Natural neural integration of artificial proprioceptive feedback for effortless prosthetic control

Prosthesis users can control their prosthetic hands, but they cannot feel them. Sensation can be partially restored by electrical stimulation activating the skin in a pattern reflecting prosthesis actions. The aim of this project was to understand how the brain perceives such “artificial” feedback, and how to optimally design it to give the brain the most accurate understanding of prosthesis state. Using a novel method, we found that within minutes of training, the brain effectively substitutes the sense of tingling on the skin with a sense of the task-relevant information (in our case grasp force), to a degree where its perceived reliability exceeds the natural sense of grasp force. Moreover, we identified the stimulation strategy that enabled the optimal perceived reliability. We believe that these findings will enable the design of effective sensorized prosthesis for future users.