The author offers a few photos from her travels that show how she views the world.
When I was in second grade, my teacher assigned a math workbook page on addition and subtraction. I was on one of the last problems in the set: 2 + 2. An easy problem; I already knew the answer. What I didn’t know was why the twos were yellow and kind of bossy, and the answer, four, was sky blue and meek.
I became aware of a running commentary in my head the whole time I worked down the page: there was green three, a friend of two; mature and orange nine; and blue-gray six, a dependable athlete.
Why am I seeing these numbers like this? I wondered. Am I normal? Is everyone else seeing this, too?
I didn’t spend too much time thinking about it then or for a long time to come. Those math problems were the only things standing between me and free play that morning, and there was a book in the class library with my name on it.
Nearly 20 years later, my friend Will and I watched neuroscientist V.S. Ramachandran’s TED talk “3 ways of understanding your brain.” Toward the end of the presentation, Ramachandran said something that brought me right back to that second-grade classroom. He was describing synesthesia, a neurological condition documented in the 19th century by Francis Galton, the polymath cousin of Charles Darwin.
“[Galton] pointed out that certain people in the population who were otherwise completely normal had the following peculiarity: every time they see a number, it’s colored.”
That there was something peculiar about seeing colored numbers interested me. I glanced over at Will.
“Hey, you don’t see colors with numbers?”
Will laughed. “No, of course not.”
“Do you?” he asked.
I described briefly what I see in my mind when I interact with numbers and letters.
“Case, you definitely have synesthesia.”
And so I do.
The word synesthesia comes from the Greek “syn,” meaning union, and “aisthaesis,” meaning sensation. Ramachandran described synesthesia as a “mingling of the senses,” in which certain triggers activate more than one area of the brain.
Synesthetes have reported many types of the condition, including sound-smell, flavor-color, and vision-flavor. The most common form is grapheme-color, in which the synesthete experiences colored letters and numbers. However, there is no uniform synesthete experience, even among those who have the same type. A number that appears sky blue for one synesthete might be hunter green for another.
I have grapheme-color, time unit-color, and ordinal linguistic perception (OLP). This combination means that not only do numbers and letters (graphemes) and days of the week and months of the year (time units) have colors, but OLP gives them personalities as well, including genders. Monday is blue and a little glum; Tuesday is yellow and aggressive; Wednesday is orange and upbeat; Thursday is purplish-black and somewhat ominous; Friday is green and relaxed; Saturday is salmon-colored and happy; Sunday is gray and resigned.
Numbers are similar: The aforementioned two is bossy when she appears alongside other numbers, while five, also female, is red-rimmed with gold and something of a firebrand. If Cersei Lannister were a number, she’d be a five.
Although synesthesia has received increasing credibility as an area of study in recent years, there is no conclusive evidence for what causes synesthesia or why it manifests in unique ways for different people. Some researchers believe that some forms of synesthesia may be caused by atypical myelination.
Myelin is a material that insulates neurons and facilitates them making quick connections in different parts of the brain. Atypical myelination along certain neural pathways in the brains of some synesthetes “may allow for a difference in the extent of connections and the rate of feedforward and feedback in specific parts of the brain, creating perceptions that are usually inhibited by more common levels of connections and neuronal impulses,” according to Sean Day, president of the American Synesthesia Association. Other researchers have suggested that synesthesia is linked to early development and long-term memory, or that it may be more widely experienced in childhood but “lost” in most people as their brains develop toward adulthood.
Synesthesia is largely thought to be a genetic condition, and it is common to find several members of one family who have some synesthetic experience, though they might not be of the same type. In my own family, my father and younger brother both play guitar and see colors when they strum different chords. But they don’t see the same colors for the same chords, and I don’t see colors with sound at all.
Patricia Lynne Duffy, author of Blue Cats and Chartreuse Kittens: How Synesthetes Color Their Worlds, is the only person in her immediate family to have synesthetic experiences. She realized she had a distinct way of seeing the world at age 16, when she referenced the colors of the letters P (yellow) and R (orange) to her father, who didn’t know what she was talking about. “It made me realize maybe we all have some quirk of perception that makes us see the world in a different way,” Duffy says.
Genetics seem a vital component for understanding the causes of synesthesia, and a team of international researchers began a project in summer 2012 that they hope will shed some light; it’s particularly focused on the common grapheme-color connections.
Duncan Carmichael at the University of Edinburgh, one of the project’s researchers, says it seems unlikely that a single gene is responsible for the development of synesthesia. “The initial studies in this area have identified some areas of interest on several chromosomes, but those areas contain a lot of genes that may or may not be involved,” he says.
