Concept
Sleep paralysis
Related concepts (16)
Hypnagogia
Hypnagogia is the transitional state from wakefulness to sleep, also defined as the waning state of consciousness during the onset of sleep. Its opposite state is described as hypnopompia the transitional state from sleep into wakefulness. Mental phenomena that may occur during this "threshold consciousness" phase include hypnagogic hallucinations, lucid dreaming, and sleep paralysis. The word hypnagogia is sometimes used in a restricted sense to refer to the onset of sleep, and contrasted with hypnopompia, Frederic Myers's term for waking up.
Narcolepsy
Narcolepsy is a chronic neurological disorder that involves a decreased ability to regulate sleep–wake cycles. Symptoms often include periods of excessive daytime sleepiness and brief involuntary sleep episodes. About 70% of those affected also experience episodes of sudden loss of muscle strength, known as cataplexy. Narcolepsy paired with cataplexy is evidenced to be an autoimmune disorder. These experiences of cataplexy can be brought on by strong emotions.
Lucid dream
A lucid dream is a type of dream in which the dreamer becomes aware that they are dreaming while dreaming. During a lucid dream, the dreamer may gain some amount of control over the dream characters, narrative, or environment. Lucid dreaming has been studied and reported for many years. Prominent figures from ancient to modern times have been fascinated by lucid dreams and have sought ways to better understand their causes and purpose. Many different theories have emerged as a result of scientific research on the subject and have even been shown in pop culture.
Cataplexy
Cataplexy is a sudden and transient episode of muscle weakness accompanied by full conscious awareness, typically triggered by emotions such as laughing, crying, or terror. Cataplexy affects approximately 20% of people who have narcolepsy, and is caused by an autoimmune destruction of hypothalamic neurons that produce the neuropeptide hypocretin (also called orexin), which regulates arousal and has a role in stabilization of the transition between wake and sleep states. Cataplexy without narcolepsy is rare and the cause is unknown.
Night terror
Night terror, also called sleep terror, is a sleep disorder causing feelings of panic or dread and typically occurring during the first hours of stage 3–4 non-rapid eye movement (NREM) sleep and lasting for 1 to 10 minutes. It can last longer, especially in children. Sleep terror is classified in the category of NREM-related parasomnias in the International Classification of Sleep Disorders. There are two other categories: REM-related parasomnias and other parasomnias.
Nightmare
A nightmare, also known as a bad dream, is an unpleasant dream that can cause a strong emotional response from the mind, typically fear but also despair, anxiety, disgust or sadness. The dream may contain situations of discomfort, psychological or physical terror, or panic. After a nightmare, a person will often awaken in a state of distress and may be unable to return to sleep for a short period of time. Recurrent nightmares may require medical help, as they can interfere with sleeping patterns and cause insomnia.
Dream
A dream is a succession of s, ideas, emotions, and sensations that usually occur involuntarily in the mind during certain stages of sleep. Humans spend about two hours dreaming per night, and each dream lasts around 5 to 20 minutes, although the dreamer may perceive the dream as being much longer than this. The content and function of dreams have been topics of scientific, philosophical and religious interest throughout recorded history.
Mare (folklore)
A mare (mære, mare, ; mara in Old High German, Old Norse, and Swedish) is a malicious entity in Germanic and Slavic folklore that walks on people's chests while they sleep, bringing on nightmares. The word mare comes (through Middle English mare) from the Old English feminine noun mære (which had numerous variant forms, including mare, mere, and mær). These in turn come from Proto-Germanic *marōn. *Marōn is the source of mara, from which are derived mara; mara; marra; mare; mare/mara, Dutch: (nacht)merrie, and German: (Nacht)mahr.
Sleep deprivation
Sleep deprivation, also known as sleep insufficiency or sleeplessness, is the condition of not having adequate duration and/or quality of sleep to support decent alertness, performance, and health. It can be either chronic or acute and may vary widely in severity. Acute sleep deprivation is when an individual sleeps less than usual or does not sleep at all for a short period of time – normally lasting one to two days but tends to follow the sleepless pattern for longer with no outside factors in play.
Out-of-body experience
An out-of-body experience (OBE or sometimes OOBE) is a phenomenon in which a person perceives the world from a location outside their physical body. An OBE is a form of autoscopy (literally "seeing self"), although this term is more commonly used to refer to the pathological condition of seeing a second self, or doppelgänger. The term out-of-body experience was introduced in 1943 by G. N. M. Tyrrell in his book Apparitions, and was adopted by researchers such as Celia Green, and Robert Monroe, as an alternative to belief-centric labels such as "astral projection" or "spirit walking".