How do you study the way zebrafish translate visual cues into movement, or whether mice are afraid of heights? For researchers at the Vienna Biocenter in Austria, the answer seemed obvious: build a virtual-reality rig for lab animals. So that’s exactly what they’ve done.

The new setup, called FreemoVR, is an arena whose walls and floors are made of computer displays, with 10 high-speed cameras hanging above that are able to monitor the movement of animals placed in the space. The researchers have software observe the animals' movements and quickly change the imagery shown on the displays.

So far, it seems to be pretty compelling for the critters that it's been tested on. Fruit flies that were shown virtual pillars flew in circles around them as though they were really there. Meanwhile, mice chose to walk only along raised pathways that appeared to be closer to the floor (an illusion achieved by using two sizes of checkerboard on the ground to provide a trick of perspective), just as they would in the physical world.

Details of the system, as well as results from the experiments, are published in Nature Methods. The team reckons that the setup could be used as an easier way to understand how animals respond to visual stimulation. Indeed, IEEE Spectrum reports that the lab is already investigating how differences in the brain function of fruit flies affect their responses to what they see in VR.