann, Berger, & Volderholzer, 2001; Vogel, 1975).It should be pointed out that some reviews of the literature challenge this finding, suggesting that sleep deprivation that is not limited to REM sleep is just as effective or more effective at alleviating depressive symptoms among some patients suffering from depression. This is known as the REM rebound, and it suggests that REM sleep is also homeostatically regulated. Sleep begins in Stage One and progresses into stages 2, 3, and 4. (credit “sleeping”: modification of work by Ryan Vaarsi)The first stage of NREM sleep is known as stage 1 sleep. Another very common event during this period is known as a Previously, experts divided sleep into five different stages.
During this time when you are not quite asleep, you may experience strange and extremely vivid sensations known as
Why is this particular explanation unlikely?3. The American Sleep Foundation suggests that people spend approximately 20% of their total sleep in this stage.
Sleep spindles and K-complexes emerge in stage 2 sleep. Ⓒ 2020 About, Inc. (Dotdash) — All rights reservedWhat It's Like to Have an Electroencephalogram (EEG)Arousal is an Abrupt Change in the Pattern of Brain Wave ActivitySleep Hygiene Is a Composite of Factors that Impact Sleep QualityUnderstand Why You Wake up at the Same Time Every Single NightHow Paradoxical Is Used in Sleep Medicine and InsomniaA Dream Deferred? The five stages make one sleep cycle which usually repeat every 90 to 110 minutes. Stage 1 non-REM sleep marks the transition from wakefulness to sleep.
After stage 3 sleep, stage 2 sleep is repeated before entering REM sleep.
In contrast, non-REM (NREM) sleep is subdivided into four stages distinguished from each other and from wakefulness by characteristic patterns of brain waves. Alternatively, dreaming may represent a state of protoconsciousness, or a virtual reality, in the mind that helps a person during consciousness.1. It is important to realize that sleep does not progress through these stages in sequence.
It also acts as a transitional period between light sleep and a very deep sleep.
The brain waves associated with this stage of sleep are very similar to those observed when a person is awake, as shown in (a) A period of rapid eye movement is marked by the short red line segment. Recently, however, some have suggested that sleep deprivation might change emotional processing so that various stimuli are more likely to be perceived as positive in nature (Gujar, Yoo, Hu, & Walker, 2011).