🍄 Synesthesia: The show of a lifetime.

Synesthetes can taste words and see sound such as music. Neuroscientists now sense that these experiences could feed into a better understanding of our mind-body and brain-connectivity.

Feb 02, 2024

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Hello, we’re Alice and we are always in a state of wander. Does two plus two equal yellow and certain letters make you emotional? This could make you a synesthete, experiencing synesthesia. ‘Everybody knows the word "anesthesia," which means no sensation,’ neurologist Richard Cytowic, author of The Man Who Tasted Shapes tells ALICE. ‘Synesthesia means joined sensation, where two or more of the senses are hooked together. So that my voice, for example, is not only something that they hear but also something that they see or taste or touch.’ Essentially, senses that are normally separate blend together.

A tale of two senses

‘Synesthesia is a neurological condition, sometimes called the cross-wiring of senses, where a stimulant of one sense — touch, taste, sound, sight — causes the experience of another,’ explains journalist Imogen Malpas — who has synesthesia, and a master’s degree in medical anthropology from the University of Oxford — in her 2020 TedX Oxford conference talk explains.

‘Synesthesia is, for all of us, extremely fascinating in so far as it is the mixture of senses, a coupling of senses, which normally are not experienced,’ the late Professor Hinderk Emrich, director of the department of Psychiatry, Social Psychiatry and Psychotherapy at The University of Hanover Medical School told ALICE. ‘That means you experience something, for example, a tone or a pattern or a touch or a taste or a smell, and you have a combined completely different sensation. By looking into these wonderful persons with synesthesia we can increase coherence of mind in the combination of mind and feeling, mind and body, mind and outer reality of persons to persons — these are all types of bridges.’

Synesthesia may have taken off on TikTok — #Synesthesia and #SynesthesiaTok have 553.4 million+ and 42.7 million+ views respectively — but it’s a real biological condition. ‘It runs in families although the particular associations don’t necessarily, so for instance, somebody who experiences synesthetic taste may have family members who experience synesthetic color,’ says Professor Jamie Ward, director of Neuroscience at the University of Sussex during his TED Talk. ‘So it’s a general disposition here. And we know that there is a genetic basis to synesthesia through the studies of the genome, although we don’t fully understand what these genes are doing.’

This blending of senses is basically a human bonus — an added extra. ‘Synesthetes don’t just differ by having unusual experiences, they’ve got better memory, they’re more likely to go into certain types of occupations and jobs like creative industries,’ Ward — who is president of the British Association of Cognitive Neuroscience — tells the BrainCast podcast. ‘When we asks synesthetes what are your strengths and weaknesses there are certain things that come out, like being better at memory and learning languages. They are also very good at perceptual discrimination so spotting things that other people don’t notice. We don’t find many weaknesses.’ Ward’s Sussex Neuroscience department has studied 100 brain scans of people with synesthesia. ‘It’s about understanding more broadly how individual differences, and how people think and behave, map onto the brain.’

Think outside the box

‘It is very difficult for mathematicians to cope with the problem: how can I visualize the four-dimensional or five-dimensional space?’ Emrich told ALICE. ‘And synesthetes, since they live in a hyper-reality — a more complex reality — could internally represent more complex realities. So possibly synesthesia is a mode of cognitional evolution of mind. This is a speculation, we don't know it, but in some regards synesthetes are higher, they have a more pronounced capacity of memorizing and they have very often, mathematical abilities. And they can visualize complex realities so it is possible that synesthesia is one mode of the evolution of senses.’

So what exactly is synesthesia?

There are at least 150 forms of synesthesia but Cytowic — credited with returning synesthesia to mainstream science in the ‘80’s after decades of obscurity — told ALICE that the most common form is colored letters and numbers. ‘That is, joining color to integers. This accounts for about two-thirds of cases.’

Recent research by the University of Sussex’s Multisense Synaesthesia Lab says 4.4 percent of the population have synesthesia. ‘The suspicion is that actually it’s pretty commonplace,’ neuroscientist John Harrison, author of Synaesthesia: The Strangest Thing, tells Wired. Harrison says that when he first met synesthetes four decades ago, they were reluctant to talk about their condition and feared ridicule. ‘That seems to have changed,’ he says. ‘Now it’s a very sexy thing to be a synesthete.’

And while the genetic link is still more suggestive than proven, Ward says that ‘it would be hard to think of an obvious environmental account within the family that would give rise to the association.’

The biology of a synesthete’s brain

‘[Genes] are almost certainly affecting the way that the brain matures, because synesthetes have differences in their brain, both in terms of gray matter — they’ve got more gray matter density, in say, parts of the brain to do with seeing,’ says Ward in his TED Talk:

“So parts of the brain seeing color, they have more of this, and similarly with regards to connectivity, they have more white matter connectivity between different regions of the brain. So they might for instance, connect the auditory parts of the brain with the visual parts of the brain, in a way that other people don’t normally. One suggestion is that we’re all born with synesthesia and most people lose it as part of the normal maturation process. But synesthetes, due to their different genetic composition, retain these roots that link together the senses.’’

