In the 1999 motion picture The Matrix, the character of Neo experiences déjà vu (though the experience somewhat differs: Neo sees a black cat go past two times consecutively). Trinity explains to Neo that "the déjà vu is usually a glitch in the Matrix. It happens when they (Matrix agents) change something." Déjà vu is the name of a Giant Inverted Boomerang ("Super Invertigo") roller coaster by Vekoma that is operating at Six Flags Great America, Six ...

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Déjà vu, Déjà vu - Types of déjà vu, Déjà vu - Déjà vécu, Déjà vu - Déjà senti, Déjà vu - Déjà visité, Déjà vu - Scientific research, Déjà vu - Links with disorders, Déjà vu - Parapsychology, Déjà vu - Dreams, Déjà vu - Related phenomena, Déjà vu - Popular References, Déjà vu - References and notes

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Florid hallucinations are usually associated with drug use (particularly hallucinogenic drugs), sleep deprivation, psychosis or neurological illness. However, studies have shown that hallucinatory experiences take place across the population as a whole. Previous studies, one as early as 1894[1], have reported that approximately 10% of the population experience hallucinations. A recent survey of over 13,000 people^{See also:}

Hallucination, Hallucination - Origins of the word, Hallucination - Possible causes

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In recent years, déjà vu has been subjected to serious psychological and neurophysiological research. The most likely candidate for explanation, according to scientists in these fields, is that déjà vu is not an act of "precognition" or "prophecy" but is actually an anomaly of memory; it is the impression that an experience is "being recalled" which is false. This is substantiated to an extent by the fact that in most cases the sense of "recollection" at the time is strong, but any circumstances of the "previous" experience (when, where ...

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Déjà vu, Déjà vu - Scientific research, Déjà vu - Links with disorders, Déjà vu - Parapsychology, Déjà vu - Dreams, Déjà vu - Related phenomena, Déjà vu - Popular References

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Historically four major types of continuous rhythmic sinusoidal EEG waves are recognized (alpha, beta, delta and theta). There is no precise agreement on the frequency ranges for each type. Delta is the frequency range up to 4 Hz and is often associated with the very young and certain encephalopathies and underlying lesions. It is seen in deep sleep. Theta is the frequency range from 4 Hz to 8 Hz and is associated with drowsiness, childhood, adolescence and young adulthood. This EEG frequency can sometimes be ...

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Electroencephalography, Electroencephalography - Methods, Electroencephalography - Wave types, Electroencephalography - History, Electroencephalography - Notes

Read more here: » Electroencephalography: Encyclopedia II - Electroencephalography - Wave types

In recent years, déjà vu has been subjected to serious psychological and neurophysiological research. The most likely candidate for explanation, according to scientists in these fields, is that déjà vu is not an act of "precognition" or "prophecy" but is actually an anomaly of memory; it is the impression that an experience is "being recalled" which is false. This is substantiated to an extent by the fact that in most cases the sense of "recollection" at the time is strong, but any circumstances of the "previous" experience (when, where ...

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Déjà vu, Déjà vu - Types of déjà vu, Déjà vu - Déjà vécu, Déjà vu - Déjà senti, Déjà vu - Déjà visité, Déjà vu - Scientific research, Déjà vu - Links with disorders, Déjà vu - Parapsychology, Déjà vu - Dreams, Déjà vu - Related phenomena, Déjà vu - Popular References, Déjà vu - References and notes

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Narcolepsy may be associated with damage to the hypothalamus. A cerebral protein has recently been discovered that is decreased in a large number or all narcolepsy patients. The protein involved is called hypocretin or orexin. This might explain why narcolepsy runs in families. The neural control of normal sleep states and the relationship to narcolepsy are only partially understood. In humans, narcoleptic sleep is characterized by a tendency to go abruptly from a waking state to REM sleep with little or no intervening non-REM sleep. ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

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Diagnosis is relatively easy when all the symptoms of narcolepsy are present. But if the sleep attacks are isolated and cataplexy is mild or absent, diagnosis is more difficult. Two tests that are commonly used in diagnosing narcolepsy are the polysomnogram and the multiple sleep latency test. These tests are usually performed by a sleep specialist. The polysomnogram involves continuous recording of sleep brain waves and a number of nerve and muscle functions during nighttime sleep. When tested, people with narcolepsy fall asleep rapi ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

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Studies supported by the National Institutes of Health (NIH) are trying to increase understanding of what causes narcolepsy and improve physicians' ability to detect and treat the disease. Scientists are studying narcolepsy patients and families, looking for clues to the causes, course, and effective treatment of this sleep disorder. Recent discovery of families of dogs that are naturally afflicted with narcolepsy has been of great help in these studies. Some of the specific questions being addressed in NIH-supported studies are the n ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

