Lightly trailing a feather or a finger over the instep of someone's foot usually causes several predictable reactions: The person laughs, giggles or becomes irritated, instinctively draws his foot out of reach and does his utmost to avoid being tickled a second time. Michael Nirenberg of the America's Podiatrist website says having ticklish feet is a good thing for a variety of reasons. Researchers who have conducted experiments on ticklishness still don't have all the answers as to why humans and other animals, such as cats, rats and monkeys, are ticklish or what exactly goes on between nerve endings and the brain during tickling. Because nerves on the foot's sole have both touch and pain receptors that carry information about either sensation along neural pathways to the brain, it's difficult to separate the two when talking about ticklishness, says the American Scientist website. The pain and pleasure of having your feet tickled is linked to these pain and touch nerve tracts. Add to that the anticipation of the tickle, and the whole business invokes a "tonic top-down regulation of neural activity," as reported in MIT's "Journal of Cognitive Neuroscience"—which means the brain is primed and ready to react before the feather touches skin. It also explains why a person can't tickle himself: The surprise factor is absent because the tickler is in control of tickling of his own body part and knows it.
Knismesis vs. Gargalesis
Neighbourly Advice According to Ed
Have you ever tip-toed through the tulips? If so, the tulips probably tickled your toe tips! If you've ever had someone run a feather or fingertip across the bottom of your foot, you know how incredibly ticklish your feet can be. But why is that? Along with your underarms, your feet are two of the most ticklish spots on your body.
Neighbourly Advice According to Ed. Ed, my old neighbour, in Saskatchewan loves to tickle his grandchildren. His grandchildren keep a cautious eye on him in case he might grab them and tickle them. Some of his grandkids are incredibly ticklish, and Ed has never understood, until now, how being tickled may not be what others want to experience. It was a trip to Edmonton that turned Ed into a marshmallow when he endured having his feet tickled. At West Edmonton Mall, Ed was pressured into getting a pedicure. Toenails that are too long and hard to cut are not that uncommon. Since it was Edmonton, and no one would ever know in Saskatchewan that Ed had his toenails cut by a stranger in Alberta, he experienced his first and last pedicure there. Ed found that there was a lot more to a pedicure than having his toenails cut.
Some people feel unbearable discomfort when the soles of their feet are brushed during a pedicure. Your sensitivity level to tickling is known as the tickle response. Scientists have analyzed the tickle response in feet and in other parts of the body, but continue to wonder what purpose being ticklish serves.