"We think when you're walking around in the real world, you're getting input from multiple senses, and they're all in perfect agreement," said Mehta, who studies how virtual environments affect the brains of rats, at the level of individual neurons.
In virtual reality, however, "the brain is expecting everything to be in sync, but things are not in sync," he said; the virtual world is "incomplete."
Brain shutdown In Mehta's studies, he and his colleagues built special setups with tiny treadmills that the animals could run on while exploring a virtual room. The rats appeared to behave normally in the setup, but when the researchers looked at the animals' brains, they "found really surprising stuff," Mehta said.
For example, in the hippocampus, a brain region involved in mapping an individual's location in space (as well as many other functions, including memory, learning and dreaming), 60 percent of neurons simply "shut down" while the animals were in virtual reality, Mehta found.
And it gets worse. Many of the neurons that don't shut down show abnormal patterns of activity. In the real world, these neurons create a map of space, but in the virtual world, "the map of space is totally destroyed," Mehta said.
Mehta suspects that the part of the brain involved in keeping track of an animal's location is so fine-tuned that it "expects" everything to be in sync. "I believe that's why these neurons are shutting down" in virtual reality, he said.
But is it bad for the animals that the hippocampus shuts down in virtual reality? "We don't know the long-term consequences," Mehta said.
"When millions of us are using virtual reality 6 to 7 hours a day," he said, "we may want to look it, given that it's such a big change."
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Top 10 Mysteries of the Mind This is a Rat's Brain on Virtual Reality | Video 10 Things You Didn't Know About the Brain Original article on Live Science. Copyright 2015 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.