Magicians like David Blaine, Penn and Teller could soon have a new trick up their sleeves: brain imaging. Functional-MRI scans of people watching magic tricks implicate two brain regions that are activated by sights such as levitating objects and other events that don鈥檛 add up.
Brain scans effectively serve as 鈥渁 lie detector for magic tricks鈥�, says Ben Parris, a neuroscientist at the , UK, who led the study.
Perhaps more importantly than improving magicians鈥� acts, Parris says the results shed light on how our brains deal with incongruities.
Advertisement
A previous attempt to answer this question saw volunteers learn arbitrary relationships 鈥� red goes with a happy face and blue a sad face, for instance. Researchers then scanned the participants鈥� brains to see what happens when these mental links are violated.
Abracadabra
In this experiment, Parris鈥檚 team probed violations of more ingrained relationships. For instance, when a person snatches a coin with one hand, we expect to see the coin when he reopens his hand 鈥� even if he is sporting a top hat and wand.
Parris鈥檚 team showed 25 volunteers videos of magic tricks as they lay in an fMRI scanner. As a control, volunteers viewed the same magician perform unsurprising acts 鈥� for instance, he opens his hand and the coin is still there.
The researchers also scanned the brains of subjects watching surprising acts that don鈥檛 breach the laws of physics 鈥� the magician opens his hand to reveal a coin and someone slaps the coin out.
Two brain areas seemed to be critical to witnessing magic tricks 鈥� the anterior cingulate cortex (ACC) and the left dorsolateral prefrontal cortex (l-DLPFC). While neither spot could be called the brain鈥檚 鈥渟eat of magic鈥� 鈥� as if such a place existed 鈥� visual tricks might tap into basic cognitive calculations performed in these areas, Parris says.
Performance enhancer?
For its part, the ACC helps detect conflict between what happens and what is expected to happen, while the l-DLPFC may be involved in resolving such ambiguities. Other studies probing disbelief have implicated the same regions.
Individual differences in activation of these areas may mark the difference between the gullible and the shrewd, Parris says.
鈥淚 thought that it was a very complete study,鈥� says , a neuroscientist at Barrow Neurological Institute in Phoenix, Arizona. She says it is important to distinguish everyday surprise from the visual trickery of magic. 鈥淭here鈥檚 an element of surprise and there鈥檚 an element of disbelief.鈥�
As for the prospects of birthday-party magicians turning to an fMRI to hone their next trick, Martinez-Conde is sceptical 鈥� at least for the time being. 鈥淭he costs would be quite prohibitive.鈥�
Journal reference: (DOI: 10.1016/j.neuroimage.2008.12.036)
