You Can't Tickle Yourself

You can't tickle yourself. Try it right now — put your hand on your own ribs and do it properly. Nothing. Now imagine someone else doing exactly the same thing. Same ribs, same fingers, same pressure. You'd be on the floor. In the late nineties, researchers at University College London built a robot that let people tickle themselves through a machine. It did nothing — until they added a delay of a tenth of a second. Then it tickled. The longer the delay, the more it felt like somebody else's hand. Your brain predicts everything you're about to feel and subtracts it before it reaches you. And in a second experiment, the same team found out what that means between two people: when they try to return each other's pressure exactly, the force goes up by roughly 40% every turn — and both are certain the other one started it. This video is about the version of you that your brain removes, and why the people around you have always felt more of you than you have. CHAPTERS 0:00 You can't tickle yourself 0:30 The robot and the tenth of a second 1:10 Your brain subtracts you 1:43 You've never seen yourself blink 2:12 Two fingers, 40% every turn 3:10 Every argument you've ever had 4:02 Why the deletion protects you 4:38 Try this tonight Sources: Blakemore, Wolpert & Frith on self-produced tickle; Shergill, Bays, Frith & Wolpert (Science, 2003) on force escalation. Subscribe for more of the machinery running underneath your life. #psychology #neuroscience #brain