Providing Simple Neural Signals to Brain Implants Could Stand in For Body's Own Feedback System, Study Suggests
Monkeys can lean simple brain-stimulation patterns that represent their hand and arm position, and can then make use of this information precisely to execute reaching maneuvers, a new study has shown.
The study brings natural movement by artificial limbs closer to reality.
Goal-directed arm movements involving multiple joints, such as those we employ to extend and flex the arm and hand to pick up a coffee cup, are guided both by vision and by proprioception-the sensory feedback system that provides information on the body's overall position in three-dimensional space. Previous research has shown that movement is impaired when either of these sources of information is compromised, the press release added.
"State-of-the-art BMIs generate movements that are slow and labored-they veer around a lot, with many corrections," Philip Sabes, PhD, senior author, whose research to improve prosthetics has been funded by the REPAIR (Reorganization and Plasticity to Accelerate Injury Recovery) initiative of the Defense Advanced Projects Research Agency (DARPA). "Achieving smooth, purposeful movements will require proprioceptive feedback."
"The brain is remarkably good at looking for 'temporal coincidence'-things that change together-and using that as a clue that those things belong together," said Sabes. "So we've predicted that you could deliver information to the brain that's entirely novel, and the brain would learn to figure it out if it changes moment-by-moment in tandem with something it knows a lot about, such as visual cues."
According the study findings, the prediction has proven to be correct.
The study has been published in the journal Nature Neuroscience.