Ganzfeld
healthline
What is the Ganzfeld Effect? Medically reviewed by Seunggu Han, M.D. — By Ann Pietrangelo on October 15, 2020
The ganzfeld experiment Uses How-to Side effects and precautions Summary
Illustration by Ruth Basagoitia
The ganzfeld effect happens when your brain is starved of visual stimulation and fills in the blanks on its own. This changes your perception and causes unusual visual and auditory patterns. It can even lead to hallucinations.
Psychologist Wolfgang Metzger introduced the concept of the ganzfeld effect in 1930. “Ganzfeld” is a German word that means “whole field.” It refers to an unstructured, uniform space covering your entire visual field.
Experiments on the ganzfeld effect have been used to investigate telepathy and hallucinatory states. Some people do it just for the experience.
Read on to learn more about the ganzfeld effect, whether it’s safe, and things to consider before attempting this experiment. How the ganzfeld effect works
If you can see, your brain uses visual input to make sense of the world. To create the ganzfeld effect, you have to deprive your brain of the information it needs to perform this task.
With no incoming signals, your perception of brightness slowly decreases. This is called the fade out.
As retinal cells become more active, you might start to see the blood vessels in your eyes. In a few minutes, things may turn gray. Then you might see zigzag lines, dots, or a blob of color. The full effect usually takes 5 to 7 minutes.
Longer exposure may produce stranger results. Your brain is frantically seeking outside stimuli. Finding none, the higher visual cortex starts amplifying available information, generating visual and auditory hallucinations.
It’s similar to what would happen if you were lost in a blinding snowstorm, seeing nothing but a wall of white. Practical uses of the ganzfeld effect
The ganzfeld effect came to public attention when it was used to research extrasensory perception.
In telepathy experiments, one person acts as the receiver and is exposed to white noise and a homogeneous red light. Another person, the sender, attempts to relay information to the receiver.
With mixed results, these investigations are controversial and have been fiercely debated.
The ganzfeld effect has also been used to research hallucinations. It has provided information on how our senses, especially vision, function to detect change.
Some people look at it as a way to induce visual phenomena and hallucinations without taking dangerous drugs. Some use it as a form of deep meditation.
For most people, it has no practical use, but it can help satisfy your curiosity about how the human mind functions. How to create the ganzfeld effect
To achieve the ganzfeld effect, you have to create that all-important uniform field of vision. This takes attention to detail.
One way to do this is to cut a Ping-Pong ball in half. You’ll use each half to cover a different eye. The balls should be clean, with no spots or writing. The halves should be tailored to your face so there are no gaps to let light in. You can use tape or adhesive to make sure they don’t move.
Another way is to cut plain white paper into the shape of an eye mask. Cut an elastic band and staple the ends of the band to each side of the mask. You’ll use this to keep the mask over your eyes. Glue cotton balls around the border of the mask to keep light from entering.
You can even buy ganzfeld goggles.
However you do it, light reaching your eyes must be equal in all directions. The room should have no shadows or flickering light. Some people choose to shine a bright light, usually red, to flood the room and keep the lighting uniform.
Then you’ll need noise-cancelling earphones, uninterrupted static, or some form of white noise.
Put the earphones and eye coverings on, but keep your eyes open. Then settle in, be still, and let the experiment begin.
Producing the ganzfeld effect is safe for most people. Potential side effects of ganzfeld hallucinations
While harmless for most, the experience can be disorienting and too intense for some people.
With exposure of 10 to 20 minutes, you may experience intermittent loss of vision. Some people can’t even tell if their eyes are open or closed. These effects can be unsettling, but they’re temporary.
It’s also possible to experience disturbing hallucinations. While this may actually be the goal for some people, hallucinations can be frightening. You shouldn’t try this experiment if you have a mental health condition that could be exacerbated by sensory deprivation or hallucinations. Takeaway
A ganzfeld is an unstructured, uniform space over your entire visual field. By altering your sense of sight and sound, you deprive your brain of the sensory input it needs to understand the outside world.
As your brain searches for information, it begins to fill in the missing pieces, which can produce visual and auditory hallucinations.
If you want to find out what your brain will conjure up, you can try to produce the ganzfeld effect on your own. It’s not harmful for most people.
Keep in mind that the experience is subjective. This means it’s different for everyone and may not live up to expectations.
Last medically reviewed on October 15, 2020 How we reviewed this article:
Share this article What Are Hallucinations and What Causes Them? Medically reviewed by Timothy J. Legg, PhD, PsyD — By Chitra Badii — Updated on July 11, 2019
Types Causes Diagnosis Treatment Outlook
Hallucinations are sensory experiences that appear real but are created by your mind. They can affect all five of your senses. For example, you might hear a voice that no one else can hear or see an image that isn’t real.
