Researchers from various U.S. universities have discovered how the brain adapts in order to fully use a robotic limb.
Many recent studies have analyzed humans controlling robotic arms with their brains. However, none of those studies looked at the exact way a brain needs to change in order to use such a limb.
The team in the recent study shed light on that by hooking up rhesus monkeys that had lost a limb early in life to a robot arm-controlling brain-machine interface. This allowed them to monitor changes in the brain as the animals gradually learned to function with their new arms. Not only did they find the brain does indeed change, but they also showed the monkeys be taught to control the devices over time.
“We have successfully demonstrated that learning to use a cortically-controlled brain-machine interface to perform a complex, sequential task is possible in chronically amputated animals,” the authors wrote in the study, according to Gizmodo.
To reach their conclusion, researchers implanted a series of electrodes into the monkeys’ motor cortex, on either the same or opposite side of the amputated limb. They then randomly assigned a set of brain cells to control reaching and grasping in the arm, and trained the monkeys to use the arms in ten to twenty sessions.
While the monkey with the implant on the opposite side of the brain from the amputated limb figured out the arm faster, all of the primates were eventually able to use it. In addition, the physical makeup of the brain changed as the amputee monkeys learned to control the limb.
At the start of the study, the animals only had a few connections between their neurons. However, as they learned, that cell network became more and more dense. That showed significant improvement, and the team believes the monkeys would have done better with more training.
This finding is important because it gives more evidence to the idea that the brain reorganizes its neurons to adapt to different tasks. Knowledge of that process could aid future research and help amputees control robotic arms with new brain devices.
“What’s more exciting is that brain-machine interfaces can be used to actually change the brain,” said senior author Nicholas Hatsopoulos, according to TechCrunch. “How it reorganizes with training or exposure. Just like it reorganizes when you learn to play tennis or the piano. It’s a motor skill you’re learning.”
The research is published in Nature Communications.