The Ganzfeld Effect: A Look Into Our Mind

The brain builds reality and is also in charge of interpreting it. It receives the electrical and chemical information sent by the senses. These environmental signals are generally variable and, in few circumstances, homogeneous. However, when these circumstances occur, a strange effect known as the Ganzfeld effect can occur.

Finding a stable pattern is not common, and even less if it does not have structure. Everything that we perceive in the world has a structure, has disturbances, variability, changes, produces different sensory stimulation and at different rates.

In addition, in nature change is the rule and the brain has adapted to it to build our perceptions, our world and form what remains in our memory as experience. But what would happen if we came across the exception: a stable, invariable, and unstructured condition? What effects would it have for us?

The Ganzfeld effect

In 1930, Wolfgang Metzger (researcher of Gestalt theory) introduced the concept of “Ganzfeld”. This term is made up of the German expression Ganz (translated as ‘integer, complete’) and Feld (translated as ‘field’), which together means ‘complete field’ or ‘entire field’.

This term refers to a uniform and unstructured space that stimulates the senses. It is also known as a “homogenized field”, because it is the same in all its points. Some examples are a clear blue monochromatic sky; the darkness of a room where nothing can be seen in different directions.

For these situations to be a Ganzfeld they must be homogeneous, not have contrasts with other types of stimuli. The same should be perceived in any direction or point. These conditions generally elicit perceptions in the absence of an objective structure. In other words, they favor or provoke hallucinations.

The studies carried out in this field have been, for the most part, done at the level of the sensory input of the ear and the eyes. Another phenomenon that is occasionally observed in these situations are episodes of “complete disappearance of the sense of vision for short periods of time”, also called “blackouts” (Wackermann, Pütz & Allefeld, 2008).

These blackouts are caused by habituation of sensory receptors and neurons. It is the reason why when we wear a watch for the first time we feel it instantly on our wrist, but then we stop perceiving it. Neural responses cease when stimulation is invariable and constant.

From all the above we can affirm then that the Ganzfeld effect is the set of perceptions that are experienced as a result of immersion in a homogenized, uniform or unstructured field.

How are the perceptions of the Ganzfeld effect?

These perceptions vary from person to person. Wackermann, Pütz, and Allefeld (2008) state that visual images of the Ganzfeld effect generally appear and disappear suddenly. Sometimes they appear as sudden and dynamic changes.

These authors collect some testimonials from people who have experienced this effect:

They have also recorded visual and auditory experiences, the product of homogeneous fields in both directions:

These complex hallucinations are not all affected by this effect. Some may perceive simple patterns, dots, or zigzag stripes. Others, as we have seen, may have more complex and structured perceptions. The effects are variable and different for each person.

How to generate this effect?

The core of the technique is exposing a person to homogeneous and unstructured sensory stimulation (Schmidt & Prein, 2019). It should be administered consistently and monotonously to avoid variability in sensory signals.

Visual techniques to generate the Ganzfeld effect

Several complex strategies have been created to reproduce at home, such as observing smooth walls on a large scale or translucent globes illuminated by diffuse light. Also, simpler ones have been proposed, such as cutting a ping-pong ball in half and using each part to cover each eye. To prevent them from falling off, they should be taped so that when you open your eyes, only the concavity of the halves can be seen.

Another way is to make glasses out of white paper. Care must be taken that it does not pass through any type of flash that could alter the uniformity of the white. Cotton can be used to cover any hole. Another alternative is to buy Ganzfeld glasses.

Auditory techniques to create the Ganzfeld effect

To achieve aural homogeneity, you can use white noise, such as tuned TV or radio sound, or pink noise. The important thing is that the sound is uniform.

The techniques, both visual and auditory, can be used together. It is even recommended to avoid distractions from the stimulation of the other senses. As far as possible, it should be done in a quiet place.

This type of experiment does not represent a danger to the integrity of those who carry it out. However, it is not recommended for those who have already had a problem of a psychotic nature, since the type of perception or hallucination they might have is not known.

Why do these hallucinations occur?

Visual hallucinations, a consequence of the Ganzfeld effect, can be the result of a neuronal amplification of the brain, in order to look for missing visual signals. This neural noise is interpreted by the superior visual cortex, producing hallucinations (Dunning and Woodrow, 2013).

In the same way, it is thought that the patterns that are observed, such as zigzag lines or dots, are the result of phenomena that occur in the retina. Receptor cells in the retina exhibit spontaneous activity, supersaturation, and inhibitory reactions. Prolonged exposure generates complex perceptions that involve the central nervous system (Zdravković, 2016).

The internal model

Reality, as we see it, hear it, smell it and feel it, does not come from outside, it comes from within. The brain builds its own reality before receiving information from the senses. This is known as the internal model.

Neuroscientist David Eagleman (2017) states that the foundation of this model can be observed in the anatomy of the brain. Almost all sensory information passes through the thalamus, on its way to the region of the brain responsible for processing these signals. Thus, there are many connections that go from the thalamus to the cortex, but those that go in the opposite direction (Cortex-Thalamus) are many more.

Our expectations of the world are transmitted from the brain to the thalamus. This structure compares what comes from the senses and compares it with expectations. The thalamus only reports on discrepancies between the signals from the senses and what the internal model has predicted.

” Instead of using the senses to reconstruct reality at every moment from scratch, you compare the sensory information with an internal model that the brain has already built: it updates it, refines it, corrects it ” (Eagleman, 2017, p.71 ). The above is proof that reality is not external, but internal. It does not depend on what is outside, but what is inside. The senses do not capture the world as we perceive it, it is the brain that builds everything.

This model allows us to propose another explanation for the hallucinations of the Ganzfeld effect, since it does not require much sensory information to perceive. When the brain does not receive signals other than those of the homogeneous field, it has no more new information to contrast and it gives free rein to its model of reality.

An effect that invites reflection

The Ganzfeld effect is one more example of the particular functioning of our brain. It defies common sense that tells us that everything we perceive exists that way in the outside world. It makes us perceive shapes, lines, points, colors and even situations that are only happening inside us.

This effect leaves the doors open to continue reflecting on reality. If what we perceive has no sustenance in the external world, is it real? If not, then what is the real thing? On the contrary, if we consider that these perceptions are real, what makes them so?