[인지신경과학] Magic and attention

  Related to this essay, I’d like to introduce a magic that I learned a few years ago then explain the internal mechanism of the magic with the cognitive neuroscience topic-visual attention. The magic is predicting the card which a person chooses and the point of this magic is ‘predicting’ which means the magician knows before the participant chooses a card. The following is the process of this magic and M refers magician, A refers assistant of the magician, and P refers participant who don’t know trick of this magic.

i. M shuffles the cards then indicates P to take some cards as many as P wants and choose one card he or she likes.
ii. Before P chooses one card, M writes down the shape and number of the card which will be chosen by P. And then M gives the written paper to A not to manipulate the prediction.
iii. After P chooses the card, M indicates P to put that card on the several cards that P took at stage i.
iv. M puts cards left after P chose on the cards which P has at stage iii.
v. M indicates A to unfold the written paper and read the information of the card then choose the appropriate card among the whole cards.
vi. A shows the card to P which is exactly same as P chose at stage i.

  The tricks behind this magic are in the stage ii and iv. In the sage ii, M writes down information for the card which P will choose but exactly, M writes information not the card itself. M writes “Pick the cards which is right side of the (for instance) Clover 4 (M should catch the card quickly which is at the bottom of the left card.) Then in the stage iv, M puts the left cards on the cards that P gives to M and later A turns off the whole card to the direction from the right to the left. Finally the card P chose will be always seen right side of the Clover 4. 

  In this magic, usual people give their attention according to instruction of magician or the opposite direction for resisting from tricks. For example, they would struggle to select a card which may be too hard to predict for magician they think because of its shape or number. Or they would gaze the magician not to deceive them after they chose one card. But all the above are intended idea of magician. (Therefore it can be related to endogenous attention) Showing exaggerated considering behavior for the unknown card triggers scattered attention of participants from subtle actions of magician because exaggerated behaviors are more salient then it catches their visual attention more easily. Also, early adapted belief like magician will steal a glance for my card rather than magician will write down on the paper differently can trigger higher level of neural feedback for the visual attention to go (attend) on only that belief.

  By the way, how brain of the participants change when they become to know tricks of magic? They will say ‘A-HA!!’ or something. I heard similar articles about this topic related to attention and consciousness. Those articles say that when they become to know something (of course they couldn’t pay attention to) their brain shows surprising activation. Two regions of the brain which are far from each other get to be fired simultaneously when unattended and unknown (or unconscious) things come to their mind.

  So I think that being fooled by magical tricks or catching the secret of the magic is related to activities our brain relevant to attention and consciousness, and it’s really interesting but little ultimate topics.