Most of us have seen the classic television trope of a sleepwalker: a person, arms outstretched, staggering about the house as if directed by a video game controller. But what is sleepwalking, exactly ...

Once, years ago, I found myself in an ice-cold bath with no memory of walking to the bathroom or running the tub. Another time, I terrified my friend by leaving our hotel room in the middle of the ...

An hour or two after my school-age son has gone to bed, he sometimes wakes up from a nightmare, walks to my room and mumbles incoherently about what’s scaring him. But he seems off, and I can't get ...