Why Do We Laugh When We're Tickled - Greg foot - Ask head squeeze

Hey Head Squeezers! I hope you're well and welcome to the first Ask Head Squeeze Thursdays! Now as promised in my announcement video last week I'm going to be looking at You Tuber James The Weirdo's question all about tickling. Don't even think about it! Now in this film I'm going to uncover why we can't tickle ourselves and also which animals laugh when tickled? But first, feather dusters at the ready. Not you. What is a tickle? Now if you peeled off your epidermis, the top layer of your skin you'd see hair follicles, sweat glands, muscles, nerve endings and probably quite a lot of blood. It's those nerve endings we're interested in. They connect to nerve fibres that make up the whole central nervous system throughout your whole body. When you are touched the nerve endings pick up heat, cold, pressure, the amount of time you've been touched for and that gets sent as electrical signals to your brain. Now as you know when you've been tickled it's normally a very light touch that sets off that ticklish feeling. But why? Well there are two parts of the brain responsible for analysing all these signals. Now we know this because people have kindly jumped in big metallic tubes and been tickled for science. Oh yes! Now fMRI studies have shown that it's the somatosensory cortex in the brain that analyses the data to do with touch, so pressure. But it's also being analysed by the anterior cingulate cortex, that governs pleasurable feelings and it's a weird combination of the two. So why can't we actually tickle ourselves? Well that is down to the cerebellum at the back of the brain. It's the bit that governs your movements and it predicts a self tickle. It tells your brain that you're about to tickle yourself. But why? Why does this happen? Well if you think about it our brains are getting bombarded by information all the time and you don't want to be overloaded so it filters out some of that noise allowing us to focus on the important stuff. Here's a question though. Why do people laugh when they're tickled? Well step up two gentlemen. The first one Charles Darwin, he of fantastic illustrious beard and Ewald Hecker, he of also magnificent facial hair but also more on top than Mr Darwin here. They both said that ticklishness is related to humour that you need to be in a good mood to have both of them. Kind of makes sense. However, well done on the finches Mr D but this one is slightly off. Think about it, if you're watching fail videos on YouTube and you're chuckling away at yourself you won't be more prone to ticklishness than normal. So we don't laugh because it's funny so why do we laugh when we're tickled? Well the clue to this comes when you realise that the most vulnerable bits of your body for ticklishness are also the most vulnerable bits of your body for injury. Now evolutionary biologists and neuroscientists say that when you laugh you're showing you're submission to an aggressor. In other words if someone comes and attacks you, you chuckle about it and that diffuses the situation. It's supported by research that shows that the parts of your brain that fire when you're having ticklish laughter are also the parts of your brain that fire when you're anticipating pain. Think about which parts of your body make you laugh when you're tickled. So underneath your arms, yeah there's kind of a lot of arteries there and also it's a straight root around your rib cage to your heart. Your neck, you've got loads of arteries there but you've also got your trachea as well and of course the soles of your feet. Yeah now they are covered in very highly sensitive receptors known as meissner corpurscles. Ok BONUS FACT time! If you were to tickle a gorilla, not a good idea but alright if they've been hand reared you would notice that their response is quite similar to that of a tickled human. And if you analyse the sounds they're also very very similar to when we are tickled and we laugh. That suggests to researchers that laughing when tickled is a very very old response, shared by a common ancestor of both the great apes and us which puts that response at something like 30 to 60 million years old. BONUS BONUS FACT! Other animals also laugh when they're tickled including rats. Oh yeah of course scientists have tickled rats in the name of science. What they found is that they do giggle away at about 50kHz, which is outside of our audible range. So you wouldn't actually know if there was a giggling rat in the room next to you. So there you go that's the full low down on tickling. Why you actually feel a tickle and how you feel it, why you can't tickle yourself, why we laugh when we get tickled and also the fact that gorillas and rats also laugh when tickled. So now you know. Now of course there's going to be more of these Ask Head Squeeze videos every Thursday answering your questions so let us know. What do you want to know? Put it in the comments down below this video or subscribe and join our G+ community page and send them in that way. Until next time, happy Head Squeezing. Just getting back to business.