‘The pattern of activity in a brain region involved in spatial learning in the virtual world is completely different than in the real world,’ said the professor of physics, neurology, and neurobiology.
UCLA neurophysicists have found that space-mapping neurons in the brain react differently to virtual reality than they do to real-world environments…”The pattern of activity in a brain region involved in spatial learning in the virtual world is completely different than when it processes activity in the real world..Since so many people are using virtual reality, it is important to understand why there are such big differences.”
….The scientists were surprised to find that the results from the virtual and real environments were entirely different:
- In the virtual world, the rats’ hippocampal neurons seemed to fire completely randomly, as if the neurons had no idea where the rat was — even though the rats seemed to behave perfectly normally in the real and virtual worlds.
- “The ‘map’ disappeared completely. Nobody expected this. The neuron activity was a random function of the rat’s position in the virtual world.”
“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.”
They also were shocked to find that although the rats’ hippocampal neurons were highly active in the real-world environment, more than half of those neurons shut down in the virtual space.
His conclusion: “The neural pattern in virtual reality is substantially different from the activity pattern in the real world. We need to fully understand how virtual reality affects the brain.”
Neurons Bach would appreciate
Previous research, including studies by his group, have revealed that groups of neurons create a complex pattern using brain rhythms.
“These complex rhythms are crucial for learning and memory, but we can’t hear or feel these rhythms in our brain. They are hidden under the hood from us. The complex pattern they make defies human imagination. The neurons in this memory-making region talk to each other using two entirely different languages at the same time. One of those languages is based on rhythm; the other is based on intensity.”
Every neuron in the hippocampus speaks the two languages simultaneously, Mehta said, comparing the phenomenon to the multiple concurrent melodies of a Bach fugue.
Mehta’s group reports that in the virtual world, the language based on rhythm has a similar structure to that in the real world, even though it says something entirely different in the two worlds. The language based on intensity, however, is entirely disrupted.
When people walk or try to remember something, the activity in the hippocampus becomes very rhythmic and these complex, rhythmic patterns appear, Mehta said. Those rhythms facilitate the formation of memories and our ability to recall them. Mehta hypothesizes that in some people with learning and memory disorders, these rhythms are impaired.
“Neurons involved in memory interact with other parts of the hippocampus like an orchestra,” Mehta said. “It’s not enough for every violinist and every trumpet player to play their music flawlessly. They also have to be perfectly synchronized.”
Previous research by Mehta showed that the hippocampal circuit rapidly evolves with learning and that brain rhythms are crucial for this process. Mehta conducts his research with rats because analyzing complex brain circuits and neural activity with high precision currently is not possible in humans.