Playing the piano with a robotic third thumb: Assessing constraints of human augmentation

Abstract

Contemporary robotics gives us mechatronic capabilities for augmenting human bodies with extra limbs. However, how our brains and bodies pose limits on such augmentation is an open question. We developed Supernumerary Robotic 3rd Thumbs (SR3T) with two degrees-of-freedom controlled by the user’s body to endow them with an extra contralateral thumb on the hand. We demonstrate that a pianist can learn to play the piano with 11 fingers within an hour. We then evaluate 6 naïve and 6 experienced piano players in their prior motor coordination and their capability in piano playing with the robotic augmentation. Intriguingly, individuals’ augmented performance did not depend on prior piano experience but could be predicted by our new custom motor coordination assessment, the Human Augmentation Motor Coordination Assessment (HAMCA) performed pre-augmentation. Our work demonstrates how supernumerary robotics can augment humans in skilled tasks and that individual differences in their augmentation capability are predictable by their individual brains’ motor coordination abilities.