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Learning as much about narcolepsy as possible and finding a support system can help patients and families deal with the practical and emotional effects of the disease, possible occupational limitations, and situations that might cause injury. A variety of educational and other materials are available from sleep medicine or narcolepsy organizations. Support groups exist to help persons with narcolepsy and their families. Individuals with narcolepsy, their families, friends, and potential employers should know that: ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

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Richard Caton (1842–1926), a physician practicing in Liverpool, presented his findings about electrical phenomena of the exposed cerebral hemispheres of rabbits and monkeys in 1875. In 1913, Russian physiologist, Vladimir Vladimirovich Pravdich-Neminsky published the first EEG and the evoked potential of the mammalian (dog)[1]. German physiologist Hans Berger (1873–1941) began his studies of the human EEG in 1920. He gave the device its name ...

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Electroencephalography, Electroencephalography - Methods, Electroencephalography - Wave types, Electroencephalography - History, Electroencephalography - Notes

Read more here: » Electroencephalography: Encyclopedia II - Electroencephalography - History

Many report hallucinations during episodes of sleep paralysis. The features of these hallucinations generally vary by individual, but some are more common to the experience than others: Most common Vividness Fear Common Sensing a "presence" (often malevolent) Pressure/weight on body (especially the chest). See for example the painting in the begining of this article, which is due to this phenomenon. A sensation of not bein ...

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Sleep paralysis, Sleep paralysis - Accompanying hallucinations, Sleep paralysis - Possible causes, Sleep paralysis - Cultural references, Sleep paralysis - Treatment in literature

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Sleep - Methodology. Before advances in the fields of neurology, neuroscience, electronics and genetics were made, scientists studied the behavioral characteristics of sleep, such as its pattern, depth and varying frequency. In more recent times, the electrical impulses generated by the brain are recorded using a device called an electroencephalograph (EEG), and individual genes relating to sleep-related brain function, such as the circadian rhythm, are isolated. Molecular biology, medical science and epidemiology all play an ...

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Sleep, Sleep - Sleep physiology, Sleep - Methodology, Sleep - Sleep regulation, Sleep - Stages of sleep, Sleep - Theories regarding the function of sleep, Sleep - Dreaming, Sleep - Sleep deprivation, Sleep - Sleep disorders, Sleep - Animal sleep, Sleep - Approaches to sleeping better, Sleep - Drugs and sleep, Sleep - Sleep aiding, Sleep - Stimulant drugs

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Psychosis is considered by mainstream psychiatry to be a symptom of severe mental illness, but not a diagnosis in itself. Although it is not exclusively linked to any particular psychological or physical state, it is particularly associated with schizophrenia, bipolar disorder (manic depression) and severe clinical depression. There are also several physical circumstances that can induce a psychotic state, including electrolyte disorder, urinary tract infections in the elderly, pain syndromes, drug toxicity, and drug withdrawal (especially a ...

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Psychosis, Psychosis - Overview, Psychosis - Psychotic experience, Psychosis - Hallucinations, Psychosis - Delusions and paranoia, Psychosis - Thought disorder, Psychosis - Lack of insight, Psychosis - Medical understanding of psychosis, Psychosis - Psychosis and brain function, Psychosis - Cannabis and psychosis, Psychosis - Non-psychiatric conditions and psychosis

Read more here: » Psychosis: Encyclopedia II - Psychosis - Overview

Sleep - Methodology. Before advances in the fields of neurology, neuroscience, electronics and genetics were made, scientists studied the behavioral characteristics of sleep, such as its pattern, depth, and varying frequency. In more recent times, the electrical impulses generated by the brain are recorded using a device called an electroencephalograph (EEG), and individual genes relating to sleep-related brain function, such as the circadian rhythm, have been isolated. Molecular biology, medical science and epidemiology all play an ...

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Sleep, Sleep - Sleep physiology, Sleep - Methodology, Sleep - Sleep regulation, Sleep - Stages of sleep, Sleep - Theories regarding the function of sleep, Sleep - Dreaming, Sleep - Sleep deprivation, Sleep - Sleep disorders, Sleep - Animal sleep, Sleep - Approaches to sleeping better, Sleep - Drugs and sleep, Sleep - Sleep aiding, Sleep - Stimulant drugs

Read more here: » Sleep: Encyclopedia II - Sleep - Sleep physiology

Khat has been grown for use as a drug for centuries in the Horn of Africa and the Arabian Peninsula. There, chewing khat predates the use of coffee and is used in a similar social context. Its fresh leaves and tops are chewed or, less frequently, dried and consumed as tea, in order to achieve a state of euphoria and stimulation. Due to the availability of rapid, inexpensive air transportation, the drug has been reported in London, Rome, Amsterdam, Canada, and the United States. The public has become more aware of this exotic drug through med ...

