Some people can literally feel your pain … or pleasure, or other physical sensations. And scientists are trying to figure out why.

Synesthesia appears in different ways but involves one of your senses responding to unrelated stimulation. For example, some famous musicians have said that they see colors when they hear music. In mirror-touch synesthesia, people “report feeling touch on their own body when seeing someone else being touched,” a study in Cortex describes, while saying that they have found the positioning of body parts is important to this quirk in the human brain.

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The researchers used 45 subjects with mirror-touch synesthesia and showed them videos of hands being touched in different places. When the subjects had their hands in the same positions as the hands in the videos, they were more likely to report feeling the touch too.

“Our findings suggest that the brain is matching the video hand to their own hand, as if asking, ‘Could that be my hand?’” researcher Jared Medina said in a University of Delaware statement.

According to the university, it is estimated that 2 percent of people have this form of synesthesia. “Some of the students in our study didn’t know that what they were experiencing was different from the rest of the population, and it blew their minds,” Medina said. “It’s just an interesting difference, like being double-jointed.”

Another researcher, Carrie DePasquale, said some of those subjects would feel those kinds of sensations while watching movies, feeling what the characters were going through.

Learning about how this synesthesia works is not just for fun — it can tell scientists more about how our brains work, including how they digest information from our sense of touch.

“Our research is important for understanding variety in the human experience and how the mind works,” Medina said.

Source: Medina J and DePasquale C. Influence of the body schema on mirror-touch synesthesia. Cortex. 2017.

See also:

The Neuroscience of Self-Control

Stress Stops Our Senses from Learning Anything

Male Brains Can’t Multitask