The Many Colors of Synesthesia

Uncategorized — By on December 17, 2017 at 9:21 am

Article by Varun Athilat

Monday is yellow; Tuesday is quite a deep red; Wednesday is sort of a grass green; Thursday is a much darker green but still quite bright; Friday has always confused me, it’s either a very dark purple, blue or grey; Saturday is white; and Sunday is sort of a light peach color. For anyone who doesn’t understand what’s happening here, I have a neurological condition called synesthesia, which means that I ‘see’ words in colors.” 

–Stephanie Carswell (Australian actress)


Synesthesia is one of the most astounding phenomena in the world of psychology and has long been a study of interest for philosophers and scientists. While “seeing words in color” may seem like a bizarre concept to many, it is very artistic in its essence and is an uncanny ability that many talented musicians, artists and even scientists exhibit. Alessia Cara, Duke Ellington, and Sam Endicott are just a few well-known synesthetes. Simply put, synesthesia is the anomaly where the stimulation of one sense produces the sensation of another: For example, listening to a sound that vividly brings a color or array of colors to mind. My goal here is to take a closer look at synesthesia and the implications it brings to the world of art, cognition, and the evolution of the brain.

Synesthesia, derived from the Greek “syn” to mean “union” and “aesthesis” to mean sensation, has been put under a magnifying glass under philosophers, dating back to Greek antiquity and has taken on a huge role in the study of neuroscience in modernity. [2] While all humans can be thought to have some minor forms or levels of synesthesia, the much stronger cross-modal condition can apparently be found in around 1 in 23 people, constituting about 4.4% of the population. [3] This prevalence makes synesthesia an excellent anomaly for study in the realm of psychology. Synesthesia on this level is generally characterized by a vivid trigger or association of one sense brought on by the experience of a physical sense.

Dr. Vilayanur Ramachandran took it upon himself to investigate more minor forms of synesthesia, showing a random set of people on a beach in California a shape with many sharp edges and another, much more curvy shape, asking them “Which [shape] is a bouba and which one is a kiki?” [4] These, of course, are just nonsense words, but the general public, save for a few exceptions, seemed to agree that the curvier shape was a bouba and the sharper shape was a ki-ki. Dr. Ramachandran suggested that the way the words are pronounced – bouba being softer and rolling off the tongue easier than kiki, which is much harsher to say – correlates to the way someone perceives the shape, suggesting an inherent, nonarbitrary bias. Dr. Ramachandran goes on to say that this association can possibly be attributed to some bridging or adjacent placement between the motor areas for the hands and the mouth in the brain coupled with unconscious associations made between hand and mouth movements.

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Figure 1: “A” would be a kiki and “B” would be a bouba respectively. [5]

There are currently 54 known types of synesthesia that can be organized into five distinguishable categories. [6,7] Firstly, and the most common by far, is grapheme-color synesthesia. This is the association of colors with letters or numbers. Richard Cytowic, an American neurologist, has referenced this form of synesthesia in his book, “Wednesday Is Indigo Blue: Discovering the Brain of Synesthesia” where he shares the anecdote of a woman, Jean Milogav, who told her niece to choose “anything but Paul” as the name if she were to have a baby boy, because of how “gray and ugly” it is. [8] Then there is lexical-gustatory synesthesia, which is the association of flavors with sounds or words. Number form synesthesia is the three-dimensional visualization of numbers. There is research present that suggests that there is some underlying mechanism between synesthesia and the autism spectrum (the research is self-referenced as non-definitive, so take this with a grain of salt). [10] There is a known autistic savant by the name of Daniel Tammet, who makes connections between numbers and the goings-on in his daily life, on a level beyond what most people can conjure. [11] Tammet’s abilities were most noted in 2004, when he was able to recite the first 22,514 digits of pi, seemingly by the numbers just making themselves shown in his head. [12]

Figure 2: The 54 types of synesthesia. [6,7]

Then there is ordinal linguistic personification synesthesia, which is the connection between letters, numbers or days of the week and certain personality traits or emotions. For example, “Saturday” in a given month may seem gloomy or despondent or “Wednesday” may seem to exhibit a bouncy, happy-go-lucky aura. Finally, there is sound-color synesthesia, or the association between musical notes and colors. Isaac Newton, 17th-century physicist, toyed around with the idea of “colored hearing” and tried to tie threads between tones in music and tones of color. [13] There is a synesthete, Melissa McCracken, who has garnered some notoriety for constructing paintings out of the mental images she sees when listening to certain songs. [14,15]


Figure 3: Melissa McCracken’s painting of what she sees when listening to “Callow” by Airhead. [14]

The world of synesthesia leaves plenty to be learned of and discovered. The condition itself is rooted in the notion of making connections and associations. There is word being tossed around about the implications of learned synesthesia and the pursuance of it, and this in itself holds an abundance of questions and thought experiments to be explored: Can vivid synesthesia be learned? Does the presence of synesthesia say anything about the ability to classically condition someone – that is, to associate a desired stimulus with a null stimulus? What notable changes occur in the brain if someone were to acquire synesthesia? What changes are there already present in the neuroanatomy of someone with synesthesia? Is synesthesia different based on upbringing or the culture you grew up with? After all, a bouba to some people may be associated with the more jagged shape than the curvier shape for different reasons. What can synesthesia say about the unacknowledged biases that we have within us? Can the use of certain hallucinogenics induce or affect synesthesia? Perhaps we will explore these questions in a deeper context at a later time.

Synesthesia holds an infinite realm of possibilities and associations that can be made between seemingly anything that can affect the human experience. The condition is a testament to the unending ways the psyche proves to be one of the most astounding products birthed from the known universe, and it seems that the studies concerning synesthesia and its implications for a variety of different facets in day-to-day art, science, and discovery have only just begun.


  13. Peacock, Kenneth. “Instruments to Perform Color-Music: Two Centuries of Technological Experimentation,” Leonardo 21, No. 4 (1988) 397-406.


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