0_Wizard
Sleep is differing from wakefulness by a lessor ability to react to stimuli
It is distinguished from wakefulness by a decreased ability to react to stimuli, but is more easily reversed than the state of being comatose.
chosen_Sleep_0
Sleep
chosen_topic_0_Sleep
Sleep and memory
The relationship between sleep and memory has been postulated and studied since at least the early 19th century. Memory, the cognitive process whereby experiences, learning and recognition are recalled, is a product of brain plasticity, the structural changes within synapses that create associations between stimuli. Stimuli are encoded within milliseconds; however, the long-term maintenance of memories can take additional minutes, days, or even years to fully consolidate and become a stable memory (more resistant to change or interference). Therefore, the formation of a specific memory occurs rapidly, but the evolution of a memory is often an ongoing process.
Neuroscience of sleep
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions. Traditionally, sleep has been studied as part of psychology and medicine. The study of sleep from a neuroscience perspective grew to prominence with advances in technology and proliferation of neuroscience research from the second half of the twentieth century. The fact that organisms daily spend hours of their time in sleep and that sleep deprivation can have disastrous effects ultimately leading to death, demonstrate the importance of sleep. For a phenomenon so important, the purposes and mechanisms of sleep are only partially understood, so much so that as recently as the late 1990s it was quipped: "The only known function of sleep is to cure sleepiness".
Sleep
Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, inhibition of nearly all voluntary muscles, and reduced interactions with surroundings. It is distinguished from wakefulness by a decreased ability to react to stimuli, but is more easily reversed than the state of being comatose. Sleep occurs in repeating periods, in which the body alternates between two distinct modes known as non-REM and REM sleep. Although REM stands for "rapid eye movement", this mode of sleep has many other aspects, including virtual paralysis of the body.
Sleep in non-human animals
Sleep in non-human animals refers to a behavioral and physiological state characterized by altered consciousness, reduced responsiveness to external stimuli, and homeostatic regulation. Sleep is observed in mammals, birds, reptiles, amphibians, and some fish, and, in some form, in insects and even in simpler animals such as nematodes. The internal circadian clock promotes sleep daily at night in diurnal organisms (such as humans) and in the day in nocturnal organisms (such as rodents). However, sleep patterns vary widely among species. Sleep appears to be a requirement for all mammals and most other animals.
Effects of sleep deprivation on cognitive performance
It has been estimated that over 20% of adults suffer from some form of sleep deprivation. Insomnia and sleep deprivation are common symptoms of depression and can be an indication of other mental disorders. The consequences of not getting enough sleep could have dire results; not only to the health of the individual, but those around them as sleep deprivation increases the risk of human-error related accidents, especially with vigilance-based tasks involving technology. The parietal lobes of the brain are largely involved in attention. Lesions to this region of the brain in humans result in difficulty or inability to attend to events that are contralateral to the lesioned hemisphere.
Rapid eye movement sleep
Rapid eye movement sleep (REM sleep, REMS) is a unique phase of sleep in mammals and birds, distinguishable by random/rapid movement of the eyes, accompanied with low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. The REM phase is also known as paradoxical sleep (PS) and sometimes desynchronized sleep because of physiological similarities to waking states, including rapid, low-voltage desynchronized brain waves. Electrical and chemical activity regulating this phase seems to originate in the brain stem and is characterized most notably by an abundance of the neurotransmitter acetylcholine, combined with a nearly complete absence of monoamine neurotransmitters histamine, serotonin, and norepinephrine.
Reticular formation
The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. The reticular formation is not anatomically well defined because it includes neurons located in diverse parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that stretches from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts of the descending reticular formation.
1_Apprentice
Oh cool! I always thought dreaming was the most interesting part of sleep.
