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Sensory deprivation tanks have grown in popularity recently, and while the research is not extensive, scientists have found some positive effects from spending some time without so much stimulation.

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[INTRO ♪].

If there's anything we're good at these days, it's being overstimulated. Like, right now—there's a decent chance you're watching this video while scrolling through Twitter on your phone and chatting in two separate group texts and petting your pupper.

What a good boy! Most of the time, you might not even realize you've got so much info coming at you. It might actually be weirder when you don't have all that stimulation.

Enter: sensory deprivation. Sensory deprivation tanks have become pretty trendy in the past few years. Practically every lifestyle and geek-chic website worth their salt has sent writers to scope these things out. And if the anecdotal evidence is to be believed, being deprived of all sensory input is weird.

And a little freaky. But some people liked it. There's not much solid scientific evidence to back up the idea that short-term sensory deprivation has health benefits.

But there might be reason to believe that cutting off all that information can boost our creativity. And if nothing else, scientists are at least starting to understand what happens to our brains when we remove the constant, buzzing confusion of everyday life. The sensory deprivation tank experience is something like this: you climb into a pod full of skin-temperature, super salty water.

It's like floating on nothing. Then they give you earplugs and close the lid, so that it's totally dark and silent. That's when the hallucinations begin.

Yes, really. Again, supposedly, it's all quite nice. People pay serious money to spend an hour in one of these things.

Studies have shown that people's stress hormones decreased when they were in the tank. And a 2005 meta-analysis suggested that sensory deprivation reduced stress more than techniques like biofeedback (where you use ongoing information about someone's heart rate and stress levels to train them to chill) or even just plain old relaxing on the couch. But what happens to your brain while you're in there seems to be something of a wild ride.

It's worth noting that the research we're talking about here looks at short-term, voluntary sensory deprivation. There are definitely cases where it's not so voluntary and not so temporary, and long periods of sensory deprivation are a whole different beast. The experiences of people who are blind or deaf are also different than what this research focuses on.

They've shown us that the brain can be super plastic in the face of long-term sensory deprivation—basically, the baseline shifts. But, for now, back to those hallucinations. Studies have found that as little as 15 minutes of sensory deprivation can cause people to experience hallucinations.

In fact, you don't even need total sensory deprivation. Even just being blindfolded can be enough to induce visual hallucinations. There are some caveats, which may help explain why you don't always experience hallucinations while wearing noise-canceling headphones or a sleeping mask in your day-to-day life.

One of them is that some people have been shown to be more hallucination-prone than others, and those people are much more likely to experience weird sights and sounds while in sensory deprivation. The other is that expectations are probably important. In older studies that primed participants to expect something intense and scary by offering them a quote-unquote “panic button” just in case they wanted to escape, people were more likely to report vivid hallucinations.

But hallucinations do often go hand-in-hand with sensory deprivation, which fits what we see in people's brain patterns. For instance, it's been shown that theta wave activity in the brain increases and alpha wave activity decreases during sensory deprivation. Alpha waves are a type we experience when we're awake.

Theta waves, on the other hand, are associated with the first stage of sleep and with the drowsy brainstorming we often do right before we drift off. They're also associated with dreaming and with hypnagogic hallucinations, which are the trippy, vivid hallucinations we experience right as sleep takes over. This link to sleep is one of the reasons that it's not so strange to think that sensory deprivation might make us more creative.

And there are some studies to support the idea. Sensory deprivation has been shown to make undergraduates score better on creativity scales, professors do more creative science, athletes perform better, and jazz musicians improv better— at least according to listeners' ratings. The big issue is that a lot of research into sensory deprivation is kind of inconclusive.

It's cool and trendy now, but it was first studied in the 1950s, when the standards for how people were treated in studies were … different. Those early experiments actually tended use white noise instead of silence, bright light instead of darkness, and asked people to stay for as long as they could handle it. So it got kind of a bad rap, and it also got linked to not-so-great stuff like torture and brainwashing.

Which made it a bit trickier to recruit study participants. The field has mostly rehabilitated its image now, but there's still a lot of research to be done. And some of the studies that have been done in the past are too underpowered to tell us as much as we'd like.

That study about professors doing more creative science is based on five subjects. Five! And there weren't that many jazz musicians, either.

So don't get too excited. There may not be tons of answers, and a quick trip to your local sensory deprivation tank probably won't be enough to help you perfect that bluesy sax solo. But there's no denying that there are changes in your brain when you take away the stuff it usually spends all day processing.

And, you know, there's probably nothing wrong with putting on a blindfold and some noise-canceling headphones, if that's something you're inclined to do. Thanks for watching this episode of SciShow Psych! And thanks especially to our community on Patreon—we were able to create this channel because of your support, and we couldn't do it without your help.

If you're not yet a patron and you want to learn more about how you can be a part of all this, just check out [OUTRO ♪].