A Continuum of Consciousness in Sleep
What is Meditation? An Technique to Access Pure Consciousness.
Physiological parallel’s between lucidity and meditation
Physiological parallel’s between lucidity and meditation also exist. Except that the individual is awake, depth of somatic arousal during meditation has been characterized as equivalent to or deeper than that of light sleep (Kesterson, 1985) but is not the same as light sleep (West, 1980). However, REM sleep shows increases in oxygen consumption and heart rate over stages 1 and 2 NREM and lucid REM is significantly higher on these dimensions than nonlucid REM (LaBerge, Levitan, & Dement, 1986; LaBerge, 1985; 1988). This lucid somatic arousal would seem to argue against the lucid dreaming-meditation parallel. LaBerge (personal communication, June, 1987) has pointed out that the continued somatic arousal after the eye movement signal which he has found could be an artifact of demand characteristics. That is, his subjects are typically told to signal when they know they are dreaming and then to do a predesigned task; active engagement in a dream task with consciousness could keep the system somatically aroused.
A study of ours (Gackenbach, Moorecroft, Alexander & LaBerge, 1987) sheds some light on this apparent discrepancy. We had a long term meditator who during meditation showed physiological signs of transcending correlating with his self reports. This individual claimed that he was conscious of his true state throughout his sleep cycle. That is, he knew he was sleeping and sometimes dreaming during the entire night. He characterized his ability as witnessing sleep which you will recall is a way of describing the experience of pure consciousness. This ability and its stabilization is said to be a result of the regular practice of meditation (Alexander, Boyer & Orme-Johnson, 1985). In the sleep laboratory this meditator was able to signal with prearranged eye movements that he knew he was dreaming/sleeping during REM, Stage 1 and Stage 2 sleep. Interestingly, and in line with the present hypothesis, he showed physiological arousal around the eye movement signal but contrary to the data of LaBerge et al. (1986) he rapidly returned to quiet somatic levels shortly thereafter. With at least this one subject signaling was somatically arousing but his self-reported continued consciousness in sleep was not. This study suggests that as lucid dreaming unfolds to witnessing dreaming somatic arousal decreases and the equation of consciousness in sleep to states desired by the practice of meditation becomes firmer.
Further supporting the meditation-lucidity link is a finding with the Hoffman or H-reflex, an electrically evoked monosynaptic spinal reflex which has been viewed as an indicate of the flexibility of central nervous system response. Brylowski (1986) found greater H-reflex suppression associated with lucid REM sleep than with nonlucid REM sleep. H-reflex suppression is thought to be a key indicate of the presence of the REM state of sleep as one is paralyzed from the neck down. This body paralyses does not occur during any other time of the sleep cycle nor while awake. This finding is conceptually in line with studies by Dillbeck, Orme-Johnson, and Wallace (1981) and Haynes, Hebert, Reber & Orme-Johnson (1976). Dillbeck et al. found greater H-reflex recovery indirectly associated with an advanced form of meditation practice while Haynes et al. note positive correlation’s between H-reflex recovery and clarity of experience of the transcendental state while meditating. Enhanced H-reflex suppression in REM and recovery in waking both indicate a nervous system which is functioning maximally in accord with the needs of the state of the organism.
The EEG work with dream lucidity is unfortunately fairly limited at this point with the bulk having been done by Ogilvie, Hunt and associates (Ogilvie, Hunt, Sawicki & McGowan, 1978; Ogilvie, Hunt, Tyson, Lucescu & Jeakins, 1982; Tyson, Ogilvie & Hunt, 1984; Ogilvie, Vieira & Small, 1988; Hunt & Ogilvie, 1988). In this series of studies they sought to demonstrate the lucidity-meditation connection by examining alpha waves in lucid and nonlucid REM. Reviews of the EEG and meditation literature have fairly consistently pointed to the association of alpha with meditation (West, 1980; Taneli & Krahne, 1987; Wallace, 1986). The Ogilvie and Hunt group found, consistent with the meditation literature, variations in alpha as a function of stage of lucidity. Specifically, they found increased alpha in prelucid REM periods and early in lucidity and have likened this to the access phases of waking meditation. Similarly, West (1980) and Taneli and Krahne (1987) have summarized the EEG and meditation literature for power measures and note changes as a function of stage of meditation. Both reviewers agree that at the beginning and at the end of meditation increases in alpha are observed. Later theta occurs, often intermixed with alpha, and at the “transcending” or “samadhi” phase bursts of beta occur.
