There are literally thousands upon thousands of books about magic—on its history, secrets, teachings, traditions, and rules—but to the extent of the authors’, and this reviewer’s, knowledge, Sleights of Mind: What the Neuroscience of Magic Reveals About Our Everyday Deceptions is the first book that addresses the cognitive science behind the trickery. Authors Stephen L. Macknik and Susana Martinez-Conde, a married couple, are both celebrated PhDs with the Barrow Neurological Institute, Macknik in behavioral neurophysiology and Martinez-Conde in visual neuroscience. Their collaborator, Ms. Blakeslee, is a regular science contributor to The New York Times and specializes in the brain sciences. Together, they have created a work that not only examines how magic can illuminate the inner workings of our brains’ perceptions of the world, but also uses a deeper understanding of cognition to explain how the illusions of magic are successful.
In the authors’ words, “neuromagic” is the “neuroscience of magic,” a term they created to describe the study of how magic is created within our cognitive perception. They came to this area of study in somewhat roundabout way. After coming up with the Best Illusion of the Year contest, now in its seventh year, they were asked to chair the Association for the Scientific Study of Consciousness annual conference in 2007. Because the conference was to be held in Las Vegas, they soon decided that the organizing theme would be to bring together the renowned magicians performing there with the scientist attendees. The outcome, of course, was a hit, and the authors proceeded to develop their research with the interrelation of science and magic as its driving force.
After the initial setup of what drew the authors to the world of magic, they proceed to explain how illusions are even possible:
“Magicians…exploit the fact that your brain does a staggering amount of outright confabulation in order to construct the mental simulation of reality known as ‘consciousness.’[…] The same neural machinery that interprets actual sensory inputs is also responsible for your dreams, delusions, and failings of memory.” (p. 9-10)
The illusions described and explained in the following chapters fall into three main categories: visual, cognitive, and choice/free will. Chapters 1-3 deal with how your eyes can trick your brain, most notably by interpreting a visual image incorrectly (e.g. perspective, light afterimages, etc.). The authors note that most visual illusions actually originated with painters having to overcome the obstacle of a 2-D medium to create scenes and images with depth and shadow. The Mona Lisa is the most famous example used—her expression, which has mystified many, is hard to pin down because the shadows on her mouth that lead us to deduce that she is smiling are only visible by not looking directly at her mouth. The result is a different expression depending on where your eyes are focused.
Chapters 4-8 deal with cognitive illusions, including those involving attention and memory. In fact, the authors point out, most visual illusions are based on cognitive tricks as well. It is the combination that has the most powerful effect on our perception. Attentional illusions center on the very simple method of getting the audience to direct their focus to one area of the stage or part of the magician, while the actual trick is happening in an entirely different place. Because the brain has a limited capacity for paying attention, inevitably a sort of “tunnel vision” results, making it possible for a lot to get by. In addition, the more you consciously decide to pay attention to an object, the less likely it is for you to notice anything outside of it.
Memory illusions are, in the authors’ opinion, the foundation of all great art: “Indeed, all great art is a violation of prediction” (p.142). With memory of a past event, e.g. the standard plot of a romantic comedy, comes the expectation and assumption of how a future event will happen. When our predictions are then “violated,” we are surprised and entertained, being that novelty sparks interest in our brains at a very primitive level. So when we remember seeing the queen of spades in the magician’s pocket, we assume that it will be there when he reaches for it a few minutes later. When it turns out that it’s a scarf in his pocket, and the queen of spades is now under his table, our neurons fire in satisfaction.
Finally, see Chapters 8 and 9 to realize how illusions involving choice and free will are among the most powerful in our analytic experience of magic. When you think you have freely chosen a card from a fanned deck or thought of a number between one and ten, it is all that much more affecting when the trick is ‘magically’ successful regardless of how hard you tried to ensure otherwise. Magicians have many techniques for ‘forcing’ a choice, and the authors explain the effect of this method by detailing how sensory input and attentional focus combine to make us absolutely sure that we are acting with free will when in fact we are simply being manipulated into feeling this way.
After experiencing and studying all of these illusions, the authors decide and start preparing to put on a show themselves, an audition for Magic Castle, the headquarters of the lauded Academy of Magical Arts. They bill themselves as the first neuroscientist magicians and attempt to use everything they found in their research—which apparently was successful, since they were accepted into the organization.
Their other definition of success in this endeavor is how the study of magic can further scientific goals:
“We propose that the study of magic is now poised to help to derive new principles to optimize attentional resources in people with cognitive decline, as well as to create heuristics to improve education in our schools.” (p. 249)
They have also planned further study on how magic can help evaluate and direct therapies for autism and other developmental disorders.