0_Wizard
Sleep is a cycle of the body going from REM sleep to Non-REM sleep
Sleep occurs in repeating periods, in which the body alternates between two distinct modes known as non-REM and REM sleep.
chosen_Sleep_0
Sleep
chosen_topic_0_Sleep
Rapid eye movement sleep
Rapid eye movement sleep (REM sleep, REMS) is a unique phase of sleep in mammals and birds, distinguishable by random/rapid movement of the eyes, accompanied with low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. The REM phase is also known as paradoxical sleep (PS) and sometimes desynchronized sleep because of physiological similarities to waking states, including rapid, low-voltage desynchronized brain waves. Electrical and chemical activity regulating this phase seems to originate in the brain stem and is characterized most notably by an abundance of the neurotransmitter acetylcholine, combined with a nearly complete absence of monoamine neurotransmitters histamine, serotonin, and norepinephrine.
Neuroscience of sleep
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions. Traditionally, sleep has been studied as part of psychology and medicine. The study of sleep from a neuroscience perspective grew to prominence with advances in technology and proliferation of neuroscience research from the second half of the twentieth century. The fact that organisms daily spend hours of their time in sleep and that sleep deprivation can have disastrous effects ultimately leading to death, demonstrate the importance of sleep. For a phenomenon so important, the purposes and mechanisms of sleep are only partially understood, so much so that as recently as the late 1990s it was quipped: "The only known function of sleep is to cure sleepiness".
Sleep and memory
The relationship between sleep and memory has been postulated and studied since at least the early 19th century. Memory, the cognitive process whereby experiences, learning and recognition are recalled, is a product of brain plasticity, the structural changes within synapses that create associations between stimuli. Stimuli are encoded within milliseconds; however, the long-term maintenance of memories can take additional minutes, days, or even years to fully consolidate and become a stable memory (more resistant to change or interference). Therefore, the formation of a specific memory occurs rapidly, but the evolution of a memory is often an ongoing process.
Sleep in non-human animals
Sleep in non-human animals refers to a behavioral and physiological state characterized by altered consciousness, reduced responsiveness to external stimuli, and homeostatic regulation. Sleep is observed in mammals, birds, reptiles, amphibians, and some fish, and, in some form, in insects and even in simpler animals such as nematodes. The internal circadian clock promotes sleep daily at night in diurnal organisms (such as humans) and in the day in nocturnal organisms (such as rodents). However, sleep patterns vary widely among species. Sleep appears to be a requirement for all mammals and most other animals.
Sleep
Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, inhibition of nearly all voluntary muscles, and reduced interactions with surroundings. It is distinguished from wakefulness by a decreased ability to react to stimuli, but is more easily reversed than the state of being comatose. Sleep occurs in repeating periods, in which the body alternates between two distinct modes known as non-REM and REM sleep. Although REM stands for "rapid eye movement", this mode of sleep has many other aspects, including virtual paralysis of the body.
Activation-synthesis hypothesis
The activation-synthesis hypothesis, proposed by Harvard University psychiatrists John Allan Hobson and Robert McCarley, is a neurobiological theory of dreams first published in the American Journal of Psychiatry in December 1977. The differences in neuronal activity of the brainstem during waking and REM sleep were observed, and the hypothesis proposes that dreams result from brain activation during REM sleep. Since then, the hypothesis has undergone an evolution as technology and experimental equipment has become more precise. Currently, a three-dimensional model called AIM Model, described below, is used to determine the different states of the brain over the course of the day and night.
Dream
A dream is a succession of images, ideas, emotions, and sensations that usually occur involuntarily in the mind during certain stages of sleep. The content and purpose of dreams are not fully understood, though they have been a topic of scientific, philosophical and religious interest throughout recorded history. Dream interpretation is the attempt at drawing meaning from dreams and searching for an underlying message. The scientific study of dreams is called oneirology. Dreams mainly occur in the rapid-eye movement (REM) stage of sleep—when brain activity is high and resembles that of being awake.
1_Apprentice
Is there a certain amount of sleep required?
