This Flickering Machine Can Hijack the Brain’s ‘Reality Engine’—And Reveal a Hidden World Inside the Mind

Here’s what you’ll learn when you read this story:

• The Dreamachine is a 1950s-era invention that uses patterns of flickering light to alter human perception and ultimately, its creators hoped, even consciousness.
• In 2022, more than 50,000 people experienced a modern Dreamachine installation, reclining in a darkened room as flickering light and music guided the experience.
• The visions people reported ranged from geometric patterns to memories and intense emotions, underscoring how differently our brains can interpret the same sensory input.

In the village of Chudleigh, rows of cream-colored homes line narrow English lanes. Six-hundred-year-old edifices share the high street with modern retailers and charity shops full of random old items. Jennifer Crook, 17, loved to explore these shops, and it was on one of her excursions that she encountered a little book called Flickers of the Dreamachine: The Definitive Headbook.

“I took this thing home and in the back of it was this kind of really strange fold-out piece of paper with a pattern on it. I was like, what the hell is this?” Crook recalls. “And I dug under the skin of it and realized that this was a blueprint to make this thing called the Dreamachine. … [Then] I built a portal to consciousness in my bedroom.”

Her copy of Flickers was one of about 100 published in 1996. It was considered the definitive collection of essays and history dedicated to the Dreamachine, a construction paper gadget that creates a pattern of flickering light designed to alter consciousness. You cut out the geometric shapes; glue the paper into the shape of a cylinder; set the contraption on a 78-rpm record player (Crook was lucky her mother still owned one); and hang a light on the inside. Then, you sit with eyes closed before the rotating device as flickers of light play on your eyelids and allow you to see what your mind creates.

The device was invented in 1959 by beat artist Brion Gysin and computer programmer Ian Sommerville, both friends of William S. Burroughs. The story goes that Gysin was riding a bus at sunset with his eyes closed when he passed under a row of trees whose leaves flickered shadows over his eyes. Suddenly, in his mind, he began to see shapes, images, colors, and full-blown scenes. This, he thought, would be the antidote to that new evil—the television—that was draining everyone’s awareness. With this, people could explore the magic within their own minds instead.

Put another way, the Dreamachine induces visual hallucinations. But if a few pulses of light can make the brain generate an entirely new visual world, it raises the question: Is the reality being constructed inside our own heads … real? Yes, says Reshanne Reeder, PhD, a cognitive neuroscientist at the University of Liverpool. And no.

Reeder wasn’t involved in the Dreamachine project, but she made a YouTube version as part of her “journey to find a relationship between hallucinations, mental imagery, and perception.” She said that a shared mental image—say, a brown horse on a green field—registers the same on our occipital lobes, the part at the back of the brain that processes visual stimulation. But as the image touches our memory, emotions, and beliefs, it changes: what is highlighted, what is felt, what is remembered. So we all do have our own reality, in a sense.

When your eyes are closed, or you’re looking only at a flickering screen, the lack of sensory input draws focus to your internal states, which can cause spontaneous neural activity that is likely to feel like a meaningful, complex experience.

For the teenage Crook, the Dreamachine was actually a bit of a dud. “It worked just enough that I was fascinated by it and experimented with it,” she recalls. She grew up to curate public art exhibits, and kept her Dreamachine as an oddity, but rarely thought about it—until 2014, when she attended a concert by composer Jon Hopkins, a protégé of Brian Eno, who pioneered ambient music. The concert was widely hailed as a transcendent experience. It pulled people out of their seats and turned the formal concert hall into a magical rave.

Afterward, Crook says she began to make connections between that concert and the paper contraption still sitting in her apartment. She wanted to use the Dreamachine to help people experience an altered version of reality alongside others doing the same. She became “a mad, obsessed woman,” while she worked to assemble a team that could pull it off.

Then in 2020, in the middle of the COVID-19 lockdown, the U.K. government announced £100 million (about $134 million) in new funding to be divided among 10 public projects covering science, technology, engineering, art, and math. Anyone with a compelling team and idea could apply. Crook convinced Hopkins—who had made an album for psychedelic therapy—to create the music; and Anil Seth, PhD, a neuroscience professor at the University of Sussex, to oversee the brain and consciousness aspects.

Seth became internationally famous in 2017 for his TED Talk on how your brain hallucinates conscious reality. He recalls that a lot of people did not like being told that their experience of reality wasn’t the true, accurate, correct one. He wasn’t saying that there is no objective reality, he explains; he was just saying that each of us has an interpretation of the shared objective reality we experience. He was the perfect fit for Crook’s team.

Their Dreamachine proposal was among the winners, and the resulting experience was held in the U.K.’s four capital cities: London, Edinburgh, Cardiff, and Belfast. It ran 12 hours a day, seven days a week for five months. Crook said every seat was full; more than 50,000 people attended.

In a small space designed to make participants feel held, people were invited to take off their shoes, put away their phones, do a deep breathing exercise, and then recline in the dark while Dreamachine flickered above them. Hopkins’s music created an arc—a beginning, middle, and end to the experience.

Afterward, participants were led into the reflection room where staffers offered to help them process what they had experienced. At a center table, participants could draw what they’d seen. “People had very profound emotional experiences,” Crook says. “We saw a lot of grief, a lot of buried sadness or loneliness. For the first time, people were given a space in which to sit with themselves for an hour or so with their feelings and with other people around them.”

One of those people was Daniel Tudor, a young man who attended the experience 27 times in London. The Dreamachine, he says, allowed him to process unresolved trauma, including the death of his father. After the experience, he called his mother to tell her about it, and “started to cry very hard,” he told the Dreamachine team. “I have never cried in front of my mum before. It was like the experience in the Dreamachine released those emotions which I had buried since childhood.” Since then, Tudor says, he has become calmer, happier, lighter, more accepting of life as it is, more humble and tolerant, more accepting of others’ views.

So how did the Dreamachine experience facilitate that? It comes down to the way our brains experience our environment, says Reeder.

We all sample the world in constant, rhythmic flashes, though that’s not what it feels like. Our neurons fire rhythmically and are connected to one another at different frequencies, Reeder explains. But if you introduce an external rhythm from the environment—like a flicker, or a drumbeat, or a chant—the neurons entrain on the new rhythms, changing their firing patterns and the way they interact with one another, creating an altered state of consciousness. When the stimulus is visual, it affects our neural or cortical columns, a vertical group of neurons in the brain’s cerebral cortex that span all six of its layers and that map to our retina. For most people, this results in one or more of a common set of “hallucinations”: spiderwebs, tunnels, honeycombs. These geometric visual hallucinations are closely related to the cortical mechanisms used to process edges, contours, surfaces, and textures.

But some people see a lot more than basic shapes and patterns.

This altered state of consciousness is known as the flicker effect, and experts believe its roots may date back to early humans sitting in the dark, mesmerized by the first fires.

Dreamachine participants created tens of thousands of artworks and recorded hundreds of verbal expressions after their experience. Some felt peace and spiritual connection, others anxiety; some had memories or feelings that they connected to what it must be like while you’re dying; some had out-of-body experiences. Analysis of these experiences is difficult, Seth says, since they weren’t created as part of a study. But it’s still a massive body of data that he and his team will continue to work with.

For participants, it was a visceral and personal moment shared with a room full of strangers whose diverse experiences seemed beautiful and interesting instead of scary. Now, Crook is creating a permanent Dreamachine exhibit for the UK as well as a traveling exhibit.

“The purpose was for people to see that you have your own internal experience and everything else is kind of an illusion,” Crook says. “And there’s that moment that the veil comes down and you realize everyone else is feeling what you’re feeling.”