The Woman Who Sees Time as a Hula Hoop

Ed Yong in The Atlantic:

Imagine a calendar. Chances are you just thought about a rectangular grid, with time progressing from the top-left to the bottom-right. But around one percent of you may have pictured something different—a V, for example, or a hoop encircling your head.

These weird shapes are called “calendar forms.” They’re a type of synesthesia—the mental phenomenon where people involuntarily map one type of sensation onto another. Some associate letters or numbers with colors, others taste sounds or see smells, and people with calendar forms map time onto space. Sure, everyone does that to an extent—for example, we might picture numbers on a line going from left to right. But calendar forms are especially vivid and perceptually real—people actually see the units of time occupying the space around their bodies.

The English polymath Francis Galton first described calendar forms in 1880, and the phenomenon has been rarely studied since. But Vilayanur Ramachandran, a neuroscientist at the University of California, San Diego who has been studying synesthesia for a long time, has been slowly amassing and studying people with this odd perceptual quirk.

He met one such person, a 25-year-old woman named Emma, a year ago. Her calendar is a hula hoop, which stretches horizontally in front of her and touches her chest at one point—always December 31st, no matter the actual time of year. Emma uses her calendar to organize her life, attaching events to the various months and zooming around the hoop to access them.

More here.