The first time I dropped acid, my friend put on some techno music, telling me the drug would give it cool effects. It did indeed. With each note, it felt as if someone were tapping on my skin. I wondered if I was actually feeling the sound vibrations. More likely, though, this was happening because psychedelics cause synesthesia, or the mixing of senses. While my synesthesia involved the melding of touch and sound, some describe “hearing” colors, “seeing” music and other combinations of sense.
“Sometimes, I'll taste a color on my tongue,” says one anonymous 25-year-old content strategist in Brooklyn. “Other times, I'll feel sensations from other colors. I had a very intense experience while using 2C-B—a synthetic mixture of acid and molly—while at Burning Man in 2017. I had been feeling warm from different warm-tone colors—yellow, orange, magenta and red—and when I went into a dome that was mostly colored red and orange, I began to overheat. My partner pulled me away from the dome to look at cooler-toned colors. We found a yellow-green car, and when I looked at it, not only did I cool down, I also could see the colors pulsating from the psychedelic effect that was creating a tone with every pulse, so in an effort to control one synesthesia episode, I experienced another."
Another common experience is seeing objects “breathing.” This may not seem like synesthesia at first glance, but if you pay close attention, you might notice that the sensation of your lungs filling with air is triggering these visuals.
“When you breathe, the sound/feeling of your own breath also engages your visual cortex, causing you to perceive things—the walls, your bed, etc.—to be breathing,” says Chris Rice, author of On Culture: Small Minds, Big Business, and the Psychedelic Solution and director of Mushroom: A Lost History.
Many psychedelic users have had experiences like these.
“Most phenomenological recounts of psychedelic experiences, particularly LSD or psilocybin, are particularly rich in synesthetic content,” says James Giordano, professor of neurology and biochemistry at Georgetown University Medical Center. “Multiple integration of sensory phenomena will create a richness or a distinct flavor they experience.”
When you get synesthesia, the boundaries between different sensory processing areas in your brain disintegrate, Giordano explains. “When we are little babies, we probably process senses in a very multifactorial way,” he says. “Our senses overlap.”
Then, as we get older and use our senses more, we learn to distinguish between different types of stimuli and suppress the connections between different sensory processing areas in our brains so we don’t confuse them.
Psychedelics un-suppress these connections by disrupting a pattern of neural wiring called the “default network,” says Rice. “On a day to day basis, healthy adults operate in what is referred to as ‘default neural mode’ or the ‘default mode network,’ which more or less equates to finely grooved pathways through which your brain typically operates.”
“What a psychedelic drug can do is disinhibit the usual pattern of network activity in the brain,” explains Giordano. “It can alter the default network and, as a result, it opens up possibilities from multiple networks of sensory processing and integration and opens up the possibility that people will experience synesthesia. Some people find that to be very creatively rich, and others find it to be a little terrifying.”
Some people experience synesthesia innately without any psychoactive substance, but as far as Rice knows, there’s no other way to artificially induce it. Psychedelics’ ability to eradicate the boundaries we impose on the world is one of their biggest appeals.