Grapheme-colour synesthesia

‘Grapheme-colour synesthesia is where graphemes (letters and numbers) have colors. Whilst these colors might differ between individuals, for the individuals themselves, they remain themselves throughout their life,’ says Malpas. ‘These are the hallmarks of synesthesia and these need to be present in order for synesthesia of any kind to be diagnosed. The synesthetic experience must be involuntary, so it happens whether you like it or not. And it must be consistent; it remains the same throughout your life. It must be unidirectional, which means that graphemes evoke colors, but colors don’t evoke graphemes. And it must be automatic, so it happens completely without effort.’ (Temporary synesthesia can be caused by temporal lobe epilepsy, head trauma and meditation, or taking psychoactive drugs such as LSD and psilocybin.)

Paint me a picture, what would you see?

‘As you look at black text on a screen, you might see either a colored copy in your mind’s eye or you might literally project on the screen, that you’re seeing that they’re black but there’s a light shining through it,’ Ward tells BrainCast. Cytowic writes that around 40 per cent of the time, “a” tends to be red while in about 20 per cent of synesthetic couplings “h” and “s” are green, and “o” and “i” are often white or black.

Colored hearing

‘The next big group would be sight and sound synesthesia, or what is called colored hearing,’ Cytowic tells ALICE. ‘In this, voices, music, environmental sounds will make people see colored photisms … these are shapes that arise, they change and metamorphose a little bit and fade away. Think of it as a little bit like fireworks. So they have a location and space they move around. And they enjoy it very much. There’s a great feeling. There is almost a eureka sensation with this.’

The tip of my tongue

‘Color for music is a bit more how you would imagine if you had to paint trippy fireworks — pops, bangs, lines and so on — a beautiful kaleidoscope reaction,’ Ward tells BrainCast. ‘But you can have it in other senses, so one of the first cases I came across — my Oliver Sachs-type discovery — is a man who can taste words. As you speak to him its like an ever-flow of flavors that are on his tongue.’ Lexical-gustatory synesthesia, where someone can taste words, is estimated to occur in less than 0.2 percent of the population.

Time-space synesthesia

‘What if I had said, what shape is next week?’ Malpas says in her TEDX Talk. ‘For one per cent of you in the audience this should still make perfect sense, because this is what’s known as time-space synesthesia. For people with time-space synesthesia, time itself has a form, and this form takes physical shape around the person. And sometimes this form looks like a hula-hoop, or like a roller coaster, moving through and around the body. Sometimes it looks more like a halo encircling the head, and moving as the head moves, or not, depending on the person.

Malpas speaks about the science writer Alison Motluk describing her synesthesia as if she herself was riding a roller coaster, ‘starting off in January before moving down all the way through spring and summer, and then coming back up through autumn and winter to finish again in January.’ While the writer, Emma Yeomans, has “horizontally-oriented synesthesia.” ‘So on a typical working day for her she sits firmly in the present on her laptop, whilst to her right tea steams into her past, and to her left, papers and notes cover her future. In both cases the person remains at the center of the synesthetic form.’

Culture shift

Malpas suggests that cultural variations in the way we experience time can help us understand one another across borders. ‘The Pormpuraawan are an Indigenous Aboriginal community in Australia, and if you ask a Pormpuraawan individual to order photos of a person aging in order from the youngest to the eldest, they will invariably put the oldest photos of the person on the west, and the youngest photos to the east,’ she says. ‘So for the Pormpuraawan, time itself runs from east to west. And for the Aymara of the Andes, time runs along a similar axis as it does for us, but its reversed. So the Aymara logic is well, we’ve experienced the past – we know it, we’ve seen it – so it should lie in front, where we can look at it, whilst the future, which remains unknown, lies behind us.’

What implication does this have for synaesthesia?

‘Western time-space synesthete’s forms look a lot like clocks or calendars,’ says Malpas. ‘They usually run in clockwise or calendrical format around a circle. But what might these forms look like for time-space synesthetes growing up among the Aymara in a world without access to Western technology?’ As culture changes, she says, so does synesthesia. ‘It’s conceivable, even probable that people growing up in a culture without Western influence would display a completely different time-space synesthetic form to those that we see today in our research. Perhaps even one that doesn’t focus on the body but one that focuses on the landscape, which as far as we know, has never been seen. And the likelihood is that in focusing all of our attention on Western accounts of synesthesia, we’re missing out on an extraordinary range of cultural and synesthetic variation that is only paralleled by the extraordinary range of humans on this planet.’

The ideal future

‘Getting to grips with this idea of synesthetic continuum and its amazing variety, could help us to better grasp how different areas of the brain develop and work together,’ says Malpas. ‘Research into brain connectivity has helped us understand so much from sleep to addiction to memory, but we still have a lot further to go. I think launching a dedicated expedition to the furthest lengths of this synesthetic continuum could help us reveal vital information about the remaining mysteries of cognitive function. For example, synesthesia reveals unexpected connections between different areas of the brain, so it could easily be used to help understand how cognitive decline works, and maybe to even prevent it, or to help patients recover from traumatic brain injury.’