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Khat, Khat - Cultivation and uses, Khat - Chemistry/pharmacology, Khat - User population, Khat - USA, Khat - Israel, Khat - Control status

Read more here: » Khat: Encyclopedia II - Khat - Cultivation and uses

Several treatments are available for narcolepsy. These treat the symptoms, not the underlying cause. The drowsiness is normally treated using stimulants such as methylphenidate (Ritalin®), amphetamines (Adderall®), dextroamphetamine (Dexedrine®), methamphetamine (Desoxyn®), modafinil (Provigil®), etc. Other medications used are codeine and selegiline. In many cases, planned regular short naps can reduce the need for pharmacological treatment of the EDS to a low or non-existent level. The cataplexy is treated using clomipramine, impramin ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

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Normally, when an individual is awake, brain waves show a regular rhythm. When a person first falls asleep, the brain waves become slower and less regular. This sleep state is called non-rapid eye movement (NREM) sleep. After about an hour and a half of NREM sleep, the brain waves begin to show a more active pattern again, even though the person is in deep sleep. This sleep state, called rapid eye movement (REM) sleep, is when dreaming occurs. In narcolepsy, the order and length of NREM and REM sleep periods are disturbed, with REM sl ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

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In India, there are two thoughts. One of the signs of approaching enlightenment is "witnessing sleep," that is to say, being seemingly lucid in sleep — such as with sleep paralysis. It was also believed within the movement that rakshasas (Hindu demons) may assail those making strides towards their own enlightenment and the good of all mankind. The other thought is a female entity, called Mohini (a demoness from the underworld), comes into the night-time world by means of ascending through a deep well. She is enchantingly beautiful, yet sim ...

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Sleep paralysis, Sleep paralysis - Accompanying hallucinations, Sleep paralysis - Possible causes, Sleep paralysis - Cultural references, Sleep paralysis - Treatment in literature

Read more here: » Sleep paralysis: Encyclopedia II - Sleep paralysis - Cultural references

Disorders of sleep are broadly classified into three groups. Dyssomnias are characterized by difficulty getting to sleep, as in primary insomnia, narcolepsy, and restless legs syndrome. Obstructive sleep apnea, a condition that is being diagnosed with increased frequency, may be classified either as a dyssomnia or as an example of a parasomnia. The latter conditions involve bothersome awakenings during sleep, and also include bruxism and sleepwalking. The third group includes sleep disorders resulting from a number of psychiatric problems, such as bipola ...

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Sleep, Sleep - Sleep physiology, Sleep - Methodology, Sleep - Sleep regulation, Sleep - Stages of sleep, Sleep - Theories regarding the function of sleep, Sleep - Dreaming, Sleep - Sleep deprivation, Sleep - Sleep disorders, Sleep - Animal sleep, Sleep - Approaches to sleeping better, Sleep - Drugs and sleep, Sleep - Sleep aiding, Sleep - Stimulant drugs

Read more here: » Sleep: Encyclopedia II - Sleep - Sleep disorders

It is estimated that several million people are frequent users of khat. Many of the users originate from countries between Sudan and Madagascar and in the southwestern part of the Arabian Peninsula, especially Yemen. In Yemen, 60% of the males and 35% of the females were found to be khat users who had chewed daily for long periods of their life. The traditional form of khat chewing in Yemen involves only male users; khat chewing by females is less formal and less frequent. In Saudi Arabia, the cultivation and consumption of khat are forbidde ...

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Khat, Khat - Cultivation and uses, Khat - Chemistry/pharmacology, Khat - User population, Khat - USA, Khat - Israel, Khat - Control status

Read more here: » Khat: Encyclopedia II - Khat - User population

It is estimated that there are as many as 3 million people worldwide affected by narcolepsy. In the United States it is estimated that narcolepsy afflicts as many as 200,000 Americans, but fewer than 50,000 are diagnosed. It is as widespread as Parkinson's disease or multiple sclerosis and more prevalent than cystic fibrosis, but it is less well known. Narcolepsy is often mistaken for depression, epilepsy, or the side effects of medications. Narcolepsy can occur in both men and women at any age, although its symptoms are usually first ...

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Narcolepsy, Narcolepsy - Symptoms of narcolepsy, Narcolepsy - What happens in narcolepsy, Narcolepsy - Causes of narcolepsy, Narcolepsy - Prevalence of narcolepsy, Narcolepsy - Diagnosis, Narcolepsy - Treatment, Narcolepsy - Research, Narcolepsy - Coping with narcolepsy

Read more here: » Narcolepsy: Encyclopedia II - Narcolepsy - Prevalence of narcolepsy