How do magicians play with our mind?
The Intentional blindness , or 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 carried out" is one of the strategies that magicians and illusionists have been practicing since Decades ago for our brain. This phenomenon, called in English Inattentional blindness is classified as an '' attention error '' and it has nothing to do with any visual deficit . In fact, it is a strategy of our mind to try to stop the stimulating overload to which we constantly expose ourselves.
However, this ruse is not the only one used by magicians to mislead us.
Among the studies conducted in the field of neuroscience, there is a very interesting article in which two researchers, Stephen L. Macknik and Susana Martínez Conde, proposed find the mechanisms that are produced so that our brain is unable to perceive the tricks that magicians use in their performances. For this, they had the collaboration of authentic professional magicians such as Penn and Teller (see article here).
Tricks and tricks most used by magicians
These authors explain that among the various tricks that illusionists use to deceive us are:
1) Optical illusions and other sensory ones, which are phenomena in which the subjective perception of an event does not agree with the physical reality of it.
A very plastic example that illustrates this is the trick of the buckets that bend. In this number, the magician bends the spoon so that its handle seems flexible.
The fact that we perceive this visual illusion is due to the fact that the neurons of the visual cortex sensitive, both to the movement and to the terminations of the lines, respond differently to the oscillations that other visual neurons . The result is an apparent discrepancy between the endings of a stimulus and its center; a solid object seems to flex in the middle. This '' neuronal desynchronization '' is what makes it seem like the spoon is bent.
Another variant of this trick is to use two spoons that are previously folded in a moment of distraction from the spectators. The magician holds them between the thumb and forefinger so that they are joined by the bent part of both. It seems that he is holding two unfolded spoons and crossed at the height of the neck of the handle. When you start to shake them, it gives the sensation that the spoons soften and bend around the neck. This optical phenomenon, also known as law of good continuity , makes us see the spoons as if they were crossed when the magician holds them, despite the fact that they are already folded.
2) Cognitive illusions such as blindness to change in which the viewer is not able to perceive that there is something different from what was before. The change can be expected or not, and can be sudden or gradual independent of interruptions.
Among the cognitive illusions is also the Inattentive or inattentive blindness, that we have already mentioned above.
Below are some videos that illustrate this fact:
Is the eye or the brain deceived?
A doubt that arises about how magicians get to trick us their tricks is if 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) they performed an experiment consisting in controlling the movements of the eyes of the spectators before a simple trick that consisted in 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 they did not see the trick. The conclusions of the study were that what the magician actually did was to manipulate the attention of the spectator more than his gaze, using the same principles that are used to produce the inatentional blindness.
How does our brain deal with the 'impossible'?
In a study conducted in 2006 by Kuhn and other cognitive neuroscientists, experimental subjects were asked to watch videos of magic tricks that seemed to exhibit impossible causal relationships, such as making a ball disappear. At the same time, functional magnetic resonance imaging of his brain was taken. A control group observed very similar videos, although not including magic tricks.
The results indicated increased activation in the anterior cingulate cortex among the subjects who were observing magic tricks that between the controls.
The discovery suggests that this brain area may be important for the interpretation of causal relationships.
This work by Kuhn and his colleagues only hints at the extent to which the attention of individuals and their ability to become aware of what is happening could be manipulated with magic techniques, in the meantime, to investigate the physiology of their brains
Bibliographic references:
- Kuhn, G. & Tatler, B. W. (2005). Magic and fixation: now you do not see it, now you do. Perception 34, 1155-1161
- Macknik, S.L., Martínez-Conde, S. (2013). The deceptions of the mind: How the magic tricks reveal the functioning of the brain. Barcelona: Destination.
- Stephen L. Macknik, Mac King, James Randi, Robbins Apollo, 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
