Brain–Computer Interfaces for Movement

This chapter describes differences between passive and active brain–computer interfaces (BCIs). It explains how active BCIs enable users to move a prosthetic arm or limb, or a computer cursor, and gives them a certain degree of control over these movements. There is shared control between the user and the interface, and this restores the user’s capacity for agency. In normal voluntary bodily movements, one does not have to think about performing them. In BCI-mediated movements, the user must plan how to use the system in activating and directing brain signals to the computer to perform them. There are two intentions: intending to perform an action; and intending to perform it with a BCI. There are two mental acts: activating and directing signals to the computer to produce the motor output. The fact that there are two intentions and two mental acts resulting in a physical movement could motivate a revision of moral and legal criteria of responsibility for BCI users. It could influence judgements of responsibility for actions, omissions, and their consequences.