An accessible, concise primer on the neurological trait of synesthesia—vividly felt sensory couplings—by a founder of the field.
One in twenty-three people carry the genes for the synesthesia. Not a disorder but a neurological trait—like perfect pitch—synesthesia creates vividly felt cross-sensory couplings. A synesthete might hear a voice and at the same time see it as a color or shape, taste its distinctive flavor, or feel it as a physical touch. In this volume in the MIT Press Essential Knowledge series, Richard Cytowic, the expert who returned synesthesia to mainstream science after decades of oblivion, offers a concise, accessible primer on this fascinating human experience.
Cytowic explains that synesthesia's most frequent manifestation is seeing days of the week as colored, followed by sensing letters, numerals, and punctuation marks in different hues even when printed in black. Other manifestations include tasting food in shapes, seeing music in moving colors, and mapping numbers and other sequences spatially. One synesthete declares, “Chocolate smells pink and sparkly”; another invents a dish (chicken, vanilla ice cream, and orange juice concentrate) that tastes intensely blue. Cytowic, who in the 1980s revived scientific interest in synesthesia, sees it now understood as a spectrum, an umbrella term that covers five clusters of outwardly felt couplings that can occur via several pathways. Yet synesthetic or not, each brain uniquely filters what it perceives. Cytowic reminds us that each individual's perspective on the world is thoroughly subjective.
Richard E. Cytowic, MD, MFA is a neurologist best know for bringing synesthesia back into the scientific mainstream in 1980. The trait of crossed senses is now seen as important to understanding how brains perceive.
Wednesday Is Indigo Blue: Discovering the Brain of Synesthesia (with David Eagleman) won the 2011 Montaigne Medal.
Cytowic also writes non-fiction and fiction, and received his MFA in creative writing from American University. The Pulitzer nominee's work has appeared in The Washingtonian, New Scientist, and the New York Times Magazine.
This is a really nice introduction to the subject. As a person who has synesthesia, this is a great reference to know if you want to explain what the phenomena is like. One of the major difficulties as a person who has this is understanding what it's like to NOT have it. This book helps a lot. It also helps separate different kinds of synesthesia in a way that is enlightening.
Being someone who has SSS and "colored hearing" (which apparently is kind of rare since SSS is a category that doesn't seem to cross over to other areas), this helped explain to me so many of my life choices and linguistic claims that might have seemed odd to socially claim otherwise, but made total sense to me.
I highly recommend this book to anyone who thinks maybe they have synesthesia, or want to understand a phenomena that is not immediately material, but is never the less, scientifically sound.
Wish I read this one way earlier. I’m not saying I now understand everything about the life of syntesthetes but I understand a little bit more where some people are coming from.
It’s also a nice introduction & eye-opener that everyone, and I mean EVERYONE, experiences the surrounding world very differently.
A fun, unique introduction that reveals the "new" science of synesthesia. Synesthesia as a phenomenon is not entirely new, but was for a large part of its history a largely rejected field within psychology. Now, as Cytowic illustrates, the phenomenon is more than just "seeing colors," and can reach into various emotional states. In fact, Cytowic focuses mainly on synesthesia, but also broadly covers perceptual concerns and eccentricities.
Some fun facts on synesthesia from this book: - Left brain (more analytical) is associated with synesthesia effects, which defeats the misconception that the right brain (more creative) is associated with synesthesia. - Famous physicist Richard Feynman saw colors in the floating equations he witnessed, literally imagine seeing floating Bessel equations and tan functions in light-tan (guess that makes physics a lot easier?). - Meditation is more likely to lead to synesthesia, rather than hallucinogenic drugs, contrary to standard misconceptions that drugs such as LSD could induce synesthetic experiences. - Individuals who know complicated languages are more likely to have synesthesia. English speakers, for instance, are more likely to have synesthesia since English has so many exceptions in its spelling and use. Japanese speakers though, with the many characters they memorize as part of the language, are even more likely to be synesthetes.
Overall, this is a really cool text that introduces the subject in a multifaceted manner. I also appreciate the author's many references to unique synesthesias, he is clearly an expert in the field. The book is also unique amongst MIT Press books in that it features "color plates," these are small insets in the middle of the book that are in-color diagrams of various synesthesia experiments or phenomena, such as "colored numbers," Retinex Mondrian experiments, and theories explaining how synesthesia develops. These color plates really add to the reading experience of the book itself.
My main gripe with the text is the punctuation errors as mentioned in other reviews, the book seems a little rushed towards the end. The organization of the topics in the book is also very disorganized, the author lacks a flow in sequencing the story of synesthesia, and the book at times just feels like a smorgasbord of weird synesthesia-driven effects. Along with that, I wish the author provided a bit more context to different parts of the brain and what they do, I have some neuroscience background but it has been a loooooong time since I learned what the thalamus does, and this background could be more helpful for readers who are looking for a broad intro into neuroscience-based books. Despite these shortcomings, this is a lovely introduction, and a really colorful text both visually and mentally.
⭐⭐⭐⭐ (4/5) I can’t remember a time when color wasn’t more than just something I saw—it was something I felt. From an early age, I could sense the subtlest shifts in hue, feeling the difference between shades others would call identical. Color wasn’t just visual for me; it carried emotion, depth, and even sensation. But I never had the words to explain this experience—until I read Synesthesia by Richard E. Cytowic.
For the past eight years, I’ve lived with Idiopathic Intracranial Hypertension, a condition that has altered the way my brain processes sensory input. While I’ve always experienced a strong interplay between color, sound, and emotion, the boundaries between my senses have blurred even further since my diagnosis. Yet, for most of my life, I assumed this was simply part of being me—something I never questioned.
