To experience an alternate state of mind, just strip down, get into some salt water and float for an hour.

It may sound crazy, but not to the Penn State researchers studying what experiences people have when they float inside a sensory deprivation tank filled with salt water, the only of its kind in North America, said study coordinator Dalton Hance.

The process is called Restricted Environmental Stimuli Therapy (REST), said Penn State English professor Richard Doyle, who is part of the team investigating the study along with lead investigator Mark Shriver, professor of anthropology.

"In our collaboration, we discussed how interesting it would be to look at research with floatation tanks," Doyle said. "I'd long been interested in trying to study human consciousness and its alternation in a way that's legal."

The idea of the tank came out of research done in the 1950s to understand how beliefs are formed in people, he said.

Doyle said there was a lot of research done with floatation tanks and alternate perspectives in the 1960s and 1970s, adding that the research might have stopped because it seemed to be associated with the "culture of the time."

The researchers are working on two different studies now, Hance said. One study involves a single one-hour float, after which the researchers gather written responses from the participants, Hance said.

He said they are trying to find a correlation between people's DNA and the experiences they have.

"Biological and cultural factors influence the external environment," Shriver said. He added that the researchers don't yet know what influences people when they're inside the tank.

"It's only our second year running the tank," Shriver said, adding that researchers are still analyzing data from the previous year.

People can choose to float in a bathing suit or nude and must take a shower before they go in the tank, he said.

Any sediment, hair or bacteria in the tank is cleaned out by a filtering process that Hance said is run at least twice a day and between each float.

Inside the tank, 11 inches of water is heated to skin temperature and then saturated with hundreds of pounds of Epsom salt, allowing a person to float with hardly any effort.

"You bob on top of [the water] like a hyper cork," Doyle said.

Earplugs are provided to keep water and sound out.

When the participant is ready, the researcher turns off the lights and the floater shuts the door to the tank, immersing them in complete darkness for an hour.

"You close the door, and there's no other input. Nothing happens. It's a very gentle meditation environment," Doyle said. "It's not anything to make people feel any anxiety."

Doyle said between 60 and 70 percent of participants feel like they're flying and many lose all sense of up and down.

"You can really lose awareness of the boundaries of your body," Shriver said. "The weightlessness is unique. I wish I had one at my house."

Doyle said that so far they have been getting good responses.

"One of the most common symptoms is wanting to float again," he said.

Of about 100 people who have floated in the tank, Hance said two ended early because they didn't like the feeling.

"That's to be expected," he said. "Some people don't want to spend that much time with themselves."

Hance said he would like to get a neuroscientist on board to see what kind of brain activity is going on as people float, though he said it would be hard to do in the water environment.

"I would hope we would expand," he said. "There's a lot left to be answered."

The other study the researchers are planning will begin next week and will require 20 participants to float 12 times for 45 minutes each in a period of seven weeks, he said.

This study focuses less on narrative experiences of floating, but more on individuals with different personality traits and how they experience the tank, Hance said.

Anyone can sign up to float.

"It's one of those things you have to experience for yourself," Doyle said.