Virtual reality was learned by insects and mice

Virtual reality was learned by insects and mice

In the journal Nature appeared an interesting publication on the topic of virtual reality

Scientists have created a special installation, on which the mouse is fixed behind the head, while the rodent has the opportunity to run along a kind of treadmill - a ball that turns in any direction. The movement of the ball is recognized by the computer and allows the system to understand which way the mouse is running in order to generate the corresponding image. The scene is presented on the screen in the form of a torus, covering almost the entire field of view of the mouse.

The essence of the experiment is that the mouse solves the navigational task by moving around the virtual labyrinth (created, by the way, on the Quake2 engine), in one of the corners of which the "reward" is hidden: when the mouse reaches the desired point, the tube is supplied with sweet water. At the same time, scientists are monitoring the so-called placecells in the hippocampus due to the fact that the mouse's head is actually immobile. The fixed head allows you to observe the activity of living neurons through a special window using a two-photon laser microscope. And in order to observe the cells of the hippocampus, it was necessary to remove a small layer of the bark lying above it (no one will allow such manipulation with the person, it is possible only in rare medical cases).

Thus, scientists study how the cells of our brain allow us to navigate in space to all mammals, and hence not only to rodents, but to us, people.

As a result of the work, it is established: the neurons responsible for navigation, the so-called gridcells (coordinate neurons), bordercells, headdirectioncells (head direction neurons) showed activity corresponding to navigation in the real world. That is, the use of virtual reality to study how the brain navigates, is quite valid.

Virtual reality systems for rodents have evolved, receiving various modifications: in 2014, a similar virtual reality (VR) for rats with only a conical screen was created so that the rat can still turn on the sphere, the equipment is fixed to the head with a special flexible arm. In this system, the head of the rodent is not fixed, and the field of view is 360 °. [Aronovetal, 2014]

It seems that the virtual reality for a rodent is something exotic, but do not rush into evaluative judgments, everything is relative, here's a virtual reality for a butterfly. This is a system for simulating flight of an insect, which includes visual, olfactory, mechanical impact, as well as multichannel recording of neurophysiological parameters. [Gray, 2002]

As a model organism, the tobacco brazier (Manducasexta) is used. The butterfly is fastened with the front part (breast) to the podstavochke on the glue - the experimental insects are often disposable, such are the everyday life of science. In front of her is a screen with visual information (again on the game engine), a source of air flow into which pheromone can be fed - attracting the male's smell of a female. Movement of the abdomen to the right and left is removed by an optical sensor, this allows the system to track where the insect wants to turn in flight, and record a virtual trajectory in the playing space for later analysis. The virtual world is represented by a flat plane with randomly arranged "cushions" on it - small obstacles. Since only the right-left turns are tracked, the flight actually takes place in the same plane, with a constant speed roughly corresponding to the speed of the flight of the gambler - each virtual reality has its limitations