Around the early 2000s, research on primate Brain-Machine Interface (BMI) began to emerge. Notably, one study conducted in 2002 by Mijail D. Serruya et al. demonstrated that monkeys could move a computer cursor using BMI. The researchers first had the monkeys use a joystick while 100 electrodes were implanted in the monkeys’ motor cortex. While the monkeys moved the joystick to follow a red target, the researchers monitored their brain activity to determine the brain signals that corresponded with specific arm movements. Then, the researchers were able create a program, which monitored the monkeys’ brain signals and moved the joystick accordingly, based on the data they collected. They found that using this BMI, monkeys were able to move the computer cursor just by thinking.
Another study conducted by the Department of Neurobiology in Duke University in 2003 revealed that monkeys could reach and grasp objects using a robot arm. The monkeys were trained to use the robot arm for a reaching, hand-gripping, and reach-and-grasp task. Initially, the monkeys moved their arms to move the robotic counterpart. However, they soon found that this was not necessary. Thinking about moving the robotic arm, like the monkeys who simply needed to think about moving the computer cursor, was enough. With time, the monkeys’ performance improved. The researchers found that there were short-term and long-term changes in the monkeys’ cortical areas, which allowed them to adapt to the robotic arm.
The significance and applications of this research are extensive. In the past, researchers attempted to develop a treatment for spinal cord injuries which involved reforming damaged nerve fibers. However, the main setback of this method was that animals receiving this treatment still had trouble reaching and grasping. This could have been due to these motor tasks requiring fully functional nerve fibers, since many neural populations in the brain must be involved. BMI was an attractive alternative because it allowed patients perform motor tasks without a fully healed spine. While the spine serves an important role as the conduit for the brain’s “orders,” BMI allows patients bypass this requirement, since a robotic substitute receives the brain’s orders rather than the patient’s limbs.
As of now, research in BMI has advanced to the point where paralytic patients have been able to reap its benefits.
Carmena, J. M., Lebedev, M. A., Crist, R. E., O’Doherty, J. E., Santucci, D. M., Dimitrov, D. F., Patil, P. G., Henriquez, C. S., & Nicolelis, M.A. (2003). Learning to Control a Brain-Machine Interface for Reaching and Grasping by Primates. PLoS Biology, 1(2). 193-208. https://doi.org/10.1371/journal.pbio.0000042
Myers, D. G. (2014). Psychology: Tenth Edition. New York: Worth Publishers.