The first book to recognize the scientific potential of lucid dreams was Celia Green's 1968 study Lucid Dreams.[5] Green analyzed the main characteristics of such dreams. She reviewed previously published literature on the subject, and incorporated new data from subjects of her own. She concluded that they were a category of experience quite distinct from ordinary dreams, and predicted that they would turn out to be associated with rapid eye movement sleep (REM sleep). Green was also the first to link lucid dreams to the phenomenon of false awakenings.

(http://en.wikipedia.org/wiki/Lucid_dream)