"Humans have a hardwired process of attention and awareness that is hackable. When people focus on one thing, their brains automatically suppress everything that happens around it. ­Magicians have devised many techniques that exploit this 'tunnel vision.' People can pay attention in various ways. Magicians exploit 'top-down,' or deliberate, attention by, say, asking a person to scan a book. They capture 'bottom-up' attention with distracting displays such as doves fluttering out of a hat."