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.
Consciousness>Consciousness>States>Hallucination
1-Consciousness-States-Hallucination
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Date Modified: 2022.0224