“Research into the genetics of synesthesia is really in its infancy,” Carmichael notes. “While it certainly appears as if synesthesia is a phenomenon with a strong genetic component to it, the mechanism of inheritance and which genes contribute to the development of synesthesia are currently unknown.”
Like a lot of misunderstood conditions, synesthesia hasn’t always been taken seriously. For decades, neuroscientists and researchers scoffed at synesthesia, dismissing those who claimed to have synesthetic experiences as attention-seeking kooks and exhibitionists.
In the book Wednesday Is Indigo Blue: Discovering the Brain of Synesthesia, Dr. Richard Cytowic describes the cynicism with which his professional interest in synesthesia was met in 1980. Cytowic’s colleagues called the condition “too weird, too New Age,” and rejected it as an authentic experience because it “contradicted standard notions of separate sensory channels in the brain.”
Indeed, synesthesia can be difficult to categorize. It is not a disease or disorder, nor are synesthetic experiences hallucinations. Synesthesia is not a conscious conjuring of visualizations or recollection of tastes and scents.
The use of functional MRI (fMRI), which measures blood flow in the brain, has since proven that the brain activity that occurs during a reported synesthetic experience does in fact differ from what happens during a voluntary visualization. Studies indicate that individuals who have colored hearing or colored graphemes show activation in the v4 and v8 areas of the brain — which are associated with color perception in the human visual cortex — when stimulated by sounds or graphemes. This phenomenon did not occur in control subjects.
There is no uniform synesthetic experience. Everyone’s perceptions take on their own appearances or sensations and occur involuntarily. In Wednesday Is Indigo Blue, Cytowic and co-author David Eagleman describe it this way:
When a synesthete sees a six printed in black ink, she knows it is black and sees it as black, but she also has the experience of greenness. The experience of green is automatic and involuntary.
If I think about the year 2013, or any year, I see a large ring made up of 12 long rectangles that connect end to end in a closed loop. My most positive associations are with April, pink and cheerful but pragmatic; July, orange and fun-loving; and October, which is half-brown/half-black and appears ominous, but is actually quite warm and wise beneath the surface.
My strongest memories of synesthetic experiences from when I was younger come from my math classes. The personality-ascribing OLP aspect of my synesthesia usually influenced what I enjoyed and what felt like drudgery. I loved graphing problems because I liked the interplay between the x and y axes. X is straitlaced and organized, a guy who gets things done. Y is more easygoing, laid back, comfortable with a little disarray. X is Felix Unger to Y’s Oscar Madison. But working with numbers in straightforward algebraic equations sometimes left me feeling irritated and a little cranky after long periods of time.
Unlike some synesthetes, I don’t project these colors or the wreath-like shape of each year into the world around me, but instead see them in my mind’s eye. The personality descriptions are also instant and involuntary. I’ve spent no time concocting elaborate character sketches for the months; these are the words that immediately come to mind when describing these personas.
Some synesthetes experience flavors when hearing a person’s name, or a tactile sensation sparked by a sound. Others see colors when listening to music, having an orgasm, or tasting food.
For Sean Day, the taste of coffee triggers a blob the size of a dinner plate, with a color that resembles McIlhenny’s green Tabasco sauce.
Someone who has never been able to taste the rainbow (without eating Skittles), seen a salmon-colored Saturday, or had a non-hallucinogenic visual of music in motion might assume that this involuntary cross-talk is an annoyance and a distraction. Aeon magazine reported that people who have mirror-touch synesthesia, through which they perceive another person’s physical experience and then feel those same sensations because of triggers in their own brain, sometimes feel overwhelmed or overloaded by their perceptions.
For my part, I am rarely distracted by my synesthesia. If I’m working with numbers or repetitive words or letters for a long period of time, I’ll sometimes become more aware of the colors and personalities. But even then, it’s usually a fleeting awareness, and I spend no more than a minute or two contemplating it before returning to whatever else I’m doing.
Many synesthetes say that they wouldn’t give it up even if they could, and I am of that same mind-set. To lose those vibrant purples, reds, greens, and blues — and the personalities that claim them — would surely dim my perception of the world.
Realizing I have synesthesia gave me a new appreciation of my own brain and how I learn and process information. If anything, I regret that I didn’t more fully explore and appreciate my multicolored and moody numeric perceptions sooner.
Photos by the author.
Casey Hynes is a freelance journalist based in Asia. She has lived in South Korea, China, and Thailand and travels throughout the region. She is a 2008 graduate of the Columbia Journalism School, and her work has appeared in The Wall Street Journal, Vogue India, and a number of regional publications.