The first step in accepting the need for skepticism and a systematic, scientific approach to evaluating medical therapies is understanding the limitations of our perceptions and judgments. Human beings all share innate and inescapable blind spots, both sensory and cognitive, that leave us vulnerable to misconceptions. And unfortunately, our sense of certainty about what we know is not a reliable guide to whether we are actually correct in our beliefs.
So I have a fascination for neuroscience in general, and especially the study of how our brains generate our perceptions, beliefs, and misconceptions. I was recently given a brilliant book on this subject which I thought might be of interest to some readers even though it is not specifically about the subject of medicine. Sleights of Mind: What the Neuroscience of Magic Reveals about our Everyday Deceptions by Stephen Macknik and Susana Martinez-Conde.
The authors are neuroscientists who specialize in the way the brain handles vision. As experts on visual processing, they are especially familiar with the ways in which our visual sense can misrepresent the world, and can be fooled by skilled manipulators of perceptions such as magicians. Both authors are founding board members of the Neural Correlate Society, which hosts the annual Best Illusion of the Year contest.
However, in Sleights of Mind, the authors go well beyond the subject of optical illusions. They illustrate, through the performance art of magic, how we can be fooled by others and, most often, how we fool ourselves, due to a variety of neural mechanisms involving all the sense as well as “higher” functions such cognition, memory, expectation, and the illusion of free will.
Through examples and demonstrations by world-class magicians, Drs. Macknik and Martinez-Conde show us how consistently and dramatically we can be mislead even when we are warned in advance that a magician intends to fool us. And while they only occasionally refer specifically to how these sensory and cognitive blind spots lead us to false beliefs about healthcare, the applicability to medicine is quite clear. We are often wrong when we subjectively or informally evaluate a medical therapy because of the same blind spots that lead us to be easily fooled by magicians and con artists. And while not perfect, carefully controlled clinical research is far less susceptible to such errors and thus a more reliable foundation for judgments about the causes of disease and our treatment interventions.
The authors include many of the illustrations of the blind spots they discussion on their web site. From simple visual illusions to seemingly impossible failures of perception (such as the failure to notice clowns and people in gorilla suits standing right in front of you when your attention has been effectively directed elsewhere), these demonstrations should give us all cause for a healthy skepticism about our own judgment and beliefs. And the best part is that the process of seeing our weaknesses exposed is still entertaining and fun! I highly recommend Sleights of Mind not only because, as a skeptic, I think “it’s good for you” but also because it’s fun.