We were very sad to learn that Johnny Thompson (aka The Great Tomsoni) passed away on March 9, 2019, at the age of 84. We first met Johnny in 2007, when he spoke at the ‘Magic of Consciousness’ Symposium that we organized at the annual meeting of the Association for the Scientific Study of Consciousness, in Las Vegas. Johnny Thompson, along with Mac King, Teller, Apollo Robbins, and James Randi, talked to an academic audience of neuroscientists, psychologists and philosophers about his impressions about the psychologically puzzling aspects of magic, and helped jumpstart ‘neuromagic’ as a field of scientific enquiry. Johnny Thomson and his co-presenters inspired us, among many other investigators, to conduct research into the neuroscientific bases of magic. Dozens of papers by labs around the world have been published in the intervening decade as a result. Johnny himself co-authored an academic review with us, on the intersection of magic and neuroscience, published in Nature Reviews Neuroscience in 2008. Our later book Sleights of Mind: What the Neuroscience of Magic Reveals About Our Everyday Deceptions, drew significantly from our extensive conversations with Johnny and his keen insights.

Thompson was regarded as a deeply knowledgeable magician's magician and magic theorist. He was generous and kind with his wisdom and is widely recognized for having served as consultant to numerous world-renowned magic acts. Though his contributions to the neuroscience of magic are less well known than his magic artistry, they have led to significant advances in the science of attention and misdirection, too. Among the magic aphorisms we have heard over the years, one of our favorites is Johnny’s assertion that “when the audience laughs, time stops,” allowing the magician, at that precise moment, to get away with magical murder.

To remember Johnny Thompson, we excerpt here a description of one of Johnny's premiere tricks, the color changing dress trick.

Excerpt from our 2008 Scientific American article on ‘Magic and the Brain:’

The spotlight shines on the magician’s assistant. The woman in the tiny white dress is a luminous beacon of beauty radiating from the stage to the audience. The Great Tomsoni announces he will change her dress from white to red. On the edge of their seats, the spectators strain to focus on the woman, burning her image deep into their retinas. Tomsoni claps his hands, and the spotlight dims ever so briefly before reflaring in a blaze of red. The woman is awash in a flood of redness.

Whoa, just a moment there! Switching color with the spotlight is not exactly what the audience had in mind. The magician stands at the side of the stage, looking pleased at his little joke. Yes, he admits, it was a cheap trick; his favorite kind, he explains devilishly. But you have to agree, he did turn her dress red—along with the rest of her. Please, indulge him and direct your attention once more to his beautiful assistant as he switches the lights back on for the next trick. He claps his hands, and the lights dim again; then the stage explodes in a supernova of whiteness. But wait! Her dress really has turned red.

The Great Tomsoni has done it again!

The trick and its explanation by John Thompson (aka the Great Tomsoni) reveal a deep intuitive understanding of the neural processes taking place in the spectators’ brains—the kind of understanding that we neuroscientists can appropriate for our own scientific benefit. Here’s how the trick works. As Thompson introduces his assistant, her skintight white dress wordlessly lures the spectators into assuming that nothing—certainly not another dress—could possibly be hiding under the white one. That reasonable assumption, of course, is wrong. The attractive woman in her tight dress also helps to focus people’s attention right where Thompson wants it— on the woman’s body. The more they stare at her, the less they notice the hidden devices in the floor, and the better adapted their retinal neurons become to the brightness of the light and the color they perceive.

All during Thompson’s patter after his little “joke,” each spectator’s visual system is undergoing a brain process called neural adaptation. The responsiveness of a neural system to a constant stimulus (as measured by the firing rate of the relevant neurons) decreases with time. It is as if neurons actively ignore a constant stimulus to save their strength for signaling that a stimulus is changing. When the constant stimulus is turned off, the adapted neurons fire a “rebound” response known as an afterdischarge.

In this case, the adapting stimulus is the red-lit dress, and Thompson knows that the spectators’ retinal neurons will rebound for a fraction of a second after the lights are dimmed. The audience will continue to see a red afterimage in the shape of the woman. During that split second, a trap door in the stage opens briefly, and the white dress, held only lightly in place with Velcro and attached to invisible cables leading under the stage, is ripped from her body. Then the lights come back up.

Two other factors help to make the trick work. First, the lighting is so bright just before the dress comes off that when it dims, the spectators cannot see the rapid motions of the cables and the white dress as they disappear underneath the stage. The same temporary blindness can overtake you when you walk from a sunny street into a dimly lit shop. Second, Thompson performs the real trick only after the audience thinks it is already over. That gains him an important cognitive advantage—the spectators are not looking for a trick at the critical moment, and so they slightly relax their scrutiny.

Thompson’s trick nicely illustrates the essence of stage magic. Magicians are, first and foremost, artists of attention and awareness. They manipulate the focus and intensity of human attention, controlling, at any given instant, what we are aware of and what we are not. With those tools at their disposal, well-practiced magicians make it virtually impossible to follow the physics of what is actually happening—leaving the impression that the only explanation for the events is magic.

Additional Reading:

Susana Martinez-Conde and Stephen L. Macknik (2008). Magic and the Brain. Scientific American 299(6): 72-79.             

Stephen L. Macknik and Susana Martinez-Conde with Sandra Blakeslee (2010). “Sleights of Mind: What the Neuroscience of Magic Reveals about our Everyday Deceptions,” Henry Holt, New York City.              

Susana Martinez-Conde and Stephen L. Macknik (2007). Mind tricks. Nature 448: 414.   

Stephen L. Macknik et al. (2008). Attention and Awareness in Stage Magic: Turning Tricks Into Research. Nature Reviews Neuroscience 9(11): 871-879.