Photo looking down on a brain interface human test subject. The subject, a young woman, is wearing a tight-fitting cap with electrodes embedded in it, and a flat cable emerging from the back of the cap and connecting to the test equipment (not shown). The subject has her hands folded in her lap and is looking at a computer screen, on which we can see a large dot representing the cursor position and a larger box on the side of the screen to the subject’s right. The screen is not fully visible from this angle.