SLOW MOTION

SLOW MOTION Dani Shapiro (Random House, $23.95) At 20, the author, who was raised in an Orthodox Jewish household, dropped out of college, began an affair with a friend's stepfather, and became an ''actress.'' In other words, she became a kept woman (complete with furs and a cozy Greenwich Village hideaway) and, in her self-disgust, a drunk. Three years later her parents were involved in a car accident that left her mother with over 80 fractures and her father in a coma. While tending to her parents, Shapiro also began, finally, to tend to herself. The author remains notably free of self-pity and rigorous in her scrutiny; she doesn't spare her lover, her family, or herself, yet there's emotion on these pages that is rare among the recent spate of confessionals. The result is a story that isn't perversely voyeuristic, but simply rewarding. A-