Researchers reveal how our brains know when something's different

Imagine you are sitting on the couch in your living room reading. You do it almost every night. But then, suddenly, when you look up you notice this time something is different. Your favorite picture hanging on the wall is tilted ever so slightly. In a study involving epilepsy patients, National Institutes of Health scientists discovered how a set of high frequency brain waves may help us spot these kinds of differences between the past and the present.