The single-mindedness and isolation of dreams.

Dreams are descirbed as "single-minded," meaning that they tend to be unaccompanied by other, simultaneous streams of thought and imagery. Four manifestations of single-mindedness are discussed: (1) the absence of a reflective awareness that one is dreaming while the dream is in progress; (2) the absence of alternative images and thoughts while attending to the primary dream content; (3) the tendency for dream content to stay on a single thematic track; (4) the absence of a set to remember the dream while it is in progress. This isolation of dream content, from other thought systems is then considered as but one manifestation of a more generalized relative isolation of dream content, which includes isolation from presleep stimuli, contemporaneous stimuli, organismic state, and autonomic and motor activity. Some of the implications of dream isolation for dream psychophysiology and theories of dreaming are outlined.