SHAFAQNA (International Shia News Association) An Iranian researcher Zahra Aghajan along with neurophysicists from University of California, Los Angeles UCLA studied the hippocampus, a region of the brain important in forming new memories and creating mental maps of space.
When you explore a space, hippocampal neurons become active and provide a “cognitive map” of the environment.
It’s been found that space-mapping neurons in the brain react completely differently to virtual reality than they do in the real world.
Scientists aren’t really clear how the hippocampus does this, but they believe that it computes the distance between the subject and surrounding landmarks. The brain also uses other cues such as smell and sound to measure distance.
To see whether the hippocampus could form spatial maps using only visual cues, Mayank Mehta, a professor of physics, neurology and neurobiology in the UCLA College and his team created a virtual reality environment and studied how the hippocampal neurons in the brains of rats reacted without the ability to use sound and smell.
Analyzing complex brain circuits and neural activity with high precision is currently not possible in humans.
They put the rats on small treadmills surrounded by a virtual world on large screens in an otherwise dark and quiet room.
They measured the rats’ behavior and the activity of the neurons in their hippocampi before doing the same when the rats walked into a real room, designed to look exactly like the virtual one.
The scientists were surprised to find that in the virtual world the rats’ hippcampal neurons fired completely randomly, as if they had no idea where the rat was. This was despite the rats’ behavior being completely normal in both the real and virtual worlds.
They also found that in the virtual space, more than half the neurons that were highly active in the real-world shut down.
“In fact, careful mathematical analysis showed that neurons in the virtual world were calculating the amount of distance the rat had walked, regardless of where he was in the virtual space.” said Zahra Aghajan, a UCLA graduate student and another of the study’s lead authors.
They concluded that more needs to be done to understand the impact of virtual reality on the brain.
The study was published in the journal Nature Neuroscience.