West (1980) has pointed out that a more sophisticated examination of EEG changes in meditation should include the investigation of EEG coherence (COH). The relationship of this variable to meditation has been most extensively investigated in the Transcendental Meditation research literature (for a review see Orme-Johnson, Wallace, Dillbeck, Alexander & Ball, in press; Wallace, 1986) and offers a unique potential for identifying EEG associations to types of consciousness during sleep.
In a review of the coherence literature, French and Beaumont (1984) concluded that TM has been shown to increase COH especially in the alpha and theta bands relative to eyes closed, resting conditions. This work has been carried further to examine the relationship of COH to specific meditation experiences. Farrow and Herbert (1982) reported that experiences of “transcending” during TM were associated with alpha, theta and beta global COH while Orme-Johnson et al (1977) and Orme-Johnson and Haynes (1981) found total alpha EEG coherence related to experiences of transcending during meditation. The bulk of the variance for these findings is from frontal leads.
In a recent paper (Gackenbach, in press) I have argued that in terms of frontal leads, REM is interhemispherically coherent in the theta range relative to NREM, thus making it the state in which meditation like experiences (lucidity) would be most likely to occur. Several investigators have shown that lucidity primarily emerges out of REM (see LaBerge, 1988, for a review). Furthermore, Armitage, Hoffman and Moffitt (in press) report that high dream recallers show a greater continuity for a measure conceptually similar to EEG coherence in transition from sleep to waking. Thus individuals who frequently remember their dreams are accessing information from a coherent state of brain functioning by remaining in some sense in that state. One of the most robust findings in both the individual difference (Snyder & Gackenbach, 1988) literature on dream lucidity is the association of high dream recall to lucidity frequency. Lucid dreamers in general are high dream recallers so they should show more COH at the state transition to waking.
But will lucid dreams themselves be higher in COH. In Gackenbach’s (1988) work with self evaluations of the recallability of lucid versus nonlucid dreams the former are continually perceived as significantly easier to remember. Although one might argue that the phasic nature of lucid dreams might be responsible for their increased recallability, Pivik (1978) points out that dreams recalled from phasic versus tonic REM do not differ in recall. Indeed the “tonic” consciousness of the dreams reported by the witnessing TM meditator in the study just reported (Gackenbach et al., 1986) were rated as highly recallable by the subject if phenomenologically quiet (Gackenbach & Morrecroft, 1987).
More directly, in pilot data LaBerge looked at EEG coherence twice. In his dissertation (LaBerge, 1980) he had only central EEG leads and found no COH differences as a function of lucidity. More recently (LaBerge, personal communication, June, 1988) he compared a 5 minute lucid dream during REM to the 15 minutes of REM prior to the onset of dream consciousness in one subject. Looking at interhemispheric EEG coherence measured at the parietal lobes, he found an increase in COH during the lucid phase of REM for the alpha frequency. Although these findings are highly preliminary they are in the direction expected. That he found increased COH from the parietal leads is interesting as the central role of visual-spatial functioning, associated with this area of the brain, has been strongly implicated in our work for both lucid dreamers (Snyder & Gackenbach, 1988) and lucid dreams (Gackenbach, 1988). Further, this was the location of interhemispheric alpha COH reported by O’Connor and Shaw for field independent individuals, a perceptual style characteristic of high dream recallers, lucid dreamers, and meditators.
Clearly on several levels of analyses dream lucidity parallels waking meditation. Although lucidity can and does emerge spontaneously in nonmeditating populations, the average frequency of such experiences is considerably less than that in meditating adults (Gackenbach, Cranson & Alexander, 1986; 1989).