Ganzfeld effect
Encyclopedia
The Ganzfeld effect is a phenomenon of visual perception
caused by staring at an undifferentiated and uniform field of color. The effect is described as the loss of vision as the brain cuts off the unchanging signal from the eyes. The result is "seeing black" - apparent blindness.
established that when subjects gazed into a featureless field of vision they consistently hallucinated
and their electroencephalograms changed.
The Ganzfeld effect is the result of the brain amplifying neural noise in order to look for the missing visual signals. The noise is interpreted in the higher visual cortex
, and gives rise to hallucinations. This is similar to dream production because of the brain's state of sensory deprivation
during sleep.
The Ganzfeld effect has been reported since ancient times. The adepts of Pythagoras
retreated to pitch black caves to receive wisdom through their visions, known as the prisoner's cinema
. Miners trapped by accidents in mines frequently reported hallucinations, visions and seeing ghosts when they were in the pitch dark for days. Arctic explorers seeing nothing but featureless landscape of white snow for a long time also reported hallucinations and an altered state of mind.
The effect is a component of a Ganzfeld experiment
, a technique used in the field of parapsychology
.
The artist James Turrell
(partly inspired by clear blue skies) has created many such "Ganzfelds" throughout his oeuvre.
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
caused by staring at an undifferentiated and uniform field of color. The effect is described as the loss of vision as the brain cuts off the unchanging signal from the eyes. The result is "seeing black" - apparent blindness.
History
In the 1930s, research by psychologist Wolfgang MetzgerWolfgang Metzger
Wolfgang Metzger is considered one of the main representatives of Gestalt psychology in Germany....
established that when subjects gazed into a featureless field of vision they consistently hallucinated
Hallucination
A hallucination, in the broadest sense of the word, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid,...
and their electroencephalograms changed.
The Ganzfeld effect is the result of the brain amplifying neural noise in order to look for the missing visual signals. The noise is interpreted in the higher visual cortex
Visual cortex
The visual cortex of the brain is the part of the cerebral cortex responsible for processing visual information. It is located in the occipital lobe, in the back of the brain....
, and gives rise to hallucinations. This is similar to dream production because of the brain's state of sensory deprivation
Sensory deprivation
Sensory deprivation or perceptual isolation is the deliberate reduction or removal of stimuli from one or more of the senses. Simple devices such as blindfolds or hoods and earmuffs can cut off sight and hearing respectively, while more complex devices can also cut off the sense of smell, touch,...
during sleep.
The Ganzfeld effect has been reported since ancient times. The adepts of Pythagoras
Pythagoras
Pythagoras of Samos was an Ionian Greek philosopher, mathematician, and founder of the religious movement called Pythagoreanism. Most of the information about Pythagoras was written down centuries after he lived, so very little reliable information is known about him...
retreated to pitch black caves to receive wisdom through their visions, known as the prisoner's cinema
Prisoner's cinema
The Prisoner's Cinema is a phenomenon reported by prisoners confined to dark cells and by others kept in darkness, voluntarily or not, for long periods of time. It has also been reported by truck drivers, pilots, and practitioners of intense meditation...
. Miners trapped by accidents in mines frequently reported hallucinations, visions and seeing ghosts when they were in the pitch dark for days. Arctic explorers seeing nothing but featureless landscape of white snow for a long time also reported hallucinations and an altered state of mind.
The effect is a component of a Ganzfeld experiment
Ganzfeld experiment
A ganzfeld experiment is a technique used in the field of parapsychology to test individuals for extrasensory perception . It uses homogeneous and unpatterned sensory stimulation to produce an effect similar to sensory deprivation. The deprivation of patterned sensory input is said to be conducive...
, a technique used in the field of parapsychology
Parapsychology
The term parapsychology was coined in or around 1889 by philosopher Max Dessoir, and originates from para meaning "alongside", and psychology. The term was adopted by J.B. Rhine in the 1930s as a replacement for the term psychical research...
.
The artist James Turrell
James Turrell
James Turrell is an American artist primarily concerned with light and space. Turrell was a MacArthur Fellow in 1984. He is represented by The Pace Gallery in New York...
(partly inspired by clear blue skies) has created many such "Ganzfelds" throughout his oeuvre.
See also
- Sensory deprivationSensory deprivationSensory deprivation or perceptual isolation is the deliberate reduction or removal of stimuli from one or more of the senses. Simple devices such as blindfolds or hoods and earmuffs can cut off sight and hearing respectively, while more complex devices can also cut off the sense of smell, touch,...
- Ganzfeld experimentGanzfeld experimentA ganzfeld experiment is a technique used in the field of parapsychology to test individuals for extrasensory perception . It uses homogeneous and unpatterned sensory stimulation to produce an effect similar to sensory deprivation. The deprivation of patterned sensory input is said to be conducive...
- Dark retreatDark retreatDark retreat refers to advanced practices in the Dzogchen lineages of the Nyingmapa, Bönpo and other schools of Tibetan Buddhism.The time period dedicated to dark retreat varies from a few hours to decades. Dark Retreat in the Himalayan tradition is a restricted practice only to be engaged by the...
- Floatation tank
- HypnagogiaHypnagogiaHypnagogia is the transitional state between wakefulness and sleep , originally coined in adjectival form as "hypnagogic" by Alfred Maury....