Search results
Results from the WOW.Com Content Network
The purpose of alpha activity during REM sleep has yet to be fully understood. Currently, there are arguments that alpha patterns are a normal part of REM sleep, and for the notion that it indicates a semi-arousal period. It has been suggested that this alpha activity is inversely related to REM sleep pressure. [citation needed]
Sleep stages are characterized by spectral content of EEG: for instance, stage N1 refers to the transition of the brain from alpha waves (common in the awake state) to theta waves, whereas stage N3 (deep or slow-wave sleep) is characterized by the presence of delta waves. [107] The normal order of sleep stages is N1 → N2 → N3 → N2 → REM.
One of the important questions in sleep research is clearly defining the sleep state. This problem arises because sleep was traditionally defined as a state of consciousness and not as a physiological state, [14] [15] thus there was no clear definition of what minimum set of events constitute sleep and distinguish it from other states of partial or no consciousness.
Theta rhythm is prominent during part of awaking and REM sleep. Due to the density of its neural layers, the hippocampus generates some of the largest EEG signals of any brain structure. In some situations the EEG is dominated by regular waves at 4–10 Hz, often continuing for many seconds.
Brainwave entrainment, also referred to as brainwave synchronization or neural entrainment, refers to the observation that brainwaves (large-scale electrical oscillations in the brain) will naturally synchronize to the rhythm of periodic external stimuli, such as flickering lights, [1] speech, [2] music, [3] or tactile stimuli.
Known as slow-wave sleep or stage 3 non-REM sleep, this is the deepest stage of sleep and the hardest to wake up from. Brain activity slows down, muscles and bones strengthen, hormones regulate ...
Gamma oscillations have also been shown to correlate with the firing of single neurons, mostly inhibitory neurons, during all states of the wake-sleep cycle. [15] Gamma wave activity is most prominent during alert, attentive wakefulness. [13]
EEG showing brainwaves during REM sleep. In 1952, Eugene Aserinsky discovered REM sleep while working in the surgery of his PhD advisor. Aserinsky noticed that the sleepers' eyes fluttered beneath their closed eyelids, later using a polygraph machine to record their brain waves during these periods. In one session, he awakened a subject who was ...