These symptoms may be caused by mental illnesses, the side effects of medications, or physical illnesses like epilepsy or alcohol use disorder.
You may need to visit a psychiatrist, a neurologist, or a general practitioner depending on the cause of your hallucinations.
Treatment may include taking medication to treat a health condition. Your doctor may also recommend adopting different behaviors like drinking less alcohol and getting more sleep to improve your hallucinations. Types of hallucinations
Hallucinations may affect your vision, sense of smell, taste, hearing, or bodily sensations. Visual hallucinations
Visual hallucinations involve seeing things that aren’t there. The hallucinations may be of objects, visual patterns, people, or lights.
For example, you might see a person who’s not in the room or flashing lights that no one else can see. Olfactory hallucinations
Olfactory hallucinations involve your sense of smell. You might smell an unpleasant odor when waking up in the middle of the night or feel that your body smells bad when it doesn’t.
This type of hallucination can also include scents you find enjoyable, like the smell of flowers. Gustatory hallucinations
Gustatory hallucinations are similar to olfactory hallucinations, but they involve your sense of taste instead of smell.
These tastes are often strange or unpleasant. Gustatory hallucinations (often with a metallic taste) are a relatively common symptom for people with epilepsy. Auditory hallucinations
Auditory hallucinations are among the most common type of hallucination. You might hear someone speaking to you or telling you to do certain things. The voice may be angry, neutral, or warm.
Other examples of this type of hallucination include hearing sounds, like someone walking in the attic or repeated clicking or tapping noises. Tactile hallucinations
Tactile hallucinations involve the feeling of touch or movement in your body. For example, you might feel that bugs are crawling on your skin or that your internal organs are moving around. You might also feel the imagined touch of someone’s hands on your body. What causes hallucinations? Mental health conditions
Mental illnesses are among the most common causes of hallucinations. Schizophrenia, dementia, and delirium are a few examples. Substance use
Substance use is another fairly common cause of hallucinations. Some people see or hear things that aren’t there after drinking too much alcohol or taking drugs like cocaine.
Hallucinogenic drugs like LSD and PCP can also cause you to hallucinate. Lack of sleep
Not getting enough sleep can also lead to hallucinations. You may be more prone to hallucinations if you haven’t slept in multiple days or don’t get enough sleep over long periods of time.
It’s also possible to experience hallucinations right before falling asleep, known as hypnagogic hallucinations, or right before waking up from sleep, known as hypnopompic hallucinations. Medications
Certain medications taken for mental and physical health conditions can also cause hallucinations. Parkinson’s disease, depression, psychosis, and epilepsy medications may sometimes trigger hallucination symptoms. Other conditions
Other conditions can also cause hallucinations. These can include:
high fevers, especially in children and the elderly migraine social isolation, particularly in older adults seizures deafness, blindness, or vision problems epilepsy (in some cases, epileptic seizures can cause you to see flashing shapes or bright spots) terminal illnesses, such as stage 3 HIV (AIDS), brain cancer, or kidney and liver failure
How are hallucinations diagnosed?
The best thing to do is call your doctor right away if you suspect that your perceptions aren’t real. Your doctor will ask about your symptoms and perform a physical exam. Additional tests might include a blood or urine test and perhaps a brain scan.
If you don’t already have a mental health professional, the Healthline FindCare tool can help you find a physician in your area.
If you know someone who’s hallucinating, don’t leave them alone. In some severe cases, fear and paranoia triggered by hallucinations can lead to dangerous actions or behaviors.
Stay with the person at all times and go with them to the doctor for emotional support. You may also be able to help answer questions about their symptoms and how often they occur.
If you need help finding a primary care doctor, then check out our FindCare tool here. How are hallucinations treated?
Your doctor will be able to recommend the best form of treatment for you once they figure out what’s causing your hallucinations. Medications
Treatment for your hallucinations will depend entirely on their underlying cause. For example, if you’re hallucinating due to severe alcohol withdrawal, your doctor might prescribe medication that helps calm down your nervous system.
However, if hallucinations are caused by Parkinson’s disease in a person with dementia, this same type of medication may not be beneficial, and other medications may be used.
An accurate diagnosis is very important for treating the condition effectively. Counseling
Counseling might also be part of your treatment plan. This is particularly true if the underlying cause of your hallucinations is a mental health condition.
Speaking with a counselor can help you get a better understanding of what’s happening to you. A counselor can also help you develop coping strategies, particularly for when you’re feeling scared or paranoid. What can I expect in the long term?
Recovery from hallucinations depends on the cause. If you’re not sleeping enough or you’re drinking too much, these behaviors can be adjusted.
If your condition is caused by a mental illness, like schizophrenia, taking the right medications can improve your hallucinations significantly. By seeing a doctor immediately and following a treatment plan, you’re more likely to have a positive long-term outcome.
