“AI-Powered Rat Could Be a Valuable New Tool for Neuroscience: Researchers from DeepMind and Harvard Are Using a Virtual Rat to See What Neural Networks Can Teach Us about Biology”, 2020-04-27 (; similar):
Can we study AI the same way we study lab rats? Researchers at DeepMind and Harvard University seem to think so. They built an AI-powered virtual rat that can carry out multiple complex tasks. Then, they used neuroscience techniques to understand how its artificial “brain” controls its movements…Now the authors of a new paper due to be presented this week at ICLR have created a biologically accurate 3D model of a rat that can be controlled by a neural network in a simulated environment. They also showed that they could use neuroscience techniques for analyzing biological brain activity to understand how the neural net controlled the rat’s movements.
…The virtual rodent features muscles and joints based on measurements from real-life rats, as well as vision and a sense of proprioception, which refers to the feedback system that tells animals where their body parts are and how they’re moving. The researchers then trained a neural network to guide the rat through four tasks—jumping over a series of gaps, foraging in a maze, trying to escape a hilly environment, and performing precisely timed pairs of taps on a ball.
…Because the researchers had built the AI that powered the rat, much of what they found was expected. But one interesting insight they gained was that the neural activity seemed to occur over longer time scales than would be expected if it were directly controlling muscle forces and limb movements, says Diego Aldarondo, a coauthor and graduate student at Harvard. “This implies that the network represents behaviors at an abstract scale of running, jumping, spinning, and other intuitive behavioral categories”, he says, a cognitive model that has previously been proposed to exist in animals.
The neural network appeared to reuse some such representations across tasks, and the neural activity encoding them often took the form of sequences, a phenomenon that has been observed in both rodents and songbirds.