Here's the Real Reason Why Virtual Reality Doesn't Work Yet





But once this map has been created, rats can quickly figure out where they are should they return to that location.

Scientists have theorized that rats don’t require much sensory information to build these maps, figuring that distant visual images, the ability to move themselves around, and maybe some proprioceptive orientation is all that’s required to do the trick. But as the new study by Pascal Ravassard and colleagues has shown, that’s not enough — and not enough by a mile.

To reach this conclusion, Pascal Ravassard and colleagues experimented with rats placed in a virtual reality environment. Indeed, VR is becoming a popular tool amongst some scientists. For example, researchers have interacted with rats by becoming virtual rats themselves, and they've gotten monkeys to feel virtual objects by using a brain implant.

But as this experiment showed, getting a rat's brain to respond to a VR environment in the same way it responds to the real world is not so easy.

For the study, the researchers tried to create two apparently identical worlds, one real (RW) and one virtual (VR). Each environment consisted of a linear track in the center of a square room with distinct visual cues on each of the four walls. These cues were nearly identical in both environments, but the rats' bodies were fixed in VR — thus minimizing (or even eliminating) other important spatial cues, like balance. So, the only incoming environmental data during VR exposure were the visual cues and self-motion.

Here's the Real Reason Why Virtual Reality Doesn't Work Yet

After attaching tetrodes to measure the neural activity of six rats, the researchers had them run the track in both the RW and VR environments. When looking at the results, it was clear that the VR environment was not exciting the place cells as per usual. In VR, place cells showed 20% activity as compared to 45% in RW — more than twice as much.



Read the entire study at Science: “Multi-Sensory Control of Hippocampal Spatiotemporal Selectivity.”