A machine-learning engineer figured out a way to allow rats to play Doom II. The rats play the video game by rotating a polystyrene ball with their feet. For the experiment, the engineer suspended the rats over the ball via a little harness. In front of the rats’ faces he placed a curved screen on which Doom II appeared. To navigate the game, three rats were trained using sugar water as a reward. As well as puffs of air to the face and/or rear as negative inputs.
Placing the rat on the giant scrolling ball in front of the screen, the engineer then presented the rats with various levels from the video game; when the rats ran into walls, they received puffs of air. When they continued through the maze-like levels, they received sugar water. In terms of the results, the three rats could all run through the levels to some extent and each of them had different strengths and weaknesses.
More information:
https://nerdist.com/article/rats-play-doom-ii-using-mini-vr-rig/