The Ganzfeld effect (from German for "complete field"), or perceptual deprivation, is a phenomenon of perception caused by exposure to an unstructured, uniform stimulation field. The effect is the result of the brain amplifying neural noise in order to look for the missing visual signals. [better source needed] The noise is interpreted in the higher visual cortex, and gives rise to hallucinations.
It has been most studied with vision by staring at an undifferentiated and uniform field of color. The visual effect is described as the loss of vision as the brain cuts off the unchanging signal from the eyes. The result is "seeing black", an apparent sense of blindness. A flickering ganzfeld causes geometrical patterns and colors to appear, and this is the working principle for mind machines and the dream machine.
Ganzfeld induction in multiple senses is called multi-modal ganzfeld. This is usually done by wearing ganzfeld goggles in addition to headphones with a uniform stimulus.
A related effect is sensory deprivation, although in this case a stimulus is minimized rather than unstructured. Hallucinations that appear under prolonged sensory deprivation are similar to elementary percepts caused by luminous ganzfeld, and include transient sensations of light flashes or colours. Hallucinations caused by sensory deprivation can, like ganzfeld-induced hallucinations, turn into complex scenes.
William G. Braud with Charles Honorton were the first to modify the ganzfeld procedure for parapsychological use. The effect is a component of the Ganzfeld experiment, a technique used in the field of parapsychology.
Oops something went wrong: