Researchers from Professor Krishna Shenoy's Group: Saurabh Vyas (Bioengineering PhD candidate), Daniel O'Shea (EE postdoctoral researcher), and Professor Stephen Ryu, M.D. have found that the brain is deeply interested in what happens before you make a movement. Their paper was published in cell.com's Neuron.
Existing theories focus on the practice part — the repetition — not the preparation.
In fact, prior to this study, neuroscientists had no reason to think this preparatory state played any part in learning, says Krishna Shenoy. "We're saying that preparation not only has something to do with learning, it might actually be one of the biggest parts of it," adds Krishna who is a Howard Hughes Medical Institute investigator.
To arrive at this new understanding, the researchers explored how monkeys learn a relatively simple motion: how to use a videogame joystick. In a series of experiments, they first trained the monkeys to use the joystick to direct a computer cursor toward a target on the screen. Next, the scientists altered how the joystick worked so that when the monkeys moved the joystick in the direction they thought was upward or leftward or rightward, the cursor moved in a different direction than expected. Thus, the animals had to learn to move the joysticks anew to get the cursor to the target.
Saurabh Vyas uses an analogy to explain the significance of these findings. Imagine LeBron practicing free throws. He shoots the ball, and gets close, and his learning system uses the error to make some changes in the brain. But if his brain activity is disrupted during the planning period — or he doesn't take an instant to pre-visualize the shot — his next attempt will not do as well because he wasn't mindful enough during the critical, pre-movement period.
These findings significantly advance our understanding of the neurological underpinnings of learning. It has long been known that motor and other areas in the brain become active prior to movement. During this preparatory phase, brain activity reflects precise details of how the body should complete a movement.
Consequently, giving the mind more time to prepare — more time to visualize the task at hand — substantially improves learning. From a purely practical standpoint, the findings could reshape how athletes, artists, musicians or anyone who moves their body gets better at what they do.
Ultimately, Krishna and Saurabh hope to apply this new understanding to their specialty: developing prosthetic devices that are controlled by chips implanted in the brain that transform an individual's thoughts into movement. Krishna adds, "The more we understand about how the brain learns new motor skills and performs movement calculations, the more lifelike and realistic we can make thought-controlled prosthetics."
Excerpted from Stanford Engineering,"A team of scientists explore how the brain trains muscles to move" February 26, 2020.