Researchers measure the tickle response in humans and offer a theory as to why humans cannot tickle themselves

A team of researchers from Humboldt University in Berlin has measured several aspects of the tickle response in humans and developed a theory that explains why humans cannot tickle themselves. In her article published in the journal Philosophical Transactions of the Royal Society B: Life Sciencesthe group describes the study of physical responses to tickling in several volunteers.

Tickling or being tickled occupies a special place in the mammalian response—it doesn’t seem to serve any purpose. It has also turned out to be in need of explanation. Humans aren’t the only creatures to experience tickling — dolphins, chimpanzees, dogs, and rats all have a tickling response. In all groups, the reaction is almost the same – there is a moment of awareness, followed by a smile and a laugh. In this new attempt, the researchers set out to learn more about tickling. For this purpose they recruited 12 volunteers.

Each of the volunteers sat in a chair with their forearms and feet bare, ready for easy access by a partner who was the clitoris. Before the tickling, the volunteers had time to get to know each other a little. The researchers also filmed the action with GoPro cameras — one aimed at the face, the other at the body part to be tickled.

Studying the videos, the researchers found that, as expected, the first reaction to the tickling was a change in facial expression. At about 300 milliseconds, a smile began to form, closely followed by a change in breathing. Then, 200 milliseconds later, vocalizations began, generally in the form of a laugh. When the tickling followed, the researchers asked the person being tickled to rate how ticklish the sensations they felt. The researchers found that, as expected, the volunteers found their feet the most ticklish. They also found that as ticklishness ratings increased, laughter loudness also increased.

The researchers performed the same experiment a second time, but on the second attempt, asked the volunteers to tickle themselves while being tickled by their partner. And that, the researchers found, resulted in her partner-administered tickles being greatly reduced.

The researchers concede that they still have no idea what happens to the nervous system when tickling occurs, but theorize that the reason people can’t tickle themselves is because the brain sends signals that the tickling can prevent when we touch ourselves – otherwise people would giggle on their socks or scratch under their arms while putting.

© 2022 Science X Network