The inattentional blindness, or put another way, ”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 to trick our brain. This phenomenon, called in English Inattentional blindness It 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 tackle the stimulation 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 proposed find the mechanisms that occur so that our brain is unable to perceive the tricks that magicians use in their performances To do this, they had the collaboration of true professional magicians like Penn and Teller (see article here).
These authors state that among the various tricks that illusionists use to deceive us are:
1) Optical and other sensory illusions, which are phenomena in which the subjective perception of a fact does not agree with its physical reality.
A very plastic example that illustrates this is the bending spoons trick. In this number, the magician bends the spoon so that its handle appears flexible.
The fact that we perceive this visual illusion is due to the fact that neurons in the visual cortex sensitive to both movement and line endings respond differently to oscillations than other visual neurons The result is an apparent discrepancy between the endings of a stimulus and its center; a solid object appears to flex in the middle. This ”neural desynchronization” is what makes it seem like the spoon is bending.
Another variant of this trick consists of using two spoons that are previously bent at a time when the spectators are distracted. The magician holds them between his thumb and index finger so that they join together at the bent part of both. It appears that he is holding two spoons unbent and crossed at the neck level of the handle. As he begins to shake them, he gives the sensation that the spoons soften and bend at the neck. This optical phenomenon, also known as law of good continuity makes us see the spoons as crossing each other when the magician holds them, despite the fact that they are already bent.
2) Cognitive illusions such as change blindness in which the viewer is not able to perceive that there is something different from what there was before. The change may or may not be expected, and may be sudden or gradual regardless of whether there are interruptions.
Among the cognitive illusions there is also the inattentional or inattentional blindness, which we have already mentioned previously.
A question that arises about how magicians manage to sneak their tricks into our heads is whether it is because they distract our gaze from the moment in which they are performing the trick or, in reality, what they are manipulating is our attention. Kuhn and Tatler (2005) They carried out an experiment consisting of controlling the movements of the spectators’ eyes when faced with 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 they still didn’t see the trick. The conclusions of the study were that what the magician was actually doing was manipulating the spectator’s attention more than his gaze, using the same principles that are used to produce inattentional blindness
How does our brain tackle ‘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, fMRI images of his brain were taken. A control group watched very similar videos, although they did not include magic tricks.
The results indicated increased activation in the anterior cingulate cortex among the subjects who were observing magic tricks than among 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 suggests the extent to which the attention of individuals and their ability to become aware of what is happening could be manipulated with magical techniques, in order, in the meantime, to investigate the physiology of their brains.
