Imagine seeing a clock, and then tasting blackberries, or hearing a trombone, then feeling a tickle in your right ear. Imagine being completely convinced that Thursdays are a deep navy blue. All of these experiences are symptoms of synesthesia.
Synesthesia is defined as simultaneously perceiving two or more senses. The most common form occurs when when someone always sees a certain color in response to a certain letter of the alphabet or number.
According to Richard Cytowic, MD, there are five synesthetic perceptions: involuntary, projected, durable and generic, memorable, and emotional.
“Synesthetes do not actively think about their perceptions; they just happen. Rather than experiencing something in the “mind’s eye,” as might happen when you are asked to imagine a color, a synesthete often actually sees a color projected outside of the body,” states faculty.washington.edu.
Symptoms of synesthesia aren’t as rare as one might think. Associating an emotion with a song is a synesthetic experience. Thinking of hot cocoa when someone mentions winter is another mild example of synesthesia.
“What makes strange phenomena like synesthesia all the more fascinating is that they raise unsettling questions about some of the most fundamental givens of the “normal” brain: Does color even exist, or is it merely a product of our fancy?” questions brainpickings.org. “Are life’s sensory qualities static and permanent — is the sky always blue, lemons always sour — or are they fluid and dynamic attributes on a spectrum we just happen to experience arbitrary slices of?”