Psychology Today describes synesthesia as "a neurological condition in which stimulation of one sensory or cognitive pathway (for example, hearing) leads to automatic, involuntary experiences in a second sensory or cognitive pathway (such as vision)." Experts theorize that there may be up to 80 types of synesthesia, including the perception of time as a 3-D entity and the association of alphabetical characters with colors, sounds, and even genders. Barring severe brain trauma, synesthesia is usually congenital, and appears to be partly genetic.
A childhood friend of mine has chromesthesia, which allows her to perceive sounds as intricate swirls of color in her mind's eye. Her unique experience of the world fascinates me, and in 2015 I created this series based on my research and her testimony.