One of the most important considerations for creators and consumers of VR is the physiological effect that immersion can have. Short-term physiological responses like increased heart rate or perspiration are signs of effective immersion. Currently, VR experiences rarely last more than 20 minutes. This is due to other short-term responses that VR can cause like dizziness, fatigue, and motion sickness. As technology improves, immersion time may increase, and this brings up an important concern – what long-term effects can virtual immersion have?

A team of neurophysicists at UCLA has been researching this topic as it relates to the region of our brain called the hippocampus. This region is thought to be the center of emotion and memory, and is directly involved in conditions like Alzheimer’s, depression, schizophrenia, PTSD, and epilepsy. The hippocampus is also responsible for our ability to spatially map out physical environments, but as concerns current VR technology, it relies on more than just visual cues to do so. The scientists at UCLA conducted an experiment measuring brain activity in rats as they participated in a VR experience. The results of this experiment showed that in VR, the hippocampal neurons fired with complete randomness. Their spatial map disappeared entirely, and whereas the rat’s hippocampal neurons were firing actively in real world environments, in virtual reality over half of these neurons shut down completely. Even more surprising is that on the surface the rats appeared to behave normally in virtual space. One major concern is that the activity pattern measured in the rats’ brains as they participated in VR resembled the activity pattern measured by rats in the physical world who suffered from Alzheimer’s disease.

The UCLA team also looked at larger groups of brain cells in this experiment. Previous research in neurophysics has shown that neurons form complicated patterns using brain rhythms. Dr. Mehta, senior author of this study on rats, says, “These complex rhythms are crucial for learning and memory… 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.” The experiment on the rats showed that in VR, the rhythm-based language looks very similar to its physical world structure, but communicates a different message. The intensity-based language, however, is completely disrupted. The research team believes that by focusing on these neuronal rhythms, informed scientists in the future could use VR to retune and synchronize them in a manner that will improve damaged or impaired memory.

These results highlight how the potential of VR extends beyond just the field of entertainment. This study deals with just one aspect of the long-term physiological effects that VR can have. It is clear that the implications of long-term usage are serious, and being informed about what we are creating and consuming will determine whether these experiences enhance or diminish the quality of our lives.