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.
