About 4 percent of the people on Earth experience a mysterious phenomenon called synesthesia: They hear a sound and automatically see a color; or, they read a certain word, and a specific hue enters their mind’s eye. The condition has long puzzled scientists, but a small new study may offer some clues.
The study, published today (March 5) in the journal Proceedings of the National Academy of Sciences, offers insight into what might be happening in the brains of people with synesthesia.
Previous “studies of brain function using magnetic resonance imaging confirm that synesthesia is a real biological phenomenon,” said senior study author Simon Fisher, director of the Max Planck Institute for Psycholinguistics in the Netherlands. For example, when people with synesthesia “hear” color, brain scans show that there’s activity in the parts of the brain linked to both sight and sound, he said. (Not all people with the condition “hear” sights, however; the condition can also link other senses.)