The Four Stages Of Sleep Research

Then you will move into stage two which includes sleep spindles and K complexes. Sleep spindles are very short bursts of brain activity, and K complexes are single high voltage strikes of brain activity. Also, in stage two delta brain waves start to slow function of the brain preparing for stage three and four. Stage three and stage four i will talk about as one because they are very similar and do similar things. These stages are referred to slow wave sleep because your brain is in it’s slowest speed of function. In stage three you brain is between 20 and 50 percent delta waves, from 50 to 100 percent delta waves you are considered to be in stage four. While in stage four people may experience sleep walking and other muscular movement without knowing so. Noises as loud as 90 decibels may not be able to wake the person from sleep. During REM sleep which is after NREM sleep the brain is more active and alert. This is where most dreams occur because your brain is active but you are still sleeping. After the short 15 minute period of REM sleep you will start over with stage one of NREM these cycles normally take 90 minutes to complete. Activity during sleep can come at any point but is most common in REM or stage four of

These stages are characterized by bursts of electrical activity on electroencephalogram (EEG) recordings. EEG readings monitor electrical activity representing neuronal activity in specific neurophysiological regions. Rapid eye movement (REM) sleep is characterized by desynchronized, saw-toothed theta rhythm waves and heightened cognitive activity. Comparatively, high amplitude, synchronous delta waves, and sharp hippocampal waves characterize slow wave sleep (SWS) sleep (stages 3-4 of non-REM sleep) (Tucker et al. 2006).

While awake, beta waves are active in the brain. The first stage is known as REM. This is where rapid eye movement occurs. As well, dreams typically occur here. As you begin to fall asleep these beta waves become less prevalent and theta waves start to develop. This occurs in the early stages of sleep. Furthermore, this stage is known as N1 which is a light sleep that usually occurs for about five minutes. During this time body temperature drops and shallow, irregular breathing occurs. The next stage is known as N2. An EEG would show sleep spindles at this point. As time goes on the brain will begin to produce delta waves. These waves are long and slow. They occur in the deepest stages of sleep known as N3. This stage is also responsible for growth hormones being released in the pituitary gland. After N3 the body will begin to wake up on its own. The body will return to it's REM stage where body temperature increases and eyes have movement.

During the first hour of sleep, brain waves slow down, and the eyes and muscles relax. Heart rate, temperate, and blood pressure fall as well. Over time, however, brain activity drastically increases from slow wave sleep to rapid eye movement (REM) sleep, and brain waves observed during REM are similar to those observed during waking. However, atonia occurs, which is when the body’s muscles are paralyzed, the muscles that allow breathing and control eye movements are fully active, and heart rate, blood pressure, and body temperature increase. As sleep continues, the brain alternates between periods of slow wave sleep. It’s divided into four stages. Stage 1, the brain activity is unsynchronized. Stage 2, our breathing, heartbeat, and brain activity become slower. Stage 3, our breathing, pulse, and brain activity is slower yet, and brain activity is synchronized. Stage 4 of sleep, our breathing, pulse, and brain activity is the slowest, and brain activity is highly synchronized. Brain activity is increased with each stage and brief periods of REM sleep, with the slow wave sleep becoming less deep and the REM periods more prolonged until you are woken. Approximately 20 percent of a person’s total sleep is spent in REM

Fifth Stage REM Rapid-Eye-Movement Sleep, while in REM breathing rates, brain activity increases and decreases, and brain waves are faster and smaller. Paradoxical sleep or active sleep refer to REM the reason for this is because brain, body become heightened and muscle movements are restrained but can twitch this is so dreams are not acted out. REM can last for up to fifteen min. From stage one NREM to REM sleep has taken about ninety min. For the rest of the night’s sleep cycle, it bounces between NREM and REM.

Stage 4 is known as rapid eye movement (REM) sleep. During this the respiration rate and

The brain activity during REM sleep is mainly mixed brain waves consisting of theta, alpha and beta waves. This is also the point in a sleep cycle where the body is basically rigid. The brain has shut off all muscle movements other than the ones that keep you alive. This stage is a prime example of how the brain is busy while we are sleeping, “REM sleep begins with signals from an area at the base of the brain called the pons. These signals travel to a brain region called the thalamus, which relays them to the cerebral cortex – the outer layer of the brain that is responsible for learning, thinking, and organizing information. The pons also sends signals that shut off neurons in the spinal cord, causing temporary paralysis of the limb muscles”(Brain Basics). Being that REM sleep deals with learning, scientists believe this is the reason infants sleep a large amount of time and also why they are more susceptible to being woken up by the slightest noises. Since this stage of sleeping has a great deal of dreaming and brain involvement some scientists believe that dreaming is the brain’s way of sorting out information it receives during sleep, creating a “story” out of what it gathers. REM sleep could be considered as a work out for your brain, helping us to make sense of what we experience throughout our

The stages of non-REM sleep, stages 1–3, are defined by EEG activity. Slow-wave sleep in stage 3 is the deepest stage of sleep. Alertness consists of desynchronized beta activity (13–30 Hz); relaxation and drowsiness consist of alpha activity (8–12 Hz); stage 1 sleep consists of alternating periods of alpha activity, irregular fast activity, and theta activity (3.5–7.5 Hz); the EEG of stage 2 sleep lacks alpha activity but contains sleep spindles (short periods of 12–14 Hz activity) and occasional K complexes; stage 3 sleep primarily consists of delta activity. About 90 minutes after the beginning of sleep, people enter REM sleep. Thereafter, cycles of REM and non-REM sleep occur in periods of approximately 90 minutes. Muscle tone decreases throughout the stages, resulting in deepest relaxation and paralysis in REM sleep (Carlson & Birkett, p. 268).

There are two distinct phases of human sleep. One phase is non-REM sleep, and the other is REM sleep. Non-REM sleep takes place in the first few hours of sleep at night, and REM sleep takes over the remaining hours allowing us to have dreams. Non-REM sleep is normally referred to as the resting state for our brain. Intense studies have discovered that the brain is less active during the phases of non-REM sleep compared to phases of being awake.

This stage is believed to help people enter deeper stages of sleep (4). Stage 3 sleep consists of 20-50 percent delta activity and stage 4 sleep of more than 50 percents delta activity (4). Stages 3 and 4 are characterized as being slow wave sleep in addition to being the deepest levels of sleep. Approximately 90 minutes after being asleep, people enter rapid-eye-movement (REM) sleep (4). REM sleep consists of rapid eye movements, a desynchronized EEG, sensitivity to external stimulation, muscle paralysis and dreaming (4).

In a normal night of an uninterrupted sleep, you cycle through these stages about four or five times each and it takes about 90 minutes to go through a complete cycle. But the order within a cycle tends to go from NREM-1 to NREM-2 to NREM-3 and then back to NREM-2 before entering REM sleep, and then back to NREM-1, and then it starts all over again.

A typical night's sleep cycle is four to ten hours.Typical sleep cycles include five stages of sleep. The first stage of sleep is W or wakefulness when someone is awake. The second stage is N1 or light sleep, this is the part of sleep that has theta waves. The third stage of sleep is N2 or sleep spindles, this is the stage where people drift further into sleep. The fourth stage of sleep is N3 or deep non-rapid eye movement, this stage is the deepest stage of sleep. The fifth stage of sleep is R or rapid

The first four stages are preparing the body for the last stage which is REM. These stages slow down the brain waves and stop the eye movement; stage four and three are known as delta sleep and during this stage the brain produces delta waves. Delta waves are the lowest out of the frequencies and occur during dreamless sleep. They are used to recover unavailable information that people cannot receive when they are awake. This leads to the REM cycle of sleep where all dreaming occurs. In the REM cycle the brain paralyzes our bodies so that people cannot move. When people first figured out what REM was they didn’t know that our bodies were paralyzed during the stage. The National Sleep Foundation has also been discovering more new things within this discovery. After the REM discovery, people recognized that brain activity during REM resembles wakefulness. People are paralyzed and experience no muscle movement(“National Sleep Foundation”). They have concluded that the REM stage indeed does put us through paralyzation during our sleep, but that's not the only thing our bodies do during REM. During the REM stage of sleep breathing become more irregular, more rapid, and shallow. Eyes jerk rapidly in various directions. Our blood pressure rises and heart rate increases. Our bodies are pretty much awake when we are in this stage(“What Are Dreams"). Usually someone wouldn’t expect this during sleep but this proves that our bodies are just as awake when sleeping than when they actually are awake. The brain and heart act the same way and so do our eyes (just not as slow moving). When someone is awoken during this stage they feel as if they had just experienced the dream in real life. They then realize that it was just a dream by remembering impossible things that couldn’t happen on earth. Because of this discovery of REM scientists can use this information to help figure out why we dream. Maybe they can

In stage one, a person is in a light sleep and can be awakened easily. The brain waves have a low amplitude and a fast frequency. In stage two, the waves have a low amplitude and "non-rhythmic brain activity." In stage two is a slight bit deeper sleep that stage one. Stage three, delta waves have a slower frequency and a high amplitude. Stage four is a person’s deepest state of sleep (Lefton, 196).

 There are five stages of sleep, REM and NREM stages 1, 2, 3, & 4.