You’ve probably heard Mondays referred to as “blue,” or a brightly colored shirt as “loud.” For most people, these descriptions are figurative. Mondays don’t really conjure a turquoise haze, and shirts don’t emit high-pitched screeches. But for some people, called synesthetes, such cross-sensory experiences are quite literal.
When Carol Steen, now in her sixties, was a girl growing up in Detroit, she used to walk home from elementary school with a friend. One day, perhaps after a lesson in spelling or an exercise in handwriting, seven-year-old Steen asked her classmate, “Isn’t the letter ‘A’ the prettiest pink?” Her classmate, in the way only kids can, wrinkled her nose and pronounced Steen “weird.”
That was the first time Steen realized that not everyone saw beautiful, intense colors in letters and numbers like she did. It was also the last time she talked about it, until thirteen years later at the family dinner table. “The number five is yellow,” Steen commented. Her mother and brother looked at her blankly, but her father disagreed. “No,” he said. “It’s yellow-ochre.”
What Is It?
Synesthesia, from the Greek syn for “together” and aisthēsis for “sensation,” is a neurological condition (Steen would say “ability”) in which one sensory experience automatically and consistently triggers another sensory or cognitive perception. A synesthete might literally see sound or taste color.
Today, synesthesia is believed to be far more common than once thought, occurring in as many as one in twenty-three people. There are more than sixty documented forms of synesthesia, covering all five senses, but some are more frequent than others:
Grapheme-color synesthesia: With the most common form of synesthesia, grapheme-color synesthetes perceive very definite colors in units of written language, like numbers or letters, called “graphemes.” For example, “A” is scarlet-red, or “7” is lime-green.
Number-form synesthesia: Numbers, months, years, days, or dates—anything with a serial order—are attributed with a place in space. For example, the months of the year might be seen as situated like the numbers on the face of a clock, or 2008 might appear further away or higher or lower than 2003.
