Why are we ticklish? 人怕撓癢癢的原因



Why are we ticklish? 人怕撓癢癢的原因


有關 「the body’s reactions 身體反應」 的詞彙


Why isn’t being tickled always enjoyable?


Professor Sukhi Shergill, Psychiatry and Systems Neuroscience, King’s College London
Tickling: love it, or hate it? Or even a bit of both… It’s a strange phenomenon.

蘇基‧謝吉爾    倫敦大學國王學院精神病學與系統神經科學教授
「被人撓癢癢這種感覺:你是喜歡還是討厭?或者都有一點… 這是個奇怪的現象。」

There are two types of tickling sensation. Knismesis – a mildly annoying feeling caused by light movement like this. And there’s gargalesis – which is caused by a deeper pressure on your skin.

When your skin is touched, the nerve endings underneath send electrical signals to the brain. We laugh when we’re tickled because the sensation is picked up in two areas of the brain at once – the part which analyses touch, but also the part that creates pleasure.
But of course, being tickled isn’t always enjoyable.

In fact, it also affects the part of the brain that makes you feel panic in the face of danger.
So, strange as it may seem, laughing when you’re tickled could be a sort of primitive defence mechanism – giving a signal to show our submission to a predator.

So, why can’t we tickle ourselves? We think it’s to do with the brain’s cerebellum that monitors our movement. It can tell the difference between expected and unexpected sensations. In other words, it already knows what you’re doing and is too clever to react.


tickling sensation 癢的感覺,發癢

nerve endings 神經末梢

electrical signals 電子信號

defence mechanism 防禦機制、防衛表現


Because it affects two parts of the brain, including one that makes us feel panic.