According to neuroscientists, new insights into the brain’s plasticity may have implications in neuroprosthetics designed for patients with spinal cord injuries (SCIs), amputations, and other disabilities. Researchers report that the study suggests that through the plasticity, parts of the brain can potentially be trained to do something it normally does not do. A news release adds that the same brain circuits used to learn motor skills can be used to master mental tasks.

Jose Carmena, PhD, University of California, (UC) Berkeley, associate professor of electrical engineering, cognitive science, and neuroscience, co-led the study and articulates its primary goal, “What we hope is that our new insights into the brain’s wiring will lead to a wider range of better prosthetics that feel as close to natural as possible,” Carmena says. 

Carmena also notes that the study’s findings indicate that for patients, learning to control a brain-machine interface (BMI) may feel natural as the patient is learning using the brain’s existing built-in circuits for natural motor control. “…What our study shows is that neuroprosthetic control is possible, even if physical movement is not involved,” Carmena explains.

UC Berkeley researchers report that they used a rat model during the study. In the experiment, the study notes, rats could complete an abstract task only if overt physical movement was not involved. Researchers add that they decoupled the role of targeted motor neurons needed for whisker twitching with the action necessary to get a food reward. The rats were reportedly fitted with a BMI that converted brain waves into auditory tones. To receive the food reward, which included sugar-water or food pellets, the rats were required to modulate their thought patterns within a specific brain circuit in order to raise or lower the pitch of the signal, the news release explains.

In order to allow the rats to associate specific thought patterns with a specific pitch, researchers say they provided the animals with auditory feedback. The researchers’ findings indicate that over a 2-week period, the animals learned that creating a high-pitched tone resulted in a reward of food pellets and a low-pitched tone resulted in sugar water.

The study notes that no food reward was given if the group of neurons in the task were used for whisker twitching, their typical function. The results also indicate that the rats exhibited intentional behavior, varying the amount of pellets or sugar water they received based on their level of hunger or thirst.

Researchers add that they hope the findings translate into a new generation of prosthetic devices that feel natural, the ultimate goal being that patients will not have to, “think too hard to move a robotic arm with their brain,” Carmena says.

Source: UC Berkeley