When I was about 6, my mind did something wondrous, although it felt perfectly natural at the time. When I encountered the name of any day of the week, I automatically associated it with a color or a pattern, always the same one, as if the word embodied the shade. Sunday was dark maroon, Wednesday a sunshiny golden yellow, and Friday a deep green. Without knowing it, I was living the unusual mental state called synesthesia, aptly described by psychology professor Emma Geller as a "condition in which ordinary activities trigger extraordinary experiences." More exactly, it is a neurological event where excitation of one of the five senses arouses a simultaneous reaction in another sense or senses (the Greek roots for "synesthesia," also spelled "synaesthesia," translate as "joined perception").

My tongue is orange!" my 2-year-old daughter shrieked after licking a dollop of clear hand sanitizer. "Mommy, my ear feels orange," she moaned when an earache struck. It's orange," she whined from inside her snowsuit when a scratchy tag in her new white glove rubbed uncomfortably against her wrist. As her vocabulary blossomed, she started to associate colors with scents. "What smells pink?" (Dryer exhaust puffing out of a neighbor's basement vent.) Anyone who has spent time around toddlers knows they say some strange things.

I remember the first time I was introduced to the concept of synesthesia. I was in seventh grade, sitting in the dark, watching an educational video about the neuroscience of the phenomenon in lieu of our typical life science coursework. A British woman with lexical-gustatory synesthesia appeared on screen to describe the way every name she'd ever spoken had a different taste. Many of the particulars of the documentary have faded in the decade since I last saw it, but I still recall the woman saying "the name Catherine tastes like chocolate cake." For years, I have wished (perhaps unfairly) that I had synesthesia, a rare neurological condition where senses enterwine.