Curiosity corner-Why do we laugh when we are tickled?
Touch is an extremely powerful thing. Humans clearly respond to touch, both physically and emotionally. Some areas on our bodies are more sensitive than others, however. Laughing when tickled in our sensitive spots (under the arms, near the throat and under our feet) could be a defensive mechanism.
Beneath your skin lie millions of tiny nerve endings that alert the brain to all manner of touch. When these nerve endings are lightly stimulated — for example, by another person’s fingers or by a feather — they send a message through your nervous system to your brain, which analyzes the message. Using functional magnetic resonance imaging machines (fMRI), researchers have determined that the effect of a light touch that results in a tickling sensation is the result of the analysis of two regions of the brain.
The somatosensory cortex is responsible for analysing touch; for example, the pressure associated with it. The signal sent from the skin’s sensory receptors also passes through the anterior cingulated cortex, which governs pleasant feelings. Together, these two create the tickle sensation. Therefore, when we are tickled the somatosensory cortex picks up the signals to do with pressure, but the anterior cingulated cortex also analyses the signals which leads to pleasurable feelings.
We laugh when we’re tickled because both tickling and laughing activate theRolandic operculum — a part of the brain that controls facial movement, vocal, and emotional reactions. Furthermore, the laughter from being tickled is part of a defence mechanism to signal submissiveness and the researchers believe that our responses to tickling date back to man’s earliest evolution and developing self-awareness.
Ref: http://www.thehindu.com/todays-paper/tp-features/tp-educationplus/question-corner/article8062028.ece
