The Bizarre Sensory Phenomenon That Happens When Your Brain Gets Bored

The human brain handles a staggering amount of information every second. Everything you see, smell, feel, taste, or hear only makes sense because of specialized parts of the brain that manage sensory input. For example, specialized neurons in a brain region known as the visual cortex work with the eye, taking signals from the optic nerves and processing them to interpret things like color, depth, and motion. But if the brain doesn't get signals for too long, it essentially gets bored and starts filling in sensory gaps, causing unusual visual sensations, including hallucinations.

This phenomenon is known as the ganzfeld effect. The ganzfeld effect was first described in 1930 by a psychologist named Wolfgang Metzger. Ganzfeld is a German term meaning "whole field" that describes a uniform and structureless space that covers the entire field of vision.

Looking at an unchanging visual field means that the visual cortex isn't getting new information. After a short time without new signals, you'll start noticing that brightness is decreasing. This is known as fade out. Soon after that you might start seeing the blood vessels in your eyes and things might start looking gray. After about five to seven minutes you might see dots, blobs of colors, or lines. Longer exposure can cause some people to experience temporary loss of vision or hallucinations.

The unusual nature of the ganzfeld effect has attracted attention from people interested in how the brain operates. For example, people have used the ganzfeld effect to experience changes in perception without the use of mind-altering substances like drugs or hallucinogenic plants, or as a type of intense meditation. People often experience a state of consciousness that lies between being asleep and fully awake, during which time seems to pass more quickly.

These changes in perception have also been the subject of research on the brain and perception. Scientists have used the ganzfeld effect to learn about how human senses work to detect changes, as well as what happens during hallucinations. Additionally, the ganzfeld effect has attracted attention from those looking into whether psychic abilities like telepathy exist. In those experiments, one person is exposed to steady light and white noise to induce the ganzfeld effect while a sender tries to send information telepathically to the receiver. However, these kinds of experiments attempting to understand psychic powers failed to find conclusive evidence and have seen as controversial or pseudoscientific.

While the ganzfeld effect hasn't shown whether telepathy is possible, the experience itself shows how the brain depends on sensory input to function. It can be dramatic, but the effects are temporary and harmless in most people. However, people with mental health conditions like schizophrenia could have a more negative experience and as such should avoid experimenting with this effect.

For others, reaching this state of brain activity is relatively straightforward. All that's needed is to have a uniform field of vision. Some people use customized goggles that provide the necessary visual field while others use eye masks or ping pong balls cut in half and taped over each eye. Light should be uniform in all directions and there must be no shadows or highlights. People also often use noise canceling headphones or white noise generators to make sure the sound they hear is uniform as well.

While harmless for most people, the ganzfeld effect experience can be uncomfortable for some. Hallucinations can also be frightening, so while sensory deprivation in this way is safer than using consciousness-altering drugs, people should be mindful of what might happen before trying to induce the ganzfeld effect. Without sensory input, the brain starts getting bored, and the ways it tries to fill in the gap can be unpredictable.