Basic Sleep Stages

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

The first example the author uses is a young adult name Randy Gardner. For a science project, he has deprived himself of sleep for 11 days in a row. A scientist named William Dement kept track of Randy’s brain function during the course of the experiment. Early on in the experiment, his symptoms included: forgetfulness, nausea and irritability. After sleep deprivation for five days he was experiencing paranoia, symptoms of Alzheimer’s and severe disorientation. During the last few days he was experiencing trembling fingers, slurred speech and a loss of motor function.

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).

This investigation examines is it possible for light pulses to alter the motor skills, and cardiac movements of biological life forms. Is it possible to change how biological lifeforms functions if we were to shine a light on them every hour at night? Knowing how most animals work, and from that of human experience I can say that light is what makes us stay awake; therefore if we have a light shined on us every hour would we lose sleep? These are the type of questions I will be answering throughout my extended essay. I will talk about how our sleep is affected by light, and monitor this so I can then record the data. I will also be discussing why we sleep. Which you may be wondering how this ties into light, however light does damage our skin

Out of the four main sleep theories, I believe cognitive development best relates to the events of today, and the medical procedure Joel received. I believe cognitive development relates well to the events of today because as said by G. William Domhoff (2014) “dreams dramatize our wishes, fears, concerns, and interest in striking scenarios that we experience as real events.” If you take a look at the categories of dream content Domhoff states, you realize most of your dreams you have had before fall into one or more of those categories. If you were to think back you could probably recall waking up after having a nightmare upset and with a racing heart. This is because dreams are so dramatically real like Domhoof states, and this explains why

During a night of sleep, we pass through 5 cycles, with 4 stages being non- rapid eye movement sleep (NREM) and the last being rapid-eye movement sleep (REM). The sleep cycle follows a pattern where it starts over every 90 minutes.1 When in stage one, you are in a very light state of sleep, and you can be very easily awakened. Eye movement just starts to slow down and muscles begin to relax.2 Then entering stage two, brain waves become slower and eye movement ceases, sometimes displaying spindles on the epochs.2 During this stage your heart rate and breathing remain the same, but your body starts to cool down as your temperature begins to decrease.1 Upon entering stages 3 and 4, you enter a deep sleep and it is hard to be awakened. In stage 3, your brain waves are very slow, or known as delta waves on the epoch.2 During these stages, you begin to breath slower, your blood pressure falls, and your muscles are fully relaxed. The last and final stage is known as REM sleep, and it occurs about every 90 minutes. You start to breathe faster, your eyes move very rapidly, heart rate goes up, and muscles are paralyzed.2 This is the stage where you dream.1

moment you begin to drift in and out of sleep and is considered to be the transition stage from wakefulness to sleep. The individual may be awakened easily and remains responsive to external stimuli. Heart rate, breathing and muscle activity slowly begin to decelerate. One’s blood pressure and body temperature slowly decreases and activity known as hypnic jerks, sudden muscle reflexive movements, often occur. These are thought of as vestigial reflexes of the evolutionary process and are accompanied by the feeling of falling or sinking.

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).

Each stage plays a different part in preparing you for the next day. There are two main types of sleep, Non-REM sleep and REM sleep. Non-REM sleep consists of three stages, each deeper than the last. These stages include transition to sleep being the first one, light sleep, and deep sleep being the last. REM sleep stands for rapid eye movement, in this sleep you do most active dreaming. The reason why it's called REM is because your eyes actually move back and forth during this

The sleep chapter was another eye-opening chapter for me. In this reflection I am going to summarize the states of sleep and what takes place during these stages.

stages, corresponding to increasing sleep depth . Stage 2 sleep corresponds to light sleep and is characterized by K complexes and sleep spindles. While sleep deepens, the amount of slow oscillations increases leading to stages 3 and 4 sleep, or slow wave sleep (SWS). In carnivores such as cats or dogs, NREM is subdivided into light and deep SWS; and in rats or mice only one NREM stage is usually defined. This categorization of sleep stages is however somehow arbitrary. All through the night, the NREM and REM sleep periods alternate following an ultradian cycle, SWS invariably preceding REM sleep in healthy subjects. In humans, the ultradian cycle is about 90±100 min, but it is important to note that SWS is most abundant during the first half of the night (up to 80% of the sleep time), while in the second half of the night, the proportion of REM

A typical night’s sleep is much more complicated than just closing your eyes and waking in the morning. As humans, we live our life on a circadian rhythm. This means that changes occur roughly based upon a 24-hour basis. This circadian rhythm plays a major role in when we get tired and decide it’s time to sleep. This rhythm is theorized to have helped us stay safe thousands of years ago. We would fall asleep during the time that their seemed to be threats roaming around in the dark. to Once we finally get to sleep, our brains and bodies are doing much more than laying in complete stillness. There are five distinct stages of sleep that we experience as we sleep. Each is uniquely different and serves a purpose throughout the night. The first stage of sleep is a very light sleep that lasts for 5 to 10 minutes. During this stage of sleep, you may not even realize that you’re sleeping. While in this stage of sleep our brains power down by 50 percent and produce theta waves four to seven times per second. We proceed to stage two after this. During stage two, our brains power down

In stage 3, extremely slow brain waves called ‘delta waves’ begin to appear, mixed in with smaller, faster waves. By stage 4, the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called deep sleep. There is no eye movement or muscle activity. People awakened during deep sleep do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up.

Brainwaves start to slow down. Stage 2: Eye movement stops and brain waves begin to become very slow. Stage 3 and 4: These are the stages where deep sleep begins. Also this is the most rejuvenating stage of sleep for the body. Stage 5: This stage is called R.E.M sleep, or rapid eye movement.

We spend about one-third of our life sleeping. As we get older, our bodies don’t need as much sleep, but it is still important that we get it. On average, young adults from the ages of 18-25 should be getting 7-9 hours of sleep a day. However, most of us don’t get that much. If we need less and less sleep as time goes on, then why is it important that we sleep at all? Although there are many scientists who have theories on why we need sleep, the three biggest theories on why are the Energy Conversion Theory, the Memory Consolidation Theory, and the Restore and Replenish Theory. All of these theories try to explain the importance of sleep, the biological function of sleep, and what can happen to the body if we aren’t getting the right amount.