Magic

november 2008 volume 9 no. 11 www.nature.com/reviews

NEUROSCIENCE

PROTEIN DEGRADATION
Molecular insights into neuronal function and dysfunction

Long-term potentiation
Breaking the synaptic silence

PerSPectiveS
Science and Society

Attention and awareness in stage magic: turning tricks into research
Stephen L. Macknik, Mac King, James Randi, Apollo Robbins, Teller, John Thompsonand Susana Martinez-Conde

Abstract | Just as vision scientists study visual art and illusions to elucidate the workings of the visual system, so too can cognitive scientists study cognitive illusions to elucidate the underpinnings of cognition. Magic shows are a manifestation of accomplished magic performers’ deep intuition for and understanding of human attention and awareness. By studyingmagicians and their techniques, neuroscientists can learn powerful methods to manipulate attention and awareness in the laboratory. Such methods could be exploited to directly study the behavioural and neural basis of consciousness itself, for instance through the use of brain imaging and other neural recording techniques.
Magic is one of the oldest and most wide­ spread forms of performance art1(FIG. 1). It is also a discipline with a long legacy of infor­ mal experimentation. This informal research by magicians aims to determine what condi­ tions allow for the maximum manipulation of human attention and perception. Much as early filmmakers experimented with editing techniques to determine which technique would communicate their intent most effectively, magicians have explored thetechniques that most effectively divert atten­ tion or exploit the shortcomings of human vision and awareness. As such, magic is a rich and largely untapped source of insight into perception and awareness. Insofar as the understanding of behaviour and perception goes, there are specific cases in which the magician’s intuitive knowledge is superior to that of the neuroscientist. In this Perspective, weunderline potential areas in which neuro­ scientists stand to reap great benefits from collaboration with the magic community (BOX 1 highlights one such potential area of collaboration). Using completely natural means, magi­ cians create effects (magic tricks) that seem to be outside the laws of nature. One should note that, unlike so­called psychics, magi­ cians do not claim to possess supernaturalnATUre reVIeWs | neuroscience

powers. The devices used by magicians can include one or more of the following: visual illusions (after­images), optical illusions (‘smoke and mirrors’), cognitive illusions (inattentional blindness), special effects (explo­ sions, fake gunshots, et cetera), and secret devices and mechanical artifacts (gimmicks). Visual illusions — and other sensory illusions —are phenomena in which the subjective perception of a stimulus does not match the physical reality of the stimulus. Visual illusions occur because neural circuits in the brain amplify, suppress, converge and diverge visual information in a fashion that ultimately leaves the observer with a subjective perception that is different from the reality. For example, lateral inhibitory circuits in theearly visual system enhance the contrast of edges and corners so that these visual features seem to be more salient than they truly are2–6. Unlike visual illusions, optical illusions do not result from brain processes: they manipulate the physical properties of light, such as reflection (using mirrors) and refraction (a pencil looks broken when it is placed upright in a glass of water owing to thedifferent refraction indices of air and water). Cognitive illusions can be distinguished from visual illusions in that they are not sensory in nature: they

involve higher­level cognitive functions, such as attention and causal inference (most coin and card tricks used by magicians fall into this category). The application of all these devices by the expert magician gives the impression of a...