The Ganzfeld effect (from German for “complete field”) 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.
In the 1930s, research by psychologist Wolfgang Metzger 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.
- ^ Ramesh B. Ganzfeld Effect.
- ^ Ustinova, Yulia.Caves and the Ancient Greek Mind: Descending Underground in the Search for Ultimate Truth, Oxford University Press US, 2009. ISBN 0199548560
- Wolfgang Metzger, "Optische Untersuchungen am Ganzfeld." Psychologische Forschung 13 (1930) : 6-29. (the first psychophysiological study with regard to Ganzfelds)
EGG: Did you reach this conclusion through more traditional media, like painting or sculpture?
JT: I haven't had anything to do with either sculpture or painting. I have done works that look painted or works that have form and look like sculpture. I make these spaces that apprehend light for your perception. In a way, it's like Plato's cave, where we are sitting in the cave looking at the reflection of reality with our backs to reality. I make these spaces where the spaces themselves are perceivers or in some way pre-form perception. It's a little bit like what the eye does. I mean, I look at the eye as the most exposed part of the brain, as something that is already forming perception. I make these rooms that are these camera-like spaces that in some way form light, apprehend it to be something that's physically present.
EGG: What happens when you use space this way?
JT: This results in an art that is not about my seeing, it's about your direct perception of the work. I'm interested in having a light that inhabits space, so that you feel light to be physically present. I mean, light is a substance that is, in fact, a thing, but we don't attribute thing-ness to it. We use light to illuminate other things, something we read, sculpture, paintings. And it gladly does this. But the most interesting thing to find is that light is aware that we are looking at it, so that it behaves differently when we are watching it and when we're not, which imbues it with consciousness. Often people say that they want to touch some of the work I do. Well, that feeling is actually coming from the fact that the eyes are touching, the eyes are feeling. And this happens because the eyes are quite sensitive only in low light, for which we were made. We're actually made for this light of Plato's cave, the light of twilight. See: Interview with James Turrell
Dr. Raymond Moody, author of the 1981 book about near death experiences, Life After Life, included the psychomanteum in his research trialling 300 subjects which he recorded in his 1993 book, Reunions. Moody viewed the room as a therapeutic tool to heal grief and bring insight.