And what effect does synesthesia have on creativity? Marks explains that creative cognition (essentially an aspect of creativity)—a test of which might ask its subject to conjure as many non-traditional uses for an object like an umbrella as possible—“seems to produce higher scores among populations with synesthesia.” Studies have suggested, as he noted
in a 2014 article, “that people with synesthesia do have enhanced creative abilities, creative cognition.”
Cytowic corroborates that “synesthesia is more common among artists than it is among the general population.” And moreover, “even those who aren’t performing artists or, let’s say, ‘working artists’—they [still] will play musical instruments, they’ll know a foreign language or two, they’ll be expert knitters or potters. They’ll have some sort of creative hobby in their lives.”
Plenty of people may experience degrees of conjoined senses, and it’s even been proposed that nearly everyone experiences “weak” forms of synesthesia, a sort of cross-talk between different senses in the brain (Steen mentions the combined smelling and tasting of food as one example). But what constitutes actual synesthesia?
Research has come a long way, but the conception and definition of synesthesia is constantly evolving, and researchers still have a lot to discover in the relatively young field. For instance, Cytowic notes, brain scans alone don’t tell the whole story, and can even be misleading. He mentions an area in the brain (known as V4, or the “color center”) often associated with synesthesia; it tends to “activate” in fMRI scans. “I don’t want people to point to V4 and say, ‘There it is, there’s synesthesia,’” Cytowic cautions. “Many, many other areas are active in this network that supports synesthesia.”
In addition to neuroimaging, though, a variety of behavioral tests can confirm whether someone in fact has synesthesia, Marks explains. A researcher might quiz a potential synesthete about what color associations they have with specific letters of the alphabet. “Then you ask them two years later about the same letters,” he says. “Synesthetes are remarkably consistent over very long periods of time.” Cytowic also adds that the difference between synesthetes—versus those who only claim to be—is that while individual experiences may be quite specific, in general “synesthetes all basically tell the same story” as others who share their version of synesthesia.
But regardless of all the advances over the last 40 or so years, “the study of synesthesia,” Steen says, “frankly, is in its infancy.” There is much more to be done and to uncover, and opinions often differ.