00:00What if the person you're talking to suddenly became someone else?
00:03Would you even notice?
00:05Most people would say, of course.
00:08Psychologists decided to test that.
00:10They stopped strangers on the street and simply asked them for directions.
00:14While they were talking, two workers carrying a large wooden door walked between them.
00:19For just a moment, the stranger stepped away.
00:22A completely different person took their place.
00:24Different face, different voice, different height.
00:27But most people never noticed.
00:31They kept giving directions to a completely different stranger.
00:35Your eyes saw the change, but your brain ignored it.
00:39So here's the real question.
00:41How much of the world are you seeing?
00:44And how much is your brain filling in for you?