0_Wizard
During REM (Rapid Eye Movement) sleep the body is virtually paralyzed
Although REM stands for "rapid eye movement", this mode of sleep has many other aspects, including virtual paralysis of the body.
chosen_Sleep_0
Sleep
chosen_topic_0_Sleep
Rapid eye movement sleep
Rapid eye movement sleep (REM sleep, REMS) is a unique phase of sleep in mammals and birds, distinguishable by random/rapid movement of the eyes, accompanied with low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. The REM phase is also known as paradoxical sleep (PS) and sometimes desynchronized sleep because of physiological similarities to waking states, including rapid, low-voltage desynchronized brain waves. Electrical and chemical activity regulating this phase seems to originate in the brain stem and is characterized most notably by an abundance of the neurotransmitter acetylcholine, combined with a nearly complete absence of monoamine neurotransmitters histamine, serotonin, and norepinephrine.
Sleep and memory
The relationship between sleep and memory has been postulated and studied since at least the early 19th century. Memory, the cognitive process whereby experiences, learning and recognition are recalled, is a product of brain plasticity, the structural changes within synapses that create associations between stimuli. Stimuli are encoded within milliseconds; however, the long-term maintenance of memories can take additional minutes, days, or even years to fully consolidate and become a stable memory (more resistant to change or interference). Therefore, the formation of a specific memory occurs rapidly, but the evolution of a memory is often an ongoing process.
Neuroscience of sleep
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions. Traditionally, sleep has been studied as part of psychology and medicine. The study of sleep from a neuroscience perspective grew to prominence with advances in technology and proliferation of neuroscience research from the second half of the twentieth century. The fact that organisms daily spend hours of their time in sleep and that sleep deprivation can have disastrous effects ultimately leading to death, demonstrate the importance of sleep. For a phenomenon so important, the purposes and mechanisms of sleep are only partially understood, so much so that as recently as the late 1990s it was quipped: "The only known function of sleep is to cure sleepiness".
Non-rapid eye movement sleep
Non-rapid eye movement sleep (NREM) is, collectively, sleep stages 1–3, previously known as stages 1–4. Rapid eye movement sleep (REM) is not included. There are distinct electroencephalographic and other characteristics seen in each stage. Unlike REM sleep, there is usually little or no eye movement during these stages. Dreaming is rare during NREM sleep, and muscles are not paralyzed as in REM sleep. People who do not go through the sleeping stages properly get stuck in NREM sleep, and because muscles are not paralyzed a person may be able to sleepwalk. According to studies, the mental activity that takes place during NREM sleep is believed to be thought-like, whereas REM sleep includes hallucinatory and bizarre content.
Sleep
Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, relatively inhibited sensory activity, inhibition of nearly all voluntary muscles, and reduced interactions with surroundings. It is distinguished from wakefulness by a decreased ability to react to stimuli, but is more easily reversed than the state of being comatose. Sleep occurs in repeating periods, in which the body alternates between two distinct modes known as non-REM and REM sleep. Although REM stands for "rapid eye movement", this mode of sleep has many other aspects, including virtual paralysis of the body.
Narcolepsy
Narcolepsy is a long-term neurological disorder that involves a decreased ability to regulate sleep-wake cycles. Symptoms include periods of excessive daytime sleepiness that usually last from seconds to minutes and may occur at any time. About 70% of those affected also experience episodes of sudden loss of muscle strength, known as cataplexy. These experiences can be brought on by strong emotions. Less commonly there may be inability to move or vivid hallucinations while falling asleep or waking up. People with narcolepsy tend to sleep about the same number of hours per day as people without, but the quality of sleep tends to be worse.
Rapid eye movement sleep behavior disorder
Rapid eye movement sleep behavior disorder (RBD) is a sleep disorder (more specifically a parasomnia) that involves abnormal behavior during the sleep phase with rapid eye movement (REM) sleep. It was first described in 1986. The major and arguably only abnormal feature of RBD is loss of muscle atonia (i.e., the loss of paralysis) during otherwise intact REM sleep (during which paralysis is not only normal but necessary). REM sleep is the stage of sleep in which most vivid dreaming occurs. The loss of motor inhibition leads to a wide spectrum of behavioral release during sleep. This extends from simple limb twitches to more complex integrated movement, in which people appear to be unconsciously acting out their dreams.
1_Apprentice
That's interesting! What other cycles of sleep are there?