When virtual reality helps reveal the secrets of our memory
We no longer count the potential applications of virtual reality in the medical sector : helping patients fight their phobias, escaping for a few hours during a long-term hospitalization… And this technology even proves useful to better understand how our memory works ! This is what neuroscientists from the University of California (USA) announce in the journal Nature Communications : virtual reality has allowed them to discover that two distinct areas of the hippocampus, key region of our memory, are activated according to two types of memories : episodic and spatial. But until now, it was thought that the hippocampus was mainly involved in space memories.
Remembering a unique experience, we think back to other similar memories
It is known that a single memory can trigger other associates, for example those that occurred in the same place. In order to visualize this in the brain, the scientists recruited 28 participants who, wearing helmets, virtually “visited” several houses, in a series of videos. They had to spot particular objects, and memorize both in which videos an object appeared (episodic memory) and in which houses they found it (spatial memory).
While participants were asked to remember these objects after viewing, their brains were subjected to functional magnetic resonance imaging (fMRI). This technique makes it possible to visualize the areas of memory in action, in particular the hippocampus. Balance: Two distinct areas of this brain region were activated depending on the type of information sought. One is involved in the representation of information related by a context (e.g. objects present in the same house) and another area is related to differences between information, such as the same object found in several houses. “This means that even if you try to remember a unique experience, the hippocampus will still be involved in connecting similar experiences, explains Halle Dimsdale-Zucker, co-author of the study, in a statement. You need both of these areas to be able to remember.”
For this researcher, virtual reality experiments could help to learn more about our episodic memory, and more generally, how our memories are formed, stored and resurfaced. Information that could be useful in order to better diagnose Alzheimer’s disease, according to him.