I had heard of synesthesia before, but my understanding of it was surface-level—I thought it was just seeing colors when hearing music or associating numbers with specific hues. But Synesthesia shattered that narrow perception. Cytowic reveals the vast and varied ways synesthesia manifests, from people who "taste" words to those who "see" time as a physical shape. Suddenly, many of my own lifelong experiences made sense in a new light.
One of the most profound realizations this book brought me was how my connection to color has shaped my life. I never just saw colors—I felt them. I instinctively knew how to mix and match shades, not just by sight but by how they resonated with me emotionally. Whether it was crayons, paints, or eyeshadows, I could recreate a color with uncanny accuracy based purely on how it made me feel.
That moment in middle school stuck with me. I didn’t just enjoy working with color—I understood it in a way that felt instinctual. Years later, that realization became the foundation of my career in professional makeup artistry, where my ability to manipulate color became my signature skill. Eventually, it led me to create a custom lip color brand, which turned into a highly successful business. I had always assumed I simply had an eye for color—but Synesthesia helped me understand that my experience runs much deeper.
Cytowic’s writing is both accessible and engaging, weaving together neuroscience, case studies, and historical context in a way that never feels dense. He breaks down the science of synesthesia with clarity, making the book an excellent primer for those new to the topic. However, while Cytowic excels at explaining the science, I found myself craving a deeper dive into the emotional and memory-based aspects of synesthesia. These connections feel central to the experience, yet they weren’t explored as fully as I’d hoped.
For me, Synesthesia was more than just an academic exploration—it was validation. What I once thought was just me being different turned out to be a shared phenomenon among synesthetes worldwide.
If you’ve ever felt like your senses don’t quite operate the way others say they should, or if you’re simply fascinated by the hidden complexities of perception, Synesthesia is a must-read. It doesn’t just explain a neurological condition—it reveals a world where the senses intertwine in ways most people never imagine. For some of us, that world isn’t just fascinating—it’s home.
If you're intrigued by, or have, synesthesia, Cytowic's books are the way to go. This book is basically a pocket version of his other writings, but still packed with information nonetheless. He is certainly the medical expert in this area, and I continue to gobble up his work to feed my own curiosity.
Some of my favorite passages from the book:
"Not everyone sees the world the same because each brain individually filters and distills the universe in its own unique way."
"As each brain develops over time in its particular context, it constructs a person who has never existed before and will never exist again."
"Metaphor reveals the similar in the dissimilar, and without synesthesia preceding language developmentally, we wouldn't be able to understand metaphors like "loud tie," "warm color," or "sweet person."
Synesthesia, the experiencing one of your senses through another. for example you read the word "street" and smell citrus. to me it's intriguing bc it's something that is hard to prove it's real or even study it. it's a first person experience. it's automatic, involuntary and perceptual. it just further proves that everyone sees the world differently. every brain filters the world in its own way. It tends to be genetic and allows for a further look into how nature interacts with nurture. Synesthesics tends to also be more in tune with their emotions and feelings making them extremely empathic. They are also more likely to be able to read auras because of this.
Having never noticed the concept of synesthesia before, I found this an excellent introduction, with engaging writing and enough detail to answer the questions that I came up with while listening to this audiobook. The author describes the different ways this trait manifests itself in different people and identifies some of the causes. He also conjectures people in history who exhibited this trait based on their writings or writings about them. Just the right length for an introduction to the topic…
Interesting but kind of dry and hard to follow. I’m satisfied just knowing a bit of the way certain neurotypes experience the world, but this tried so hard to definitively describe the experience of being synesthete that it was kind of alienating when it would regularly note that it is practically impossible to understand it from the outside. By being very scientific and study-based in nature, that just added to the inaccessibility of the material as someone who doesn’t experience synesthesia. I did DNF at about 80% because I was getting bored and no longer absorbing anything from it.
The definitive examination of synesthesia by the neurologist who brought it into mainstream scientific study. I'm revisiting this after reading it in the 90's as a doctoral student studying perception. This edition includes a number of updates but still does a great job of exploring the phenomenon of unified sensory experience. Don't let some of the jargon get in the way of the richness of real life examples Cytowic recounts in the book.
Easy to read intro to research on synaesthesia. An emotional experience for anyone with synaesthesia, as there are plenty of descriptions of other synaesthetics' mappings, which may agree or disagree with one's own.
Super interesting! It was so cool reading about the science behind Synesthesia and seeing myself in some of the things he was talking about, and getting to put a name to what I experience. The information was explained in a very easy-to-understand way as well.
Compared to other books in the MIT Essential Knowledge series, I found this one was a bit more technical and less accessible, it had interesting elements and was informative, but overall it felt more like coursework than reading.
First nine chapters or so are excellent. The material itself is interesting, the writing is clear, and it’s fun to dive into an experience so divorced from one’s own. The last two chapters seem unedited. Multiple typos and much more unexplained academic jargon than in the rest of the book.
A thorough and extremely interesting account of synesthesia. A bit too technically detailed in places for this type of book. But still readable. A nice focus on that deepest of questions - the mapping from neural electrochemical events to subjective experience and action. Cross channel effects reminding us of the complexity and the mystery of the process and maybe providing useful methods and insights. And if you want to experience it for yourself in one or more of its forms the author suggests sensory deprivation and/or meditation rather than the shotgun approach of attempted chemical enhancement.
Definitive book on the subject by its foremost pioneer.
I first learned of the trait in the 1990s, during the decade of the brain but thought Cytowic was a researcher from the late 1800s. What a pleasant surprise to discover he had written several books on the subject and was still very much alive.