IT IS common knowledge that a day's experiences may be reflected in that night's dreams. As long ago as 1900, Freud1 studied the relationship between waking and sleeping mentation from the then new psychoanalytic point of view. He made the well-known distinction between manifest and latent dream content and systematically elaborated the idea that the manifest dream content draws on both the dreamer's recent and remote experiences. He stressed that "in every dream it is possible to find a point of contact with the experiences of the previous day." He also noted that such still active daytime mentation (the "day's residue") tends to appear in dreams not unchanged, via incorporations, but rather in a disguised manner in the form of transformations. Subsequent psychoanalytic studies of dreaming have elaborated on Freud's ideas about dream formation. A handful of experimental studies have also focused