Can You Give Yourself Synesthesia?

Jason Padgett was, at best, an average math student in school. Then, he got mugged outside a karaoke joint in Tacoma and suffered a violent blow to the head. Within a couple days — before he’d recovered fully from his injuries — Padgett began to see the world as complex geometrical equations. He became, quite suddenly, a mathematical genius.

So did the blow unlock a dormant skill that always existed within Padgett? Or did the blow endow Padgett with an extraordinary set of capabilities he didn’t have before?

Synesthesia — the ability to perceive one sense as another, like tasting sounds or seeing numbers as certain colors (i.e., ‘3’s are always yellow) — is fairly rare. Research indicates synesthesia tends to be congenital, something you’re born with. There are some common strains, such as grapheme, where synesthetes associate numbers and letters with colors; musicians like Kanye West have reported “seeing” sounds as colors. Then there are the less understood types, like mathematical synesthesia.

No matter the form, synesthesia has become widely romanticized, probably because of the strong associations the condition has with creativity and artistic inspiration. Synesthesia, arguably, has an almost sexy aspect to it, of being a condition that offers attributes of being both unique and smart. Add the fact that synesthesia has the trippy element of “seeing” colors and the condition takes on an almost edgy vibe, a reputation that hardly any traumatic brain injury has.

In a weird, twisted way, synesthesia is almost … desirable. But could a person go so far as to slam their head on purpose to try to achieve the effects of synesthesia?

There’s not much data on people trying to induce synesthesia in themselves, via drugs, technology, or even injury, but what we do know suggests that we can get close — but never quite achieve the real thing.

But researchers are looking into this possibility. In 2013, Dr. Devin Terhune, a lecturer in psychology at Goldsmiths, University of London, co-authored a review of all available studies on drug-induced synesthesia — everything from pilot studies with a single participant to large-scale, placebo, and double-blind trials that approximated greater control. He found the literature preliminary and the data poor, but the general picture was of a link between synesthesia-like effects and serotonin. A large number of the drugs that function as serotonin agonists — that is, drugs that increase levels of serotonin in the brain — also induced synesthesia-like experiences, or at least, experiences that closely resemble what we think of as synesthesia.

There’s been a recent resurgence of clinical interest in such drugs that’s allowed scientists in the UK to more easily pursue research like this (the U.S. is more hesitant to pursue experiments on controlled substances). Terhune found that while it’s likely no drug can reproduce the experience of someone with congenital synesthesia, LSD might be the closest substitute. When subjects were asked if they experienced color or sound in an unusual way, those on LSD reported more spontaneous synesthesia-like experiences than with any other drug (though again, without differing from the placebo).

“There are methodological issues, and no single study is conclusive, but on the whole, it doesn’t look good for a hypothesis that LSD is producing the same thing as genuine synesthesia,” Terhune said. “The evidence is that the experiences closely resemble what synesthetes have, but I would probably say it’s not the same thing. That’s kind of where my intuition is going. We don’t have enough to make a strong statement, but I sense that it’s a different phenomenon.”

In a forthcoming survey, Terhune compared synesthesia-like effects resulting from all the usual suspects in addition to LSD: mescaline, salvia, MDMA, ayahuasca, peyote, psilocybin, ketamine. Even alcohol and tobacco were investigated, along with the other most common drugs, like heroin, cocaine, and marijuana.

The results were about what you’d expect, but they did show a lot of clustering — meaning that drugs in the same class tended to show similar effects. Of the 28 drugs surveyed, each of the top three shown to induce spontaneous synesthesia-like effects went to drugs in the tryptamine class; LSD ayahuasca, and psilocybin, respectively. The next most effective class was phenethylamines, like ecstasy and mescaline (salvia is basically in its own category, but demonstrated results around that same range). Dissociative drugs, like ketamine and nitrous oxide, showed similar effects to one another. Opiates, including methadone, also clustered together.

“That’s really difficult to attribute to chance,” Terhune said.

But it’s still not quite synesthesia — we think. LSD was also shown to be the most effective for inducing synesthesia in those who already had the condition. But, of course, that’s not the same as generating those effects from scratch.

Neil Harbisson, who was born color-blind and became the world’s first legally recognized cyborg when he implanted his skull with a device that allows him to perceive colors, also accomplished something just sideways of synesthesia (it was actually named sonochromatopsia).

Yet some say it’s actually technologically induced synesthesia after all. Harbisson doesn’t “see” colors — it’s more accurate to say he hears them. His implant registers light frequencies as sound frequencies. It remains unique, so we’re limited in our ability to compare his experience with that of congenital sound-color synesthetes.

In his 2012 essay, “Hearing Color,” Harbisson wrote about the experience of perceiving colors for the first time at 21.

“At first, I had to memorize the sound of each colour, but after some time this information became subliminal, I didn’t have to think about the notes, colour became a perception. And after some months, colour became a feeling. I started to have favourite colours and I started to dream in colour. When I started to hear colours in my dreams is when I noticed that my brain and the software had united and given me a new sense.”