Speaker 1: Welcome to brain Stuff, a production of iHeart Radio. Hey
Speaker 1: brain Stuff, I'm Lauren Bogelbaum, and today's episode is another
Speaker 1: classic from our prior host, Christian Sagar. This is one
Speaker 1: of our perhaps surprisingly rare episodes that's about actual brain stuff.
Speaker 1: It's about how tickling works and why most humans can't
Speaker 1: tickle themselves. Hey, I'm Christian Sagar, and this is brain Stuff.
Speaker 1: Pop quiz hot shot? Have you ever tickled an ape?
Speaker 1: Before it could work? As tickling is common between many
Speaker 1: types of primates. What about a rat? You ever tickled
Speaker 1: one of those? You'd know if you had, because rats
Speaker 1: let out these little, high pitched chirps when you tickle them,
Speaker 1: kind of like rodent laughter. Okay, so maybe some of
Speaker 1: you beast masters out there have tickled both a rat
Speaker 1: and an ape. But can you tickle yourself? Probably not,
Speaker 1: because that is kind of impossible. Now, but before we continue,
Speaker 1: let's do a quick primer on how tickling works under
Speaker 1: your skin. There are millions of nerve endings that alert
Speaker 1: your brain whenever you touch something. A light touch, what
Speaker 1: we usually associate with tickling, is analyzed by two regions
Speaker 1: of your brain, the somata sensory cortex, which processes touch,
Speaker 1: and the anterior singulated cortex, which processes happiness. Together they
Speaker 1: process the two types of tickle sensations we can experience.
Speaker 1: The first is nismesis. This is the light sensation you
Speaker 1: feel when something like a feather brushes against your skin,
Speaker 1: maybe giving you goose bumps. The second, gargolesis, is more
Speaker 1: like when your older brother holds you down and tickles
Speaker 1: you until you laugh so hard you pee your pants.
Speaker 1: This is the kind of tickling you can't replicate yourself.
Speaker 1: Evolutionary biologists believe that the reason we laugh when we're
Speaker 1: tickled is an innate, submissive response to a potential attacker.
Speaker 1: It's kind of like when a dog rolls were on
Speaker 1: its back and exposes its kill points to you. These
Speaker 1: same biologists theorized that we developed tickling so we could
Speaker 1: teach our children how to defend themselves from attacks. So
Speaker 1: think about it. The areas where we're the most ticklish,
Speaker 1: the under arms, the stomach, the neck, they're also the
Speaker 1: most vulnerable to attack. Now, this is some black Widow
Speaker 1: red room lethal training coming up here, So pay attention.
Speaker 1: Your under arm is home to veins and arteries, and
Speaker 1: because your rib cage doesn't protect it. Someone could easily
Speaker 1: access your heart through there, especially with a long enough blade. Likewise,
Speaker 1: your stomach doesn't have any defensive bones, and your neck
Speaker 1: also has two important arteries, as well as your tray
Speaker 1: chia bringing air to your lungs. Now, we're aware of
Speaker 1: all of these points of vulnerability, but we still can't
Speaker 1: tickle ourselves at them because our brains know that our
Speaker 1: own hands don't pose a legitimate threat. Essentially, you can't
Speaker 1: tickle yourself because of self awareness. Mri I studies have
Speaker 1: shown that your cerebellum actually alerts the rest of your
Speaker 1: brain when you're about to tickle yourself. This filters it
Speaker 1: out as unnecessary information and mutes the sensation. So theoretically,
Speaker 1: any situation that confuses your brain's ability to predict its
Speaker 1: own actions should allow you to tickle yourself right well.
Speaker 1: Sometimes schizophrenics, for example, can tickle themselves. This is probably
Speaker 1: because their brains sometimes attribute their behavior to an alien source.
Speaker 1: Researchers theorized that schizophrenic brains have biochemical or structural variations
Speaker 1: that keep the cerebellum from alerting its owner when they're
Speaker 1: about to tickle themselves. This means they can't tell the
Speaker 1: difference between their hands, your hands, or the tentacles of
Speaker 1: a giant splint. Today's episode was written by Christian and
Speaker 1: produced by Tyler Klang. For more in this and lots
Speaker 1: of other topics that will just tickle you because it
Speaker 1: has to Fox the com brain Stuff is production of
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Speaker 1: your favorite shows.