In the smash hit Netflix series Stranger Things, the audience is introduced to a number of elements that straddle the line between science and science fiction. There is talk of multiple dimensions, a reference to the CIA’s MK Ultra and, in episode seven, we’re introduced to “The Bathtub.”

This makeshift sensory deprivation chamber gives El the environment she needs to mentally teleport to the Upside Down.

While that may not be the exact experience you have, sensory deprivation chambers very real. Let’s take a look at the chemistry behind them.

What Is a Sensory Deprivation Chamber?

Also known as an isolation tank, the idea came from a neuropsychiatrist named John C. Lilly in 1954. Lilly worked with his invention for 10 years, eventually using LSD to complement the experience (this is not the conventional approach).

These chambers come in all shapes and sizes, but the goal is the same: by depriving the brain of all outside stimuli, it’s forced into any number of activities.

The deprivation is caused by placing the individual in saltwater so that they float. This water is warmed to body temperature, ensuring the participant doesn’t feel cold or hot. They are in a chamber that is perfectly dark and lets in no noise. There is nothing to smell and nothing to taste. There is literally nothing to sense.

What Does the Brain Do When You’re Inside a Sensory Deprivation Chamber?

After your first experience inside one of these tanks, you’ll understand just how much our brain is constantly drawing on the outside world.

Unfortunately, this constant stimulation is a real drain on your brain’s chemistry. As long as you’re awake, a chemical firestorm is going on in your skull so that you’re able to make snap judgments, hold thoughts, maneuver the world around you and more.

That’s why one benefit of using a sensory deprivation chamber is that your central nervous system’s workload may drop by up to 90%. Doing so can result in an extreme form of relaxation, the exact opposite effect most people anticipate.

This phenomenon is known as the parasympathetic response and it’s used by the body to maintain chemical balance. After all, it’s not just your brain that is constantly pumping chemicals to and fro.

Other Benefits Associated with Sensory Deprivation Chambers

A recalibrating of your body’s chemistry isn’t the only benefit of these chambers, either. Many people have experienced faster healing of wounds and injuries most likely because the lesser demands on the central nervous system and the increase in T-cell production by the immune system.

The vasodilatory effect is also triggered. This is when blood pressure and heart rate drop, yet your circulation actually increases.

Floating on saltwater like this may also be good for your joints and muscles as they’re completely able to release. People suffering from rheumatic and musculoskeletal conditions may benefit greatly from sensory deprivation chambers.

So Sensory Deprivation Chambers Won’t Take Me to the Upside Down?

No, fortunately, getting into one of these chambers will not result in such a risk.

That being said, you may find that you hallucinate a bit (or a lot) while in there. This is because your brain, with nothing to focus on, begins releasing chemicals to change that. This is why I mentioned how interesting it is to see what happens when the outside world isn’t there anymore.

For some people, the chemicals associated with dreaming will ramp up considerably. Many people have seen lights or even sworn they spoke to aliens. Don’t worry, though; no one has ever suffered a mental breakdown or any other kind of long-term injury from using these tanks.

In Stranger Things, the idea seems to be that El can mentally travel to the Upside Down when her brain is allowed to let go of her current surroundings. Don’t expect the same thing to happen when you enter one of these chambers, but you will most likely experience something a bit out of this world.