Adam Wilson posted two messages on Twitter on April 15. The first one, "GO BADGERS," might have been sent by any University of Wisconsin-Madison student cheering for the school team. His second post, 20 minutes later, was a little more unusual: “SPELLING WITH MY BRAIN.” Wilson, a doctoral student in biomedical engineering, was confirming an announcement he had made two weeks earlier — his lab had developed a way to post messages on Twitter using electrical impulses generated by thought
