People can have sense perception in the absence of, or unrelated to, external stimuli {hallucination, state} [Ffytche et al., 1998] [Frith, 1996] [Green and McCreery, 1975] [Manford and Andermann, 1998] [Vogeley, 1999]. In hallucinations, red can seem blue, high voice can sound low, sweet can seem sour, and pain can be pleasurable.
Visual hallucinations are most common and typically show real persons. People see hallucinations as objects in space but know them to be false perceptions. Colors are typically reds, oranges, and yellows [Siegel and Jarvik, 1975] [Siegel and West, 1975] [Siegel, 1977] [Siegel, 1992]. Motions in hallucinations are often rotations or radial motions [Siegel and Jarvik, 1975] [Siegel and West, 1975] [Siegel, 1977] [Siegel, 1992]. Spirals and wiggly lines, circles, concentric figures or tunnels, webs, repeated lines, and intense colors are common in hallucinations [Bressloff et al., 2002] [Cowan, 1982] [Klüver, 1926]. People can have sound hallucinations [Gurney et al., 1886] [Sidgwick et al., 1894] [West, 1948].
behavior
People are passive during hallucination and feel that they have no control over recurring images and obsessions. The "I" or self persists through hallucinations.
perception
Other information cannot correct hallucinations. People cannot distinguish hallucination from perception {argument from illusion, hallucination}, except later by comparison and memory. Perception, dream, and hallucination experiences and sense qualities are similar.
causes
High arousal, low vigilance, perception impairment, reality-testing impairment and reduction, high expectation, long wakefulness or busyness, sickness, starvation, sensory deprivation, prolonged low stimulation, sleep deprivation, and rituals with rhythmic movements or sounds cause hallucinations.
Dreaming has visual hallucinations, such as hypnagogic hallucination and hypnopompic hallucination. Hypnosis can provoke hallucinations. Prolonged isolation causes anxiety and hallucinations. People with autistic thinking have hallucinations. People with paranoia have hallucinations. People with schizophrenia have hallucinations, typically voices talking to or about them.
Perhaps, memory release or imagination inhibition, when normal sensory data flow stops or changes, causes hallucinations [Jackson, 1887].
Launey-Slade Hallucination Scale indicates if people are susceptible to hallucinations.
causes: biology
Temporal-lobe stimulation can cause hallucinations. Anti-opiate drugs and phenothiazines cause hallucinations.
Epileptics can have autoscopy. People with migraine headaches can have autoscopy. Females have more hallucinations.
comparisons
Illusions are perceptions that look different than actual metric measurements. Illusions and hallucinations have similar sense qualities.
Imagery is distinguishable from hallucination. Imagery is under voluntary control, while hallucination is not. Hallucinations are about unreal or idiosyncratic objects or events, while imagery is about physical and cultural reality [Frith, 1995] [Slade and Bentall, 1988].
Near-death experiences are similar to autoscopic hallucinations.
People can see their clear, monochromatic, transparent, life-sized, and moving mirror image {doppelganger} {autoscopy}|. People typically see face, head, and/or trunk at one meter for several seconds. Social factors can determine forms that ghosts take. Images copy postures, facial expressions, and movements. Autoscopy lasts several seconds. Autoscopy occurs mostly at late night or dawn.
Autoscopy can happen during stress, fatigue, or disturbed consciousness. Delirious patients with parieto-occipital lesions, people with migraine attacks, and epileptics can have autoscopy.
People who become blind can hallucinate {Charles Bonnet syndrome} [Ffytche, 2000] [Ffytche and Howard, 1999] [Ramachandran and Blakeslee, 1998].
Out-of-body experience can involve seeing one's own body {heautoscopic experience}.
People can have visions when in danger, in hospital, or during attempted suicide {deathbed visions} {near-death experience}| (NDE). Near-death experiences can have tunnels or entry into darkness, out-of-body experiences, bright lights or emergence into light, peaceful and loving feelings, strange worlds, life-history memories, and choices to go back to the living world [Moody, 1975] [Morse, 1990] [Morse, 1993] [Parnia and Fenwick, 2002] [Parnia et al., 2001].
There can be peaceful feelings, out-of-body experiences, entries into darkness, visions of light, and emergences into light {Greyson NDE scale} [Ring, 1980].
