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Hallucination
A hallucination is a perception in the absence of an external stimulus that has the qualities of a real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. Hallucination is a combination of 2 conscious states of brain wakefulness and REM sleep. They are distinguishable from several related phenomena, such as dreaming ( REM sleep), which does not involve wakefulness; pseudohallucination, which does not mimic real perception, and is accurately perceived as unreal; illusion, which involves distorted or misinterpreted real perception; and mental imagery, which does not mimic real perception, and is under voluntary control. Hallucinations also differ from "delusional perceptions", in which a correctly sensed and interpreted stimulus (i.e., a real perception) is given some additional significance. Many hallucinations happen also during sleep paralyses. Hallucinations can occur in any sensory modality—visual, auditory, olfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Hallucination
An auditory hallucination, or paracusia, is a form of hallucination that involves perceiving sounds without auditory stimulus. While experiencing an auditory hallucination, the affected person would hear a sound or sounds which did not come from the natural environment. A common form of auditory hallucination involves hearing one or more voices without a speaker present, known as an ''auditory verbal hallucination''. This may be associated with psychotic disorders, most notably schizophrenia, and this phenomenon is often used to diagnose these conditions. However, individuals without any psychiatric disease whatsoever may hear voices, including those under the influence of mind-altering substances, such as cannabis, cocaine, amphetamines, and PCP. There are three main categories into which the hearing of talking voices often fall: a person hearing a voice speak one's thoughts, a person hearing one or more voices arguing, or a person hearing a voice narrating their own actions. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychosis
Psychosis is a condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavior that is inappropriate for a given situation. There may also be sleep problems, social withdrawal, lack of motivation, and difficulties carrying out daily activities. Psychosis can have serious adverse outcomes. As with many psychiatric phenomena, psychosis has several different causes. These include mental illness, such as schizophrenia or schizoaffective disorder, bipolar disorder, sensory deprivation and in rare cases, major depression (psychotic depression). Other causes include: trauma, sleep deprivation, some medical conditions, certain medications, and drugs such as cannabis, hallucinogens, and stimulants. One type, known as postpartum psychosis, can occur after giving birth. The neurotransmitter dopamine is believed to p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudohallucination
A pseudohallucination (from grc, ψευδής (pseudḗs) "false, lying" + "hallucination") is an involuntary sensory experience vivid enough to be regarded as a hallucination, but which is recognised by the person experiencing it as being subjective and unreal. By contrast, a "true" hallucination is perceived as entirely real by the person experiencing it. The term "pseudohallucination" appears to have been coined by Friedrich Wilhelm Hagen. Hagen published his 1868 book "Zur Theorie der Halluzination," to define them as "illusions or sensory errors". The term was further explored by the Russian psychiatrist Victor Kandinsky (1849–1889). In his work "On Pseudohallucinations" (russian: "О псевдогаллюцинациях" [o psevdogalliutsinatsiakh]), he described his psychotic experience defining pseudohallucinations as "subjective perceptions similar to hallucinations, with respect to its character and vividness, but that differ from those because these do not have objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdrawal, decreased emotional expression, and apathy. Symptoms typically develop gradually, begin during young adulthood, and in many cases never become resolved. There is no objective diagnostic test; diagnosis is based on observed behavior, a history that includes the person's reported experiences, and reports of others familiar with the person. To be diagnosed with schizophrenia, symptoms and functional impairment need to be present for six months (DSM-5) or one month (ICD-11). Many people with schizophrenia have other mental disorders, especially substance use disorders, depressive disorders, anxiety disorders, and obsessive–compulsive disorder. About 0.3% to 0.7% of people are diagnosed with schizophrenia during their lifetime. In 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Paralyses
Sleep paralysis is a state, during waking up or falling asleep, in which one is conscious but is completely paralyzed. During an episode, one may hallucinate (hear, feel, or see things that are not there), which often results in fear. Episodes generally last less than a couple of minutes. It can recur or occur as a single episode. The condition may occur in those who are otherwise healthy or those with narcolepsy, or it may run in families as a result of specific genetic changes. The condition can be triggered by sleep deprivation, psychological stress, or abnormal sleep cycles. The underlying mechanism is believed to involve a dysfunction in REM sleep. Lucid dreaming doesn't affect the chances of sleep paralysis but some lucid dreamers use this as a method of having a lucid dream. Diagnosis is based on a person's description. Other conditions that can present similarly include narcolepsy, atonic seizure, and hypokalemic periodic paralysis. Treatment options for sleep paral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypnopompia
