Susana Martínez-Conde:

Much of thework of a magiciandepends on your ability tochannel viewers’ attention. In fact, according to the CoruñaSusana Martínez-Conde, some of his tricks may provide clues to how ourbrainprocesses visual information and builds the subjective experience that we consider reality. To prove it, he has worked with some of theconjurersmost famous people in the world, such as Raymond Teller, Mac King, James Randi -a declared skeptic about everything that has to do with the paranormal- or Apollo Robbins, known for having turned the theft of purses into a true art. All of them are consummate masters in the use of optical, visual and also cognitive illusions, which are the ones that most interest this neurologist.

-What is the relationship between magic and science?
-I study themagicians tricksbecausemanipulate consciousness. Magicians are extraordinary manipulators and analyzing the illusions they use in their shows is, deep down, a way of investigating the inner workings of our brain. In fact, they have a lot to teach us about altering levels of attention. Based on their experiences, we can design more robust experiments in the laboratory that give us an idea of the behavior of the neural circuits involved in the construction of our own version of reality.

-However, magicians resort to different types of illusions. How are those that are exclusively optical different, for example, from those that are visual and so-called cognitive?
-Theoptical illusionsThey are the simplest, and to explain them it is not necessary to delve into the functioning of our brains. They can depend, for example, on the properties of light, such as refraction. Thus, if we put a pencil in a glass of water, it seems that it is broken. On the contrary, the visual ones – there are also auditory, tactile ones … – are related to neurons, in this case, of our visual system: a gray circle seems lighter to us if we surround it in black, and more dark if we surround it with white. This illusion, calledsimultaneous contrast, is based on how our brain perceives the reality outside. For him there are no absolute terms, it all depends on the context in which it is presented. Thecognitive, for their part, they also depend on neural circuits, but in this case the highest level network intervenes, that is, the one related to attention, memory, causal inference …

-So we can say that the cause-effect relationship is what produces that final surprise in magic …
-Sure; tricks generally seek to break the normal cause-effect relationship. The wand is essential for this. For example, if the magician touches a ball with it and it disappears, it gives us the feeling that the cause of the miracle is theWand, when in fact it is another mechanism. The true art of the magician is to make believe that there is a true correlation between the wand and the disappearance. And for this it has many resources.

-Humor is a common technique …
-That’s how it is. Not only is it a way to make the show more entertaining, but it is also used as a tool to redirect the audience’s attention. Johnny Thompson, one of our collaborating magicians, has told us that while people laugh it is as if time stopped. At that moment he could do whatever he wanted without anyone noticing.

-After studying magic from within, what effect does it have on you as a simple spectator?
-It must be professional deformation, but the point is that I am constantly trying to find out what is behind each trick. It is very difficult, because the staging is enormously effective. For example, magicians use thetension-relaxation effect. If the illusionist holds a coin in one hand and transfers it to the other, the one supposedly containing the object must appear to be strained. This dynamic of tension – where in reality there is no action – and of relaxation – where it does exist – is very common in disappearance tricks. Even if you try to focus on the relaxed hand, our attention ends up diverting to the part where we seem to perceive that there is action. Even knowing how to do it, it is something very sophisticated.

-And don’t we run the risk of taking some of the magic out of the magic?
-Thegreatest mystery of magic lies in our brain. So actually, it makes it more spectacular, because you really appreciate the skill of the artist. There we have Houdini. When someone performs that kind of metamorphosis that is magic at such a high level, the illusion continues to occur, no matter how much you know the trick or the neural circuits involved in the process.

-With all the research you carry behind your back, which representation is the one that continues to surprise you the most?
-Undoubtedly, that ofthe bullet of the duo Penn and Teller. In it, both shoot each other with pistols and each catches the projectile that the other has launched. The bullets with which the weapons are loaded have been previously signed by someone from the public and, furthermore, there appears to be no contact between the magicians’ hands. The result is that one fires and the other catches the bullet with his mouth! This is one of the best-executed tricks and they don’t reveal it just like that. In fact, there are magicians who have died trying to carry it out. The key is surely in our perception, but the fact is that you are deceived in the same way, whether you are an illusionist or an illusionist researcher.

-What is ruled out is that there are magicians with supernatural powers.
-What exist are magicians with abilities. They are carriers of one of the oldest known art forms. Some think that many of his techniques were already practiced in theAncient Egypt. The fact is that they developed a lot in theMiddle Ages, which attracted the attention of the Inquisition. The fear of being executed led some illusionists to explain how they performed their tricks, claiming that it did not take any influence from the Devil or other supernatural force to perform them.

-What will be the next step in your research in this field?
-Our next goal is to know how spectators and magicians themselves move their eyes during the show. For this, we have a special camera that is placed like a helmet. In our daily life we do not perceive exactly the things we look at. I mean, you may be looking at something, but you don’t really see it if you’re not paying attention. This occurs in a very marked way during magic tricks. There we have the case of Apollo Robbins, the pickpocket, who admits that he uses different hand gestures to guide the viewer’s attention. For example, if you want it to follow the path of your limb, you make a curved movement, but if you want it to perceive only the starting point and the end point of the action, you move it in a straight line. According to one hypothesis, the difference between the two stratagems is that in the curved movement the system of pursuit of the eyes is involved, while in the linear one, the one that participates is the so-called saccadic system. This produces very fast eye movements with which a target can be fixed in a minimum time.

-In other words, magicians have a superior capacity for visual perception
-There are always people with greater powers, but as a group I don’t think they have that supercapacity. What they do have is a lot of practice and training. I believe that anyone could become a magician, but not everyone is willing to put in the time and effort it takes.

-And what do you hope to achieve with these new studies?
-The idea is to discoverhow a normal brain builds vision. At the moment, we have a few principles that will allow us to develop diagnostic tools, especially from theeye movement. Its clinical applications include the treatment of attention disorders and the improvement of neurorehabilitation during some degenerative diseases. On the other hand, I would be especially interested in applying our findings in education. Knowing the keys to care would be a great tool for teachers. On a day-to-day basis, we choose at all times where we are going, so, in some way, it is the true beacon that guides us.

-It is, then, to find the key to visual consciousness …
-One of the great mysteries of neuroscience is the location of the neural bases of that consciousness, that is, what is the starting point of the subjective visual experience that we have of reality and that is not generated in the eyes. For example, you can close them and perfectly visualize a scene; people who have lost their sight keep dreaming in images … I don’t think it happens at the level of the primary visual cortex. In fact, you can exclude a series of areas in the brain that, although they process information, are not responsible for generating this conscious experience. For example, more than two dozen areas of the brain are dedicated tovisual processing. Of all of them, we know more or less how three work. It is clear that we still have a lot to investigate.

-But we cannot use the brain to try to understand the brain.
-There are those who say that due to this limitation we will never understand the functioning of this organ in a complete way. I am more optimistic: I do not believe that there is a real theoretical reason why we cannot reveal how the brain works and, incidentally, consciousness.

Isaac hernandez