Artificial intelligence is ushering in a new era of mind reading, with advanced brain scans revealing much of what we're thinking about. Dr. Marvin Chun, Professor of Psychology and Neuroscience at Yale, explains how researchers in his lab are using fMRI and other new technologies to see what's going on in your brain, even as you sleep. This holds great promise for those in persistent vegetative states, even as it raises ethical questions about just who gets to read your mind.