Lucid Dreaming: Psychophysiological Studies of Consciousness during Rem Sleep

Although we are usually not explicitly aware that we are dreaming while we are dreaming, at times a remarkable exception occurs, and we become conscious enough to realize that fact. “Lucid” dreamers (the term derives from van Eeden, 19 13) report being able to remember the circumstances of waking life freely, to think clearly, and to act deliberately upon reflection, all while experiencing a dream world that seems vividly real (Green, 1968; LaBerge, 1985; Gackenbach & LaBerge, 1988). This contrasts with the usual characterization of dreams as states that typically evince no reflective awareness or true volition (Rechtschaffen, 1978). Lucid dreaming is normally a rare experience. Though most people report having had a lucid dream at least once in their lives, only about 20% of the population reports having lucid dreams once a month or more (Snyder & Gackenbach, 1988). Although most people have experienced lucid dreams, some theoreticians have considered them impossible and even absurd (e.g., Malcolm, 1959). In the absence of empirical evidence, most sleep researchers have been inclined to accept Hartmann’s (1975) “impression” that lucid dreams are “not typical parts of dreaming thought, but rather brief arousals” (p. 74; see also Berger, 1977). Schwartz and Lefebvre (1973) noted that frequent transitory arousals are common during REM sleep and proposed that these “microawakenings” are the physiological basis for lucid dream reports. Although no one has found any evidence for this mechanism, their proposal has been the predominant opinion (cf. Foulkes, 1974) until the last few years.