There are dog heads everywhere — materializing from the sides of buildings, etched eerily into the overcast sky. A passerby turns to look at you and her body transforms into a hybrid pheasant-poodle. The sidewalk below you is peppered with eyeballs.

No, you’re not on drugs, but your brain might have a hard time telling the difference. This is an experience within the Hallucination Machine, a VR headset that immerses users in a 360-degree psychedelic version of reality that is generated with the help of Google’s Deep Dream generator.

Researchers at the Sackler Center for Consciousness Science at the University of Sussex in the UK developed the Hallucination Machine to see what altered states of consciousness can teach us about normal consciousness. Early results published in the online journal Scientific Reports point to striking similarities between the experience of virtual hallucinations and the real thing.

It’s been nearly 400 years since René Descartes first wrestled with the enigma of human consciousness, and the best minds in neuroscience and cognitive psychology are still trying to unravel the mystery of how our brains conjure up “the self” and process a constant flow of incoming sensory perceptions as “reality.”

One way to understand how a complex system works is to break it. If you want to know how the different parts of an engine work together, take out the carburetor and see what happens. The same is true of consciousness.

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To make sense of the complex relationship between external reality and internal perception, you can start by messing it up. By giving test subjects small doses of psychedelic drugs like LSD or psilocybin, researchers can study how changes in brain chemistry can disrupt the normal processing pathways of consciousness.

But giving people acid in the lab is tricky. Not only because they keep wanting to hear that same Pink Floyd song over and over, but because it’s hard for scientists to distinguish between the drug’s physical effects (sensory overload, basically) and deeper psychological shifts in consciousness.

That’s where the Hallucination Machine comes in.

“We don’t really know how drugs affect your brain,” Keisuke Suzuki, a postdoctoral fellow at the Sackler Center and lead author of the first proof-of-concept study of the VR headset’s effectiveness on human subjects, told Seeker.

“It might be that you just experience modified sensory input, not necessarily a change in consciousness,” he said. “Our machine can separate these different aspects that are normally triggered all at once when taking psychedelic drugs.”