Experiences can be regressions to childhood states. Mind feels love, peace, acceptance, and pureness, with focused attention, no criticism, and no available alternatives. Most near-death experiences are pleasant, but some are like hell [Parnia et al., 2001] [van Lommel et al., 2001].
stages
People first hear noises or move fast down tunnels or valleys. Then they feel that they are outside body but in same physical environment. Loneliness and timelessness feelings follow, with low emotions. People are invisible to others and cannot communicate. People feel no weight or other sense qualities. People feel peace, calm, joy, and love. People can know others' thoughts. Then friends or relatives that have died already come as spiritual helpers. Among them is a being of light, with personality. This being asks mental questions about readiness for death. Then people see a fast, accurate summary of their life from childhood to present. Then a barrier or border, a no-return line, approaches. However, people feel that they should go back and live, because it is not yet time, they have not yet done something, or people are calling them back. Then, preceded by unconsciousness, return to physical body is through head. Afterward, people feel that they must try to learn and love, with no fear of death or judgment and no worries about heaven or hell.
causes
Perhaps, unusual brain states cause near-death experiences {dying brain hypothesis}, as anoxia, stress, and fear activate brain [Blackmore, 1993].
Brain is often clinically dead or damaged {brain dead}, but experience can have happened before that [van Lommel et al., 2001].
No drugs cause near-death experiences [Parnia et al., 2001] [van Lommel et al., 2001].
comparisons
Near-death experiences are similar to high brain carbon-dioxide levels. Near-death experiences are similar to well-being feelings caused by brain endorphins. Near-death experiences are similar to autoscopic hallucinations. Near-death experiences are similar to LSD experiences. Near-death experiences are similar to sensory isolation experiences. Near-death experiences have no typical physiological symptoms [Parnia et al., 2001] [van Lommel et al., 2001].
Hallucinating people can see world from locations outside physical body {out-of-the-body experience} {out-of-body experience}| (OBE). One-fifth to one-quarter of people have at least one OBE during their lifetimes, often as children. Out-of-body experiences typically last from seconds to minutes [Blackmore, 1992] [Green, 1968]. Out-of-body experience can involve heautoscopic experience. Imagined-world model or representation replaces normal perceptual model. From above, people see imagined models. Models project what people see from another viewpoint. People feel that they perceive from positions different from head position [Alvarado, 1982] [Alvarado, 1992] [Blanke et al., 2002] [Grüsser and Landis, 1991] [Morris et al., 1978] [Penfield, 1955] [Penfield, 1958] [Tart, 1968].
If original body stays behind, people feel that they are in body or have no body [Green, 1968].
The experience feels like real life, not like dreams, and is often life-changing [Gabbard and Twemlow, 1984].
causes
Muscular relaxation, exhaustion, monotonous sounds, and certain drugs can disrupt both sense input and body image to make OBE. Out-of-body experiences typically happen when people relax and voluntary muscles are not moving, so internal stimulation is low. Body image lessens, as in drowsiness [Blackmore, 1992] [Green, 1968]. OBE can happen when outside stimulation is low.
People can have out-of-body experiences in depersonalization reactions.
Drugs that relax body and reduce body image can induce out-of-body experiences [Morse, 1990] [Persinger, 1983] [Persinger, 1999] [Shermer, 2000].
Near-death experiences often involve out-of-body experience.
Perhaps, out-of-body experiences involve temporal lobe [Morse, 1990] [Persinger, 1983] [Persinger, 1999] [Shermer, 2000].
comparisons
OBE relates to hypnotizability [Blackmore, 1996] [Gackenbach and LaBerge, 1988] [Irwin, 1985].
OBE relates to imagination, absorption, and belief in psi [Blackmore, 1996] [Gackenbach and LaBerge, 1988] [Irwin, 1985].
More lucid dreaming correlates with more out-of-body experiences [Blackmore, 1996] [Gackenbach and LaBerge, 1988] [Irwin, 1985].
Out-of-body experience is like vivid dreaming. OBEs are like dreams that people know are dreams. Out-of-body experiences are similar to stage one dreaming.
factors
OBE has no relation to age, education, gender, mental health, or religion.
Hallucinations {pseudohallucination} can be as vivid and immediate as perceptions, but people do not realize they are false. Pseudohallucinations are subjective responses to isolation or intense emotional need.
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Date Modified: 2022.0225