Songbird data yields new theory for learning sensorimotor skills
By Carol Clark | eScienceCommons | Oct. 9, 2018
"Our findings suggest that an animal knows that even the perfect neural command is not going to result in the right outcome every time," says Emory biophysicist Ilya Nemenman. Image courtesy Samuel Sober.
Songbirds learn to sing in a way similar to how humans learn to speak — by listening to their fathers and trying to duplicate the sounds. The bird’s brain sends commands to the vocal muscles to sing what it hears, and then the brain keeps trying to adjust the command until the sound echoes the one made by the parent.
During such trial-and-error processes of sensorimotor learning, a bird remembers not just the best possible command, but a whole suite of possibilities, suggests a study by scientists at Emory University.
The Proceedings of the National Academy of the Sciences (PNAS) published the study results, which include a new mathematical model for the distribution of sensory errors in learning.
“Our findings suggest that an animal knows that even the perfect neural command is not going to result in the right outcome every time,” says Ilya Nemenman, an Emory professor of biophysics and senior author of the paper. “Animals, including humans, want to explore and keep track of a range of possibilities when learning something in order to compensate for variabilities.”
Nemenman uses the example of learning to swing a tennis racket. “You’re only rarely going to hit the ball in the racket’s exact sweet spot,” he says. “And every day when you pick up the racket to play your swing is going to be a little bit different, because your body is different, the racket and the ball are different, and the environmental conditions are different. So your body needs to remember a whole range of commands, in order to adapt to these different situations and get the ball to go where you want.”