So many things have made this summer feel as though we’re living in an alternate reality, walking around in a daze under record-high temperatures, preparing for nuclear warfare, and secretly hoping the total solar eclipse was just a cover for aliens coming to claim Earth and solve all of our problems. But really, it doesn’t take much to push the human mind off the cliff of reality, to go from a casual stroll down the block to believing you’re wandering around lost in the sewer pipes of Derry, Maine with the rest of the Losers’ Club. That’s exactly where I found myself this past weekend, courtesy of the IT Virtual Reality Float experience, which fittingly made its first stop right outside the city of brotherly love. We’re coming to save you, Georgie!

The experience began by entering the bus with seven other Losers and waiting inside a makeshift sewer, complete with wafting fog, dripping water, and startling sound effects. After a few minutes, a set of double doors opened and an assistant invited us to take a seat in swiveling office chairs and put on the VR headset and headphones. From there, we were all transported to the streets of Derry and into the underground labyrinth of pipes where Pennywise teased and tormented us with delightful scares, including bursting blood-filled balloons and an incredibly convincing, stomach-dropping descent down a sewer drain. It was a terrifyingly fun time, made possible by our surprisingly easy-to-trick systems of perceptual awareness.

We take for granted that what we see and experience is an accurate representation of what is really happening. Think about it: if we had to consciously process every bit of sensory information, we’d never make it out the door. This means our perception can be off, and even better, that we can manipulate perception in fun and interesting ways. (Anyone remember the 1994 Brainscan with the adorable Edward Furlong?)

The IT experience was a passive 360-view virtual reality, meaning I couldn’t act on the environment, but the 360, 3D digital environment did have me convinced I was actually in the space. The big challenge with these experiences is figuring out how to convincingly move the user through the space and make them forget they’re actually seated in a comfortable swivel chair. This requires successfully manipulating our sense of body ownership, which is tough and very expensive.

Full immersion, or having a sense of presence in a VR space means creating a convincing place and plausibility illusion. Place illusion is more than excellent graphics and detailed scenes, it’s about matching our movement with our view of the surroundings—the turn of our head, the reach of our arm, and the expensive part: the movement of our legs and body. The second part, plausibility, means the environment changes with our interaction with it: ghosts turn to look at us, zombies die with the swing of our axe, etc. Taking it a step further, if you have additional systems to generate associated noises, smells, and even tactile sensations (the sting of a needle, the vibration of a land mine), then hello full immersion!

We don’t consciously think about it most of the time, but the way in which we know that our body belongs to us, that the hands on your keyboard and the leg tapping against the floor belong to you, is not as simple as it feels. Our sense of body ownership depends on bringing together the signals—inputs, if you will—or messages that are coming at us from every direction: from our eyes, our nose, our skin, our taste buds, our ears—each of which contain their own precise systems of coding and signaling. All of this has to come together to create a cohesive picture of reality so we can act. And, because we want to act, and react, as quickly as possible, our brain often fills in the blanks based on previous experience and predictions, only correcting the picture if conflicting information is registered. It’s all about maximizing efficiency. If you can create a convincing enough substitution of reality, our brain is likely to accept it without challenge. The best way to illustrate this is with the rubber hand illusion, a go-to of street performers across the globe.

*Image credit: Tami Tolpa via The Scientist Magazine.

Typically, an innocent passerby is invited to have a seat to experience a hand transplant, and then told to watch a rubber hand, which is placed right above theirs on top of a table. Then, the magician “prepares” the transplant by brushing both the fake and real hand at the same time. After less than a minute of this simultaneous brushing, our brain adopts the rubber hand as our own. This makes sense when it comes to processing quickly: our eyes are telling us we should feel something, our skin is reporting that we do, there’s no reason (or error message) telling us we should doubt this (as long as your real hand is kept passive and relaxed). So, when the magician, as the gag goes, swiftly switches out the gentle brush for a hammer, or if they’re really evil, a knife, and brings it down and stabs directly through the rubber hand, we instinctively pull back with a startle or scream. Even more creepy, researchers found that blood flow and temperature of your “neglected” hand under the table go down, suggesting we’ve really “forgotten” our real hand. This can work in the opposite direction as well. When researchers applied pain-relieving cream to the rubber hand, subjects reported their pain decreased!

There are other ways, though less entertaining, to make us feel like we’ve lost touch with reality and our own body. One of them involves lots of projectors, and a precisely timed delay. Imagine this: you’re standing in the middle of a mirror maze, reaching out until your fingertips connect with their mirror image—only the finger you were expecting to meet your own arrives one second later. This is what one group of researchers studying embodiment and time perception did, and not only did this seriously distort subjects’ sense of time and body ownership, but they felt like they were sinking into the pictures.

Other non-drug-related methods shown to induce out-of-body experiences include synchronising your heart beat with a flashing light that is set to illuminate an outline of your body with every beat. Soon, you’ll start feeling a connection to the body you’re seeing, rather than your own. And of course there’s the go-to sensory overload or confusion: strobing lights, audio and physical sensation manipulation. Or, the total opposite: sensory deprivation via sound-proofing, confinement, or float tanks (think Stranger Things). Your mind is looking for information to process and finding none, starts making things up, e.g. audio and visual hallucinations. Bottom line: if you start messing with our input signals, our grasp of reality can slip away within a heartbeat. So, maybe we are living in an alternate reality, even Elon Musk thinks we are. The question, then, is do you want to wake up?