title: Simultaneous and independent control of a brain-computer interface and contralateral limb movement.
abstract: Toward expanding the population of potential BCI users to the many individuals with lateralized cortical stroke, here we examined whether the cortical hemisphere controlling ongoing movements of the contralateral limb can simultaneously generate signals to control a BCI. A monkey was trained to perform a simultaneous BCI and manual control task designed to test whether one hemisphere could effectively differentiate its output and provide independent control of two tasks. Pairs of well-isolated single units were used to control a BCI cursor in one dimension, while isometric wrist torque of the contralateral forelimb controlled the cursor in a second dimension. The monkey could independently modulate cortical units and contralateral wrist torque regardless of the strength of directional tuning of the units controlling the BCI. When the presented targets required explicit decoupling of unit activity and wrist torque, directionally tuned units exhibited significantly less efficient cursor trajectories compared to when unit activity and wrist torque could remain correlated. The results indicate that neural activity from a single hemisphere can be effectively decoupled to simultaneously control a BCI and ongoing limb movement, suggesting that BCIs may be a viable future treatment for individuals with lateralized cortical stroke.
authors.affiliation: Departments of Rehabilitation Medicine, University of Washington, Seattle, WA, USA.
authors.forename: Ivana
authors.initials: I
authors.lastname: Milovanovic
authors.affiliation: Physiology & Biophysics, University of Washington, Seattle, WA, USA; Washington National Primate Research Center, University of Washington, Seattle, WA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Robinson
authors.affiliation: Physiology & Biophysics, University of Washington, Seattle, WA, USA; Washington National Primate Research Center, University of Washington, Seattle, WA, USA; Graduate program in Neuroscience, University of Washington, Seattle, WA, USA; Center for Sensorimotor Neural Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Eberhard E
authors.initials: EE
authors.lastname: Fetz
authors.affiliation: Departments of Rehabilitation Medicine, University of Washington, Seattle, WA, USA; Physiology & Biophysics, University of Washington, Seattle, WA, USA; Washington National Primate Research Center, University of Washington, Seattle, WA, USA; Graduate program in Neuroscience, University of Washington, Seattle, WA, USA; Center for Sensorimotor Neural Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Chet T
authors.initials: CT
authors.lastname: Moritz
keywords: brain-machine interface; hemiparesis; motor cortex; neuroprosthesis; stroke