It ’s a enigma that ’s challenged some of science ’s greatest minds , including Charles Darwin , Galileo , Francis Bacon , and Plato [ PDF ] . One thing is for sure : It ’s not becausewe find it funny . In fact , many people find tickling very unpleasant . So why does it make us express mirth ?
There aretwo form of tickle phenomenon : Gargalesis , the heavy tickling that produces laugh , especially by target sensible areas like the axilla and tummy ; and knismesis , which is cause by light movement and tend to elicit an itching mavin rather than laugh . You ca n’t thrill yourself because your brainknows it ’s coming .
When the face endings in your epidermis are stimulated by a light touch , theysend a signalthrough the nervous system to your brain . Using operative magnetic plangency imagery machines ( fMRI ) , researchers have determined that two areas of the brain create that tickling sensation : the somatosensory pallium , the country responsible for analyzing touch , and the anterior cingulated cerebral cortex , which is involved in creating pleasurable feeling .
Another fMRI studyhas shownthat both express joy at a joke and express mirth while being tickled activate an area of the brain holler the Rolandic Operculum , which controls facial movements and outspoken and emotional reaction . But tickle laughter alsoactivates the hypothalamus , the area of the psyche that regulates the scrap or flight response — and fires when you ’re predict nuisance . This has lead some scientist to believe that laughing when you ’re tickled could be a natural signal of entry to an aggressor , which would reduce the duration of any attack . It also explains why we may express mirth at just thethreatof being tickled .
Robert Provine , neuroscientist at the University of Maryland , Baltimore County and author of the 2000 bookLaughter : A Scientific Investigation , says that laughter during tickle creates bonds between infant and parents . “ When people say they hate being thrill and there ’s no reason for it , they leave that it ’s one of the first avenue of communicating between mothers and babies,”he told Slate . “ You have the mother and baby engaged in this sort of primordial , neurologically program interaction . ”
We ’re not the only animals that laugh when we ’re tickled : Great ape giggle , andso do strikebreaker .
