An interdisciplinary team of biologists and software engineers have developed a virtual reality arena for small animals that simulates real world environments.
The new setup is designed for experiments that precisely measure animal behaviour and visual decision making. The method combines the control afforded by laboratory settings with the ecological relevance of natural settings, albeit simulated.
While the insect subjects were not given tiny headsets, the 3-screen setup displays a 3D virtual environment that updates in response to their movements.
Insects inside the arena were glued to a stick and taught to fly while tethered. Senior author Karin Nordström of Flinders University in South Australia told Cosmos this step was “surprisingly hard”.
“We recorded their wing movements in infrared, which they cannot see, and in real-time calculated their wing beat amplitude (WBA),” says Nordström. “If the WBA increased, we interpreted this as them trying to fly faster. If the WBA of one wing was higher than the other, we interpreted this as a turn in the opposite direction.”
Nordström and colleagues fed this information into a virtual world generated in Unity, a 3D game development platform, which then updated the visual displays. Closing this loop fast enough to give the animal the impression of moving was another technical hurdle.
According to coauthor and computer scientist Raymond Aoukar, “The last two decades have seen very rapid advances in algorithms and computer technology, such as virtual reality, gaming, artificial intelligence, and high-speed calculation using specialised computer hardware in graphics cards.”
“These technologies are now mature and accessible enough to run on consumer computer equipment,” adds Aoukar.
Nordström’s team intends to share access to both software and hardware with interested researchers. To demonstrate their method’s applicability to other organisms, the team also tested it with crabs walking on a trackball.
“I am a strong believer of open source – science is after all mostly paid by taxpayers – and I want to share our excitement as much as possible,” says Nordström.
The research is published in the journal, Methods of Ecology and Evolution and the open source software is available on GitHub.