Ward wants to make use of big data banks full of genetic material. ‘But it’s being able to ask the right questions around finding new ways of exploring how different people see the world,’ he tells BrainCast. ‘Whether some people sort of update their predictions a lot more than they see things as they really are, versus being biased by your own history and your own expectation. Whether there are these kinds of styles and whether these styles kind of map on to, I suppose more classic conditions, like autism and schizophrenia and so on, and having a more modern twist on that. Those are the big science questions that excite me.’

What else we are wandering...

🔍 Original synesthesia
‘I think the real challenge for the future development, the technological development of the senses would be to look at the kinds of practices that one finds in place in other societies and start modelling or emulating them,’ says anthropologist David Howes in conversation with cultural historian Constance Classen and ALICE. ‘You give the example of the Desana of Columbia who understand the brain on the model of a kind of honeycomb. ‘Right,’ says Classen. ‘They have these marvelous multi-sensory images of the brain. It can be a humming beehive. In each little hexagonal container, there's honey of a different flavor, texture, odor, color, can be a swarm of multi-colored fish, can be fluttering butterflies. These really powerful and sensuous images of the brain. And they actually have a good amount of knowledge of the brain that are very different from any idea that we might have of the brain which is probably a picture in a textbook or, if you're a surgeon, your visual impression of what the brain looks like. But none of this rich sensory symbolism, which in some ways might be closer to how the brain works, and to how we experience those functions than those purely visual images would be.’

🔍 More perks of being a synesthete
Synesthetes are in a league of their own. ‘Synesthesia itself isn’t just having colors for letters and numbers,’ says Ward. ‘Synesthetes think differently, so they have stronger mental imagery. If I ask you to think about a bonfire, or touching fur, people differ in their ability to do this but synesthetes are very good at doing this. They have other traits like they are good at spotting certain attention to detail. If you ask them to think of creative uses of a brick or a coat hanger they do objectively better on these things.’

🔍 We can all get a little emotional
Why does scent make us so nostalgic? ‘From a neurological perspective, the part of the brain where emotion is processed literally evolved from the olfactory bulb,’ Rachel Herz, Professor of Psychology, Brown University tells ALICE. ‘So that smell is literally the pre-generator for emotion, neurologically speaking. That from a neuro-evolutionary, as well as, I think, a functional-evolutionary perspective, I think smell and emotion are essentially the same thing — in that emotion for us, the higher, primate complex brain, is the abstracted version of the same information that smell gives you.’

🔍 Sensory deprivation
And, cut! ‘When the normal inputs, external inputs to the brain are turned off, all sorts of interesting things happen,’ Cytowic tells ALICE. ‘We see this in the elderly, they don't see too well, they don't feel too well, they start having tactile visual hallucinations. They see things like the form constants, like synesthesia shapes that change and metamorphose in kaleidoscopic transformation. These same kinds of things happen in flotation tanks.’ The Ganzfeld effect, or, “the prisoner’s cinema” happens when your brain is starved of visual stimulation and fills in the blanks on its own. It has been experienced by miners trapped in the dark underground, and polar explorers, writes biologist Ashley Ward in The Guardian. ‘In ancient Greece, there are records of philosophers descending into caves to induce these hallucinations, in the hope of gaining insight. Given time, the light show can sometimes develop into more fantastical waking dreams. Underlying all of this is the brain’s frantic efforts to build its internal model, even though the sensory information it needs to construct that model has been cut off. The results are odd, though to some they can feel disturbingly real.’

🔍 Contemporary Synesthesia Artists:
Missouri-based artist Melissa McCracken translates the sounds she hears into vibrant splashes of color on canvas. Her vivid oil paintings are inspired by certain songs, showcasing how she sees musical notes as different textures and hues. Northern Irish artist Jack Coulter has a rare gift: he can see sounds. He uses his synesthesia experiences to inform his abstract expressionist paintings, each of which is full of vivid brushstrokes.
Amsterdam-based artist Daniel Mullen explores the sensory phenomenon with an ongoing painting series titled Synesthesia.

🔍 The Synesthesia Coloring Book:
What color is the letter A? If you answered with a color, you may have Synesthesia. People who “see” or associate letters and numbers with specific colors have Grapheme-Color Synesthesia. This coloring book is for you!

🔍 Synesthesia Meditation
Re-activate, sharpen and blend your senses with sensory mindfulness. Synesthesia Meditation is a guided meditation App to open your sensory channels.

🔍 Synesthesia by Richard E. Cytowic
From MIT Press: ‘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. Cytowic reminds us that each individual's perspective on the world is thoroughly subjective.’

🔍 What Color Is Your Name? A Synesthesia Project by Bernadette Sheridan
Does your name match your personality? It might, depending on the Synesthesia colors of your name. Visit Bernadette Sheridan’s site to learn more and, if you are curious, enter your name to see what colors are associated through her grapheme-color synesthesia experience.

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