Hypnopompia (also known as hypnopompic state) is the state of consciousness leading out of sleep, a term coined by the psychical researcher Frederic Myers. Its mirror is the hypnagogic state at sleep onset; though often conflated, the two states are not identical and have a different phenomenological character. Hypnopompic and hypnagogic hallucinations are frequently accompanied by sleep paralysis, which is a state wherein one is consciously aware of one's surroundings but unable to move or speak. Hallucinations Hallucinations are commonly understood as "sensory perceptions that occur in the absence of an objective stimulus". As this definition implies, though, like dreams, most hallucinations are visual, they can encompass a broader range of sensory experience. Auditory hallucinations are thus also common: "patients can hear simple sounds, structured melodies or complete sentences". Slightly less common but not unheard of are " somesthetic" hallucinations involving the sens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delirium Tremens
Delirium tremens (DTs) is a rapid onset of confusion usually caused by withdrawal from alcohol. When it occurs, it is often three days into the withdrawal symptoms and lasts for two to three days. Physical effects may include shaking, shivering, irregular heart rate, and sweating. People may also hallucinate. Occasionally, a very high body temperature or seizures (colloquially known as "rum fits") may result in death. Alcohol is one of the most dangerous drugs to withdraw from. Delirium tremens typically only occurs in people with a high intake of alcohol for more than a month. A similar syndrome may occur with benzodiazepine and barbiturate withdrawal. Withdrawal from stimulants such as cocaine do not have major medical complications. In a person with delirium tremens it is important to rule out other associated problems such as electrolyte abnormalities, pancreatitis, and alcoholic hepatitis. Prevention is by treating withdrawal symptoms. If delirium tremens occurs, ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypnagogic Hallucination
Hypnagogia is the experience of the transitional state from wakefulness to sleep: the ''hypnagogic'' state of consciousness, during the onset of sleep. Its opposite state is described as the transitional state from sleep into wakefulness. Mental phenomena that may occur during this "threshold consciousness" phase include hypnagogic hallucinations, lucid thought, exploding head syndrome, lucid dreaming, and sleep paralysis. The latter two phenomena are themselves separate sleep conditions that are sometimes experienced during the hypnagogic state. Definitions 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. However, ''hypnagogia'' is also regularly employed in a more general sense that covers both falling asleep and waking up. Indeed, it is not always possible in practice to assign a particular episode of any given phenomenon to one or the other, given that t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deliriant
Deliriants are a subclass of hallucinogen. The term was coined in the early 1980s to distinguish these drugs from psychedelics and dissociatives such as LSD and ketamine, respectively, due to their primary effect of causing delirium, as opposed to the more lucid and less disturbed states produced by other types of hallucinogens.Duncan, D. F., and Gold, R. S. (1982). Drugs and the Whole Person. New York: John Wiley & Sons The term generally refers to anticholinergic drugs, which are substances that inhibit the function of the neurotransmitter acetylcholine. Common examples of deliriants include plants of the genera ''Datura'' and ''Brugmansia'' (both containing scopolamine) as well as higher than recommended dosages of diphenhydramine (Benadryl). A number of plant deliriants such as that of the Solanaceae family, particularly in the Americas have been used by some indigenous cultures to reach delirious and altered states for traditions or rituals, such as rites of passage, divin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 – usually lasting one to two days. Chronic sleep deprivation means when an individual routinely sleeps less than an optimal amount for ideal functioning. Chronic sleep deficiency is often confused with the term insomnia. Although both chronic sleep deficiency and insomnia share decreased quantity and/or quality of sleep as well as impaired function, their difference lies in the ability to fall asleep. Sleep deprived individuals are able to fall asleep rapidly when allowed but those with insomnia have difficulty falling asleep. The average adult needs seven or more hours of sleep per night to mainta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
August Natterer
August Natterer (3 August 1868 – 7 October 1933), also known as Neter, was a German outsider artist with schizophrenia. Biography August Natterer, given the pseudonym ''Neter'' by his psychiatrist to protect him and his family from the intense social stigma associated with mental illness at the time, was born on 3 August 1868 in Schornreute near Ravensburg, Germany, the son of a clerk and the youngest of nine children. Natterer studied engineering, got married, travelled widely and had a successful career as an electrician, but was suddenly stricken with delusions and anxiety attacks. On 1 April 1907, he had a pivotal hallucination of the Last Judgment during which "10,000 images flashed by in half an hour". He described it as follows: This ordeal led to a suicide attempt and committal to the first of what would be several mental asylums occupied during the remaining twenty-six years of his life. Natterer thereafter maintained that he was the illegitimate child of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Eye Movement Sleep
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by 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 or dreamy 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. Experiences of REM sleep are not transferred to permanent memory due to absence of norepinephrine. REM sleep is physiologically different from the other phases of sleep, which are collectively referred to as non-REM sleep (NREM s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
