Berliner, whose work has included "Nobody's Business" (1996), about his father, and "The Sweetest Sound" (2001), about his name, has the gift of addressing intimate subjects and making them universal. Nowhere has he done this better than with "'Wide Awake," in which he uses dazzlingly edited movie outtakes, self-portraiture, TV commercials, homemovies, in-her-face footage of his comfortably sleeping wife (who, of course, wakes up) and the advice of sleep specialists, all in an effort not just to figure out why he can't sleep, but to determine what sleep means.

Whether expressing his sleep-deprived anguish directly into the camera or having his head virtually wrapped in contacts and wire so his rest patterns can be studied, Berliner is always operating from a position of bemusement. He doesn't know why he can't sleep, but suspects it is rooted either in his long years as a night-owl filmmaker, or as a child whose parents' arguments made him associate the night with turmoil. There are no solid answers, but the director's obsessiveness about the subject -- his mother, his sister, his wife and even he all get fed up eventually -- is a consistently humorous business.

Both the editing -- Berliner's work in this department is first-rate -- and the polished look of the film help keeps the viewer engaged; no one will be nodding out at "Wide Awake."

The question Berliner asks that sums up his quandary is whether he doesn't sleep because he's a night owl, or he's a night owl because he doesn't sleep. But during a tour of his work space, we see the fastidious organization of his materials: Boxes of movie footage, boxes of newspaper clippings, snippets of sound effects, unknown people's derelict homemovies that he might need to augment his film work at a moment's notice. Such attention to details seems to indicate a mind that sprints while others limp, and which needs not to run before it can walk and rest and tumble into dreams.

Camera (color, HD), Ian Vollmer; sound, Steve Beganyi, John Haptas, John Kushak, Ramon Rivera-Moret, Chris Ward; associate producer, Natalya Trifonova. Reviewed at Sundance Film Festival (competing), Jan. 22, 2006. Running time: 90 MIN.