Ashley Hoffman | Associate Editor of Natural Science
Synesthesia is a rather curious condition. While many have not heard of it, looking deeper reveals that synesthesia may be more common than we expect. About four percent of the population is predicted to experience some form of synesthesia in daily life, from lexical-gustatory (tasting words) to grapheme-type (hearing colors). This is excluding the speculated 1:300 ratio of individuals who experience some occasional form of synesthesia, such as hypnosis or a drug-induced, psychedelic synesthetic experience. Despite its high prevalence, the condition remains a mystery to neuroscientists and psychologists alike.
Pioneering researcher Dr. Lawrence Marks, Professor Emeritus at Yale University, describes how synesthesia plays a crucial role in understanding relationships between psychology and neurology, thereby opening doors to new areas of hybrid research. His novel The Unity of the Senses delves into the psychological, literary, and scientific history that outlines synesthesia over the decades. For Marks, it was a serendipitous path that drew him to study this condition, which occurs at a rather unique crossroads between sensory perception and language. When I reached out to discuss his research, he described learning of synesthesia when a colleague in graduate school gave a seminar on the condition. Marks admitted he found synesthesia “exceptionally odd” and did no more than make a “mental note” of it. Later in the course of his research on sensory perception in the 1980s, however, he realized there had to be more than just one way to perceive things — that there must be more than just what our eyes see that can influence our view of the world. Hence, synesthesia came to play a critical role in his understanding of this interconnected perspective of the world. The abnormal sensory qualia associated with synesthesia parallelled the analogies he studied in 19th century English and French poetry (such as Keats, Shelley, and Baudelaire) and their use of the “synesthetic metaphor.”
The nature of synesthesia carries a certain mystery. The fine arts world has mingled with synesthesia for some time; this modality of the senses is the reason why Kandinsky titles his artworks with musical references such as fragment and composition and why Kanye calls the sound of a piano blue and sees basslines in dark browns. Despite this allure, research on synesthesia is fairly limited. As Dr. Marks describes, there are periods of research — droughts — when there is simply not enough funding available for research focused solely on synesthesia.
Consequently, many interested researchers, including Marks himself, must pursue it alongside other projects. Completing a quick Google search of “what is synesthesia” yields the same few articles scattered throughout the years 2010 – 2013 — a clear indication that the field of synesthesia research is in desperate need of revival.
This past April, however, a potential breakthrough study closely related to synesthesia was published in the journal Consciousness and Cognition, proposing that everyone possesses a latent form of synesthesia. This harkens back to the speculation that about one in three hundred individuals can experience a mild or induced form of the condition. The study, led by Dr. David Brang at the University of Michigan Ann-Arbor, involved synesthetes and non-synesthetes alike by recording novel patterns in conscious visual responses in “the mind’s eye” to sound (such as white flashes when a door closes).
This study is especially exciting as it exemplifies a new form of synesthesia research that explores the condition through a novel neurological angle in addition to the previously studied psychological perspective. Brang’s results bring fresh information to the table and propose that there may be a common form of synesthesia consistent among the general population. While we may not all readily see music or words in a myriad of shades, given the proper stimuli, we can likely experience something similar. One can only imagine the implications of being able to quantify synesthesia into degrees of sensory perception or discovering a genetic basis to the condition and its manifestations.
Over the years, I have continued to be surprised at what little is known about the various types of synesthesia, despite the promise shown by the work of scientists such as Dr. Lawrence Marks and Dr. David Brang. Nonetheless, there is potential for more synesthesia-focused research to come into fruition, especially in light of Dr. Brang’s novel findings.
A substantial amount of this passion for synesthesia research arises from personal experience. I experience grapheme-type synesthesia, where numbers, letters, and names have colors and textures. It’s fascinating to meet others with synesthesia and have conversations about our unique experiences with these interconnected sense modalities. At the heart of our discussion, however, lie so many unanswered questions: Why do some associate names with seemingly random tastes such as chocolate? Why is Wednesday two feet to the left and Saturday right behind me? How come the letter “P” is a fuzzy lavender for me, but bright red to someone else? All of these disparate questions encapsulate the synesthetic experience and may one day be answered.
Side note: If you’re curious to know if you have a form of synesthesia, check out Dr. David Eagleman’s synesthesia battery test. It’s a common occurrence for individuals with synesthesia to live a majority of their life without knowing they have it! Dr. Eagleman has studied various neurological conditions, most notably synesthesia, for many years and has published an award-winning book Wednesday is Indigo Blue, which provides an excellent overview.