Neuroscientists have revealed that we cannot tickle ourselves (the gargalesis type) essentially because we can’t surprise our own brain. During a tickle, the skin’s nerve endings shoot electrical signals to the somatosensory cortex, a part of the brain that processes touch. Meanwhile, the anterior cingulate cortex analyzes these signals as either harmful or playful. But
in the back part of the brain, the cerebellum gives you away. It tells your cortex that you are about to attempt a self-tickle, and not to worry, it should suppress the signals from the tickle. So there is a brain system in place that analyzes the sensory input together with the motor output, basically telling us whether what we feel is due to ourselves or
others. And in doing so, it also helps us understand how the brain separates “me” from “them.” In fact, some people with dissociative disorders like
Schizophrenia can tickle themselves silly. Being able to
differentiate the actions of others and ourselves is central to our sense of self.