High frequency and low amplitude.
Slow waves are a type of electrical activity that occurs within the brain during deep sleep. These waves are characterized by their slow frequency and high amplitude, and are believed to play a role in consolidating memories and promoting overall brain health. Monitoring slow waves can provide insights into the quality of sleep and brain function.
During deeper sleep stages, particularly stages 3 and 4 of non-REM sleep, brain activity slows down significantly, resulting in the predominance of delta waves, which are characterized by their high amplitude and low frequency. This phase is crucial for physical restoration, memory consolidation, and overall health. As sleep progresses, the duration of these deeper stages tends to decrease in favor of lighter sleep and REM sleep as the night continues. Disruptions in these deeper stages can lead to feelings of fatigue and impaired cognitive function upon waking.
Delta waves are associated with deep sleep. These brain waves have a frequency of 0.5 to 4 Hz and are characterized by their slow oscillations. They play a crucial role in restorative sleep, contributing to physical healing and growth, as well as memory consolidation. During deep sleep, delta waves dominate, indicating a state of reduced brain activity and increased relaxation.
The frequency of your brain waves during REM sleep are beta (which incidentally occurs during the waking state as well). These are low voltage, high frequency waves.
1. Stage One: lightest level of sleep; pulse slows, muscles relax, breathing uneven and brain waves irregular; awakened you'd report you were just drifting; lasts up to 10 minutes.Stage Two: brain waves shift from low amplitude, high frequency waves to high amplitude, low frequency waves; eyes roll from side to side; lasts 30 minutes.Stage Three: large amplitude waves sweep brain every second or so.Stage Four: deepest sleep, difficult to wake up from; regular delta waves occur more than 50% of time; talking out loud, sleepwalking, bedwetting can occur in this stage.REM sleep: a stage of sleep (past the fourth stage) characterized by rapid eye movement, a high level of brain activity, a deep relaxation of the muscles, and dreaming; face and fingers twitch; adrenal and sexual hormones rise in blood; large muscles are paralyzed; brain waves resemble a fully awake person; lasts 15 minutes (early at night) to 45 minutes (late at night); after this REM stage, a person regresses back into stage four; cycle repeats every 90 minutes or so.*(Stages One through Four are non-REM sleep which is quiet sleep)*
When awake, most people exhibit beta waves , the highest in frequency and lowest in amplitude, They are desynchronousthat is, the waves are not very consistent in their pattern. When relaxed most people exhibit alpha waves, which are slower, increase in amplitude and become more synchronous. The first stage of sleep is characterized by theta waves, which are even slower in frequency and greater in amplitude than alpha waves. Stages 1 and 2 are relatively "light" stages of sleep. A sleeper passes from the theta waves of stage 1 and 2, to the delta waves of stage 3 and 4. Delta waves are the slowest and highest amplitude brain waves. This is the deepest stage of the sleep cycle.The next stage is REM sleep, a sleepers brain waves demonstrate characteristics that are similar to waking sleep, a combination of alpha, beta, and desynchronous waves. This is the stage of sleep most associated with dreaming.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.
Brain waves change throughout the stages of sleep. During deep NREM sleep, slow-wave brain waves predominate. REM sleep is characterized by rapid and desynchronized brain waves similar to wakefulness. These changes in brain wave activity help regulate sleep cycles and promote essential functions like memory consolidation and restoration.
Delta Waves (APEX)
During slow-wave sleep, the brain activity of a person is characterized by synchronized, slow brain waves, while awake states are characterized by more desynchronized and faster brain waves associated with active cognitive processes. In slow-wave sleep, the brain shows reduced activity in regions responsible for higher cognitive functions like reasoning and decision-making, unlike during wakefulness when these regions are highly active.
The large, slow brain waves that are associated with deep sleep are called delta waves. They typically have a frequency of less than 4 Hz and are important for restorative sleep and bodily functions such as growth and immune responses.
alpha
Because during a REM stage your brain produces waves with a frequency and amplitude similar to beta waves. Beta waves have short frequencies and low amplitudes. These are the waves that are most common when you are most awake. Basically: you look asleep, but your brain is wide awake. REM sleep is when we remember our dreams, so it makes sense that our brains are most active when we are dreaming, seeing as that dreams require a lot of mental activity.