How do magicians play with our minds?

This article explains the psychological tricks that magicians use to deceive us.

The inattentional blindnessor, in other words, ''the failure to detect an unexpected stimulus that is in our field of vision when other tasks that occupy our attention are being carried out'' is one of the strategies that magicians and illusionists have been practicing for decades to trick our brain. This phenomenon, called Inattentional blindness is classified as an ''attention error'' and has nothing to do with any has nothing to do with any visual deficit.. In fact, it is a strategy of our mind to try to cope with the stimulus overload to which we are constantly exposed.

However, this trick is not the only one used by magicians to mislead us.

Among the studies carried out in the field of neuroscience, there is a very interesting article in which two researchers, Stephen L. Macknik and Susana Martínez Conde set out to find the mechanisms that cause our brain to be unable to perceive the tricks used by magicians in their performances. to find the mechanisms that cause our brain to be unable to perceive the tricks used by magicians in their performances. To do so, they had the collaboration of real professional magicians such as Penn and Teller (see article here).

Tricks and gimmicks most used by magicians

These authors state that among the various tricks used by illusionists to deceive us are the following:

1) Optical illusions and others of sensory character, which are phenomena in which the subjective perception of a fact does not agree with the physical reality of the same.

A very plastic example that illustrates this is the trick of the spoons that bend. In this act, the magician makes the spoon bend in such a way that its handle appears flexible.

The fact that we perceive this visual illusion is because neurons in the visual cortex that are sensitive to both motion and line endings respond differently to oscillations than other visual neurons.. The result is an apparent discrepancy between the terminations of a stimulus and its center; a solid object appears to flex in the middle. This ''neuronal desynchronization'' is what makes the spoon appear to bend.

Another variation of this trick consists of using two spoons that are previously bent in a moment of distraction of the spectators. The magician holds them between thumb and forefinger so that they are joined at the bent part of both. He appears to be holding two unbent spoons crossed at the neck of the handle. As he begins to shake them, the spoons appear to soften and bend at the neck. This optical phenomenon, also known as law of good continuitycauses us to see the spoons as if they were crossed when the magician holds them, despite the fact that they are already bent.

2) Cognitive illusions such as change-blindness in which the spectator is not able to perceive that there is something different from what was there before. The change may be expected or unexpected, and may be sudden or gradual regardless of whether there are interruptions.

Cognitive illusions also include inattentional or inattentional blindness. inattentional or inattentional blindness, which we have already mentioned above.

Below are some videos illustrating this fact:

Is the eye or the brain being fooled?

One doubt that arises about how magicians manage to trick us with their tricks is whether it is because they distract our gaze from the moment in which they perform the trick or, in reality, what they manipulate is our attention. Kuhn and Tatler (2005) performed an experiment consisting of controlling the eye movements of the spectators before a simple trick that consisted of making a cigarette disappear (the magician threw it under the table) and what they saw was that the spectator was looking at the cigarette at all times but still did not see the trick. The conclusions of the study were that what the magician was actually doing was manipulating the spectator's attention rather than their gaze, using the same principles that are used to produce inattentional blindness.

How does our brain deal with 'the impossible'?

In a 2006 study by Kuhn and other cognitive neuroscientists, experimental subjects were asked to watch videos of magic tricks that appeared to exhibit impossible causal relationships, such as making a ball disappear. At the same time, functional magnetic resonance imaging was taken of their brains. A control group watched very similar videos, although without including magic tricks.

The results indicated greater activation in the anterior cingulate cortex among subjects among subjects who were watching magic tricks than among controls.

The finding suggests that this brain area may be important for the interpretation of causal relationships.

This work by Kuhn and colleagues only hints at the extent to which one could manipulate with the techniques of magic the attention of individuals and their ability to become aware of what is happening, to, in the meantime, investigate the physiology of their brains.

Bibliographical references:

• Kuhn, G. & Tatler, B. W. (2005). Magic and fixation: now you don't see it, now you do. Perception 34, 1155-1161

• Macknik, S. L., Martinez-Conde, S. (2013). Deceptions of the mind: How magic tricks unveil the workings of the brain. Barcelona: Destino.

• Stephen L. Macknik, Mac King, James Randi, Apollo Robbins, Teller, John Thompson, and Susana Martinez-Conde. (2008). Attention and awareness in stage magic: turning tricks into research. Nature Reviews Neuroscience. doi:10.1038/nrn2473