The neurons—found in the hippocampus—only mirror the "reality" state some 50 percent of the time.

This was according to a paper published in a recent issue of Nature Neuroscience by the team of neurobiologist Mayank Mehta, University of California San Francisco (UCSF), professor of physics and neurology, where rats were exposed to VR while their heads were partially immobilized.

"I think this paper makes it clear that spatial perception depends on a synthesis of information from multiple sources, including all the senses," Loren Frank told Bioscience Technology. Frank, a UCSF neuroscientist, was not involved in the study. "In a way, that is what makes the hippocampus remarkable: it is able to create a coherent representation of space from many different sorts of information."

Several neuroscientists contacted by Bioscience Technology agreed the work solidifies the notion that the less mobile the head during games and experiments, the more the brain experiences these as less than life-like.