Synesthesia 101: Definition, Causes + A Simple Test To Find Out If You Have It

Of all the phenomena of the brain, synesthesia is one that's equally fascinating and mysterious. Characterized by senses essentially overlapping (i.e., hearing and vision, or hearing and taste), here's what to know about synesthesia, signs of a synesthete, and a test to find out if you have it yourself.

"Synesthetes can often 'see' music as colors when they hear it, and 'taste' textures like 'round' or 'pointy' when they eat foods. Another example of synesthesia is seeing the same color every time you see a certain number or hearing sounds with light motion," Mushtaq notes.

One link that has been found in research, however, is synesthesia and autism. In one 2020 study2, researchers note that there may be higher rates of synesthesia among diagnosed individuals with autism. "Up to 20% of autistic individuals may experience synesthesia, and more research is currently being conducted to understand the correlation between the two," Mushtaq says.

First, we'll break down a few common ways people experience synesthesia, though it's important to note synesthetes will experience their synesthesia differently, and may experience varied combinations of these signs. Then, we'll get into some other telltale characterizations.

On top of the way synesthesia presents for individuals, there are some other signs that indicate someone really is a synesthete. For one thing, with synesthesia, the sensory experiences are consistent (i.e., if the number seven "looks" green to a synesthete, it will always be green, even years later). Additionally, synesthesia happens unwillingly without having to control or even think about it.

And according to Winter, it's especially difficult to understand because it presents so differently among individuals. Some may experience synesthesia in a variety of ways, while some may only experience it one way, for example. "Whatever it is, it could be on a continuum or a spectrum," he says, adding that it's important to remember it is not a pathology.

For a quick test you can do yourself, the same principles apply. Try to recruit a friend to track your responses, or log them somewhere you won't look at them.

As Winter (who is not a synesthete) explains, "It's predictable, meaning that you're going to have the same response or associate the same thing, no matter what. If you asked me what 1,000 different words taste like, I can give you a taste. A week from now if you asked me those 1,000 words again in a different order, my taste might not be entirely consistent."

And while there is currently no treatment for synesthesia, there doesn't really need to be, as it's not a disease or disorder. For most synesthetes, in fact, the experience isn't a "bad" thing. For some people, it can even be advantageous, such as artists who can paint what a song looks like to them.

Our senses offer us a means to take in and experience the world around us, and for those with synesthesia, the world is a much more robust and colorful (literally) place. As more research is done to understand the phenomenon, the good news is, synesthesia is not a bad thing, and those who have it get a rare sensory experience that those who don't have it can only imagine.