For the first time in humans, researchers use brain surface stimulation to provide 'touch' feedback to direct movement. In the quest to restore movement to people with spinal cord injuries, researchers have focused on getting brain signals to disconnected nerves and muscles that no longer receive messages that would spur them to move. But grasping a cup or brushing hair or cooking a meal requires other feedback that has been lost in amputees and individuals with paralysis -- a sense of touch. The brain needs information from a fingertip or limb or external device to understand how firmly a person is gripping or how much pressure is needed to perform everyday tasks.
Now, University of Washington researchers at the National Science Foundation Center for Sensorimotor Neural Engineering (CSNE) have used direct stimulation of the human brain surface to provide basic sensory feedback through artificial electrical signals, enabling a patient to control movement while performing a simple task: opening and closing his hand. It's a first step towards developing "closed loop," bi-directional brain-computer interfaces (BBCIs) that enable two-way communication between parts of the nervous system. They would also allow the brain to directly control external prosthetics or other devices that can enhance movement while getting sensory feedback.