When the music changes, the streaks I can see become ripples. I’m starting to see little white dots swirling behind the colored waves like a universe of stars. Then the music changes and the colors follow. The scene now looks like a desert landscape – beige and brown stretching into the distance – except with dark high rise buildings on the horizon which I’m flying towards. I have no idea if the flashing frequency has changed, but the shapes I can see are constantly in flux.
“No one knows exactly how the Dreamachine works, we just know that it does,” says Seth. He speculates that this could be because the brain doesn’t expect any visual input – eyes are closed – and still gets some information because the light is so bright. “It’s trying to make sense of that visual input, but it can’t make much sense out of it.”
“One of the most interesting focus groups was with visually impaired people – not totally retinal blind but people with severe vision problems – it was a really deeply moving experience,” he says. “They seem to be reporting similar things to what we see in the general public. And that’s pretty fascinating to me.”
Like in a dream, I feel like time is ticking by, but I have no idea how long the machine has been running or how much longer it’s left. At some point I realize I’m barely paying attention to what I’m seeing and wonder if I fell asleep for a moment. But I snap back to the moment.
The desert has now been replaced with multicolored geometric shapes, like a simple kaleidoscope or an abstract, tessellated stained glass window. There are bright lime greens, yellows, blues and reds. The shapes move towards me as if the window were about to break. I remember the guide at the beginning explaining that all the colors I can see are created by my brain. It’s the most immersive part of the experience yet, and when the scene changes to something else, I miss the colorfulness of the stained glass.
It’s not yet clear why the brain creates colors, shapes and patterns in the Dreamachine – but Seth and his colleagues are trying to find out. He says that the patterns people see are very related to wiring aspects of the primary visual cortex. “It’s almost as if the flash activates these visual regions.”
Color vision is a fascinatingly subjective experience. The 2015 viral #thedress photo that divided the internet is a case in point, says Seth. So the age-old question of whether you and I see the same colors has a simple answer—we don’t. In fact, our own perception of color is constantly changing.
In summer, the color yellow shifts slightly towards green and in winter, for example, towards red. This could be because in summer we see more green light reflected from vegetation. We compensate for the extra green we see, which means a greenish yellow looks more like pure yellow in summer, explains Lauren Welbourne, a psychologist at the University of York in the UK.
“This idea of having different experiences of the shared environment isn’t just unique to the Dreamachine, it’s happening everywhere, all the time,” says Seth, who is also the author of Being You: A New Science of Consciousness. “We all have a unique perceptual experience, a unique inner universe. Very little is known about this type of inner diversity.”
Exploring this inner diversity is part of Seth’s next project. He and a team of scientists and philosophers collect a snapshot of the public’s uniqueness in a perception count designed to highlight the diversity of the public’s subjective experiences with a few simple questions.
Back in the Dreamachine, the music and lights fade and the guides tell us the experience is over. I compared my experience to that of another participant, and while there were similarities – a sense of 3D space, swirling stars and galaxies, and geometric shapes – it’s also clear that our journeys through our minds were quite different. It is this inner uniqueness that Seth and his colleagues hope to capture in their census.
A complex picture
While the simple colors and patterns I saw were interesting, they pale in comparison to the vivid testimonies of people having drug-induced or medical hallucinations. Why could these visions be so much more complex?
Ayahuasca and aga toad toxin contain the neurotransmitter DMT, which is closely related to serotonin, melanin, and psilocybin — the latter being the chemical that gives magic mushrooms its hallucinogenic properties. Serotonin and melanin play a role in controlling sleep, while serotonin is also responsible for our feelings of hunger, our mood, and our sense of reward.