Tickle me, please? The science behind why tickling yourself just does not work!

One effective technique to cheer up a worn-out and possibly crabby child or adult is by making a few light strokes on the sole of the foot, the armpits, or other areas of the body that will eventually lead that person to a simpering fit of giggles. It is a fact that some people are more ticklish than others, vary among different places in the body, and depend on the situation at hand. In line with this fact, have you ever tried to tickle yourself just to see if it works the same way as others tickle you? If yes, then do you know why tickling yourself just does not work at all? This question has indeed baffled our minds because we know, that the sensation we produce can never win over or even come close to other people tickling us.

The part of the brain that is responsible for us to perceiving tickle is the S1 or the somatosensory cortex of the brain. A study by Blakemore, Wolpert and Frith (1998) used an fMRI to study the brain activity when stimulus was either internally produced or externally. Their study revealed that more activity was found in the somatosensory cortex when the stimulus was externally produced. In addition, they also found out activity in the cerebellum is the perpetrator behind this difference in stimulus source. The function of the cerebellum is to coordinate movement and to receive both sensory input from the body and motor input from higher cortical areas that command movement. Moreover, when a tactile stimulus is generated, less activity in the cerebellum occurs. Integrating the role of the somatosensory cortex, when the person himself generates tactile stimulus, the cerebellum suppresses the effects of stimulation, and the end result is diminished activity in the somatosensory cortex and with it, diminished perception of the tickle. This cancellation of the sensory consequences of a motor command is a phenomenon known as reafference.

It is evident that not only these brain mechanisms underlying the phenomenon of reafference are responsible. Other factors that need to be considered are the predictability of the stimulus, sexual influences, and the difference from person-to-person subjective experiences. Blindfolded individuals or individuals who have their eyes are closed provide the greatest tickle sensation. Lastly, it was also discovered that the sensation could be greater if tickled by someone of the opposite sex. So if you want to burst into laughter after a crazy day in school or work, do not make attempts to tickle yourself because that just wouldn’t work. If there’s nobody to unexpectedly tickle you, then you might just have to find other ways like a video of a stand-up comedy show or the simplest joys of hearing a kid burst into laughter like this video below. Indeed, this baby tickled you in more ways than one.

Blakemore, S., Wolpert, D., & Frith, C. (1998). Central cancellation of self-produced tickle sensation.Nature Neuroscience, 1(7), 635-640. Retrieved from EBSCOhost.