When a group of UCLA neurophysicists set out to discover what happens in the brain when it is exposed to virtual reality, they were in for a surprise: the brain reacts completely different in a virtual reality environment than in the real world.
These scientists studied the hippocampus of the brain. This is the part of the brain that is affected by diseases such as Alzheimer's, stroke, depression, schizophrenia and epilepsy. The hippocampus is also important for memory formation and helps the brain create mental maps of rooms so that we can navigate them appropriately.
It was these mental maps that scientists used in their research. Although we have no idea what causes the brain to create such maps, we know that they're not just based on things like landmarks. In the real world, the brain also uses smells and sounds for navigating around spaces.
So what happens when you create an environment without those smells and sounds, such as a virtual reality setting? That's what researchers did with rats by creating a virtual reality environment using large display screens and treadmills and studying the hippocampal neurons of their brains.
They also studied rats walking around in a real room similar to that of the virtual reality room.
The results of their tests were surprising: the rats' hippocampal neurons reacted completely different in the virtual reality environment than in the real world setting. In the VR world, hippocampal neurons fired randomly, suggesting that the rats had no idea where they were, even though the animals navigated the virtual setting similar to how they navigated the real world setting.
"The 'map' disappeared completely," says UCLA professor Mayank Mehta. "Nobody expected this. The neuron activity was a random function of the rat's position in the virtual world."
Researchers also discovered that when in the real world, hippocampal neurons were very active. However, in the virtual reality world, only about half of those neurons were active.
They also studied other cells in the brain, comparing what happens in virtual reality, as compared to the real world, in relation to memory. With memory, the brain has groups of neurons that communicate in two different languages simultaneously: rhythm and intensity.
In the virtual world, the rhythm "language" is similar to that in the real world, but VR disrupts the intensity language.
The idea is that because rhythms are so important in memory making, those with diseases affecting memory could have disruptions in the brain's rhythm language. Researchers suggest that using virtual reality could help trigger memory-making in those afflicted with diseases that affect memory.
"Neurons involved in memory interact with other parts of the hippocampus like an orchestra," says Mehta. "It's not enough for every violinist and every trumpet player to play their music flawlessly. They also have to be perfectly synchronized."
Of course, the brain is a complex machine and we truly do not understand every facet of how it works. But perhaps, one day, because of research like this, we'll have a better understanding of how to fix problems that affect it.
[Photo Credit: Nicole Stenger, Wiki Commons]
