It’s perfectly normal for someone to laugh uncontrollably when tickled, although some of us are more ticklish than others, but researchers at the University of California, San Diego, recently reported the unusual case of a woman who would burst into laughter when seeing other people being tickled.
Referred to only as TC, the woman was apparently seeking help for her bizarre condition – whenever she saw someone getting tickled, she could feel the sensation on her own skin and would start to laugh uncontrollably as if she was the one getting tickled. Researchers conducted a series of experiments to explore the bizarre phenomenon further and concluded that the woman suffered from a rare condition known as mirror-touch synaesthesia. It is believed to be caused by mirror neurons, connectors in the brain that react the same way when an event is experienced or when it’s simply observed.