Mirror-touch synesthesia (MTS) is a condition that approximately two in 100 people have, and it involves of physically feeling something that is happening to someone else. New research investigates this condition, revealing new insight into how common it actually is.

The study, published in the journal Cortex, was carried out by researchers at the University of Delaware and it was conducted on more than 2,000 students who were enrolled in an introductory psychology course.

Mirror-Touch Synesthesia

The students volunteered as participants in the research. According to the researchers, some of the students who had this condition were not aware that their experiences were in any way different compared to the rest of the population.

"But if you have mirror-touch synesthesia, there's nothing wrong with you. It's just an interesting difference, like being double-jointed," noted Jared Medina, assistant professor in the university's Department of Psychological and Brain Sciences.

As part of the research, each subject had to sit at a table with the hands oriented either palms down or up. The subjects were shown videos of hands being touched in various locations, on the surface or on the palm. The subjects were then asked if they felt anything while watching the videos, where they felt it and how strong the sensation was.

Additionally, a second experiment was carried out, as part of which reaction times were tested, for the scientists to check whether the students were faking the reactions or they were actually feeling them. After this second experiment, a number of 45 students were identified to have the MTS condition, from the total of 2,351 undergrads who took part in the study.

However, the sensations of the subjects weren't always the same. Differences were spotted among the participants, especially when the subjects' hands were positioned differently compared to the ones illustrated in the videos.

The differences were divided into two different groups of phantom feelings: one group felt the touch on the part of the hand which was faced up, regardless of the position of the hand shown in the video, while the other always felt the touch on the part of the hand touched in the video, regardless of their own hand position.

At the same time, when the subjects' hand positions were the same as the ones in the video, most of the participants felt the touch in the same part that was being touched in the video.

"[...] Participant response patterns varied as a function of postural congruence. Some participants consistently felt sensations on the hand surface that was stimulated in the video - even if their hands were in the opposite posture. Other participants' responses were modulated based on their own hand position, such that percepts were more likely to be felt on the upright, plausible hand surface in the posturally incongruent condition," noted the research.

Synesthesia, A Common Perception Oddity

According to the researchers who conducted this study, synesthesia can be manifested in different ways. For instance, people may perceive colors differently, or they can experience taste when they see someone eating or drinking something.

Among the most popular people who are known to have suffered from synesthesia, Vincent van Gogh, Vladimir Nabokov, and Marilyn Monroe are popular for this odd occurrence in their perceptions. Additionally, Richard Feynman, the Nobel Prize-winning physicist, also suffered from synesthesia, and he often noted seeing equations in different colors.