The effect of time of night on wake–dream continuity.

Research has demonstrated a number of time-of-night and stage-of-sleep differences
in dream content, such as that dreams from later in the night are longer, more emotional,
and more bizarre. It was hypothesized that time of night may therefore demonstrate
differences in the continuity of waking life into dreams. Participants (N � 16) were
systematically awoken 4 times a night for 2 nights and rated their dreams for wake-
–dream continuity on a number of dimensions. It was found that time of night affects
wake–dream continuity overall, particularly showing an increase of bizarreness over
time; that there were more references to waking-life media in the early than late night; that
there were more references to waking-life activities and objects in the late than early night;
and that the ways in which different types of wake–dream continuity correlate (such as
continuity with present, past, and future waking life) change from the early to the late
night. No stage-of-sleep effects were able to be demonstrated. The results support the
hypothesis that time of night affects wake–dream continuity.