Using A Brain-Computer Interface to Control Both Arms with the Undamaged Side of a Brain

Achievement date: 

Scientists have demonstrated that one side of a brain can multi-task, simultaneously controlling one arm through a brain-computer interface (BCI) and another through normal neural pathways. The breakthrough arose from the work of a multi-disciplinary team led by researchers at the Center for Sensorimotor Neural Engineering (CSNE), an NSF-funded Engineering Research Center (ERC) headquartered at the University of Washington (UW).


The ability to control two arms with one side of the brain promises to greatly expand the reach of BCI, which had been limited in human trials to demonstrating function in people with spinal cord injury and brain-stem stroke. The number of people with these conditions is small compared to strokes that affect the brain surface and disable one side of the brain. The innovation of using the remaining, functional side of the brain to control both the arm it normally would as well as another through the BCI arose from a collaboration between electrical engineers, neurophysiologists, and rehabilitation researchers.


A monkey learned to play a videogame where he simultaneously controlled brain activity with the BCI and the movements of the opposite hand. The experiment showed that one brain area could effectively differentiate its activity to control the BCI while independently moving the hand naturally controlled by that brain area.

Interestingly, accomplishing the dual-task control did not depend on the type of neurons selected for the BCI. But under certain circumstances, neurons closely related to hand function used more roundabout pathways to achieve the videogame’s goals. Thus, selecting neurons less related to natural hand function may permit enhanced control of a BCI for people recovering from stroke.

In related work, another CSNE team is developing glassy carbon electrodes as an improvement on traditional metal-based electrode implants. The glassy carbon electrodes are more resistant to corrosion and demonstrate greater biocompatibility than metal-based electrode implants, which typically are made from gold, platinum, or titanium to help ensure good conductivity and inertness. The glassy carbon electrodes also are shown to record and transmit clearer, more robust electrical signals.