“Why does everything you know, and everything you’ve learned, confirm you in what you believed before? Whereas in my case, what I grew up with, and what I thought I believed, is chipped away a little and a little, a fragment then a piece and then a piece more. With every month that passes, the corners are knocked off the certainties of this world: and the next world too. Show me where it says, in the Bible, ‘Purgatory.’ Show me where it says ‘relics, monks, nuns.’ Show me where it says ‘Pope.’” –Thomas Cromwell imagines asking Thomas More—Wolf Hall by Hilary Mantel
Tuesday, December 14, 2010
Magic, Fiction, and the Illusion of Free Will part 1 of 2
Neuroscientist Stephen L. Macnick and his wife Susana Martinez-Conde turned to magicians as an experiment in thinking outside the box, hoping to glean insights into how the mind works from those following a tradition which takes advantage of its shortcuts and blind spots. The book that came of this collaboration, Sleights of Mind: What the Neuroscience of Magic Reveals about our Everyday Deceptions, is itself both surprising and seemingly inevitable (the website for the book). What a perfect blend of methods and traditions in the service of illuminating the mysteries of human perception and cognition. The book begins somewhat mundanely, with descriptions of magic tricks and how they’re done interspersed with sections on basic neuroscience. Readers of Skeptic Magazine or any of the works in the skeptical tradition will likely find the opening chapters hum-drum. But the sections have a cumulative effect.
The hook point for me was the fifth chapter, “The Gorilla in Your Midst,” which takes its title from the famous experiment conducted by Daniel Simons and Christopher Chabris in which participants are asked to watch a video of a group of people passing a basketball around and count the number of passes. A large portion of the participants are so engrossed in the task of counting that they miss a person walking onto the scene in a gorilla costume, who moves to the center of the screen, pounds on his chest, and then walks off camera. A subsequent study by Daniel Memmert tracked people’s eyes while they were watching the video and found that their failure to notice the gorilla wasn’t attributable to the focus of their gaze. Their eyes were directly on it. The failure to notice was a matter of higher-order brain processes: they weren’t looking for a gorilla, so they didn’t see it, even though their eyes were on it. Macnick and Martinez-Conde like to show the video to their students and ask the ones who do manage to notice the gorilla how many times the ball was passed. They never get the right answer. Of course, magicians exploit this limitation in our attention all the time. But we don’t have to go to a magic show to be exploited—we have marketers, PR specialists, the entertainment industry.
At the very least, I hoped Sleights of Mind would be a useful compendium of neuroscience concepts—a refresher course—along with some basic magic tricks that might help make the abstract theories more intuitive. At best, I hoped to glean some insight into how to arrange a sequence of events to achieve that surprising and inevitable effect in the plots of my stories. Some of the tricks might even inspire a plot twist or two. The lesser hope has been gratified spectacularly. It’s too soon to assess whether the greater one will be satisfied. But the book has impressed me on another front I hadn’t anticipated. Having just finished the ninth of twelve chapters, I’m left both disturbed and exhilarated in a way similar to how you feel reading the best of Oliver Sacks or Steven Pinker. There’s some weird shit going on in your brain behind the scenes of the normal stuff you experience in your mind. It’s nothing new for people with a modicum of familiarity with psychology that there’s an illusory aspect to all our perceptions, but in reality it would be more accurate to say there’s a slight perceptual aspect to all our illusions. And one of those illusions is our sense of ourselves.
I found myself wanting to scan the entire seventh chapter, “The Indian Rope Trick,” so I could send a pdf file to everyone I know. It might be the best summation I’ve read of all the ways we overestimate the power of our memories. So many people you talk to express an unwillingness to accept well established findings in psychology and other fields of science because the data don’t mesh with their experiences. Of course, we only have access to our experiences through memory. What those who put experience before science don’t realize is that memories aren’t anything like direct recordings of events; they’re bricolages of impressions laid down prior to the experience, a scant few actual details, and several impressions received well afterward. Your knowledge doesn’t arise from your experiences; your experiences arise from your knowledge. The authors write:
“As the memory plays out in your mind, you may have the strong impression that it’s a high-fidelity record, but only a few of its contents are truly accurate. The rest of it is a bunch of props, backdrops, casting extras, and stock footage your mind furnishes on the fly in an unconscious process known as confabulation” (119).
The authors go on to explore how confabulation creates the illusion of free will in the ninth chapter, “May the Force be with You.” Petter Johansson and Lars Hall discovered a phenomenon they call “choice blindness” by presenting participants in an experiment with photographs of two women of about equal attractiveness and asking them to choose which one they preferred. In a brilliant mesh of magic with science, the researchers then passed the picture over to the participant and asked him or her to explain their choice—only they used sleight of hand to switch the pictures. Most of them didn’t notice, and they went on to explain why they chose the woman in the picture that they had in fact rejected. The explanations got pretty elaborate too.
Part 2 of this essay.