The narrow definition of lucid dreaming is having a dream wherein you know you are asleep and dreaming. But, there may be a spectrum of related phenomena. For example, there is also the situation where you think you’re awake, but you’re actually asleep, and you discover this only when you really wake up. Then, there are sleep time OBEs and visitations from non-physical beings.
This raises the question of whether these experiences are reality or fantasy. My best understanding at this point is that there are sleep time experiences that are somewhat veridical, ie external, shared reality; and some that are purely fantasy, ie a psychological product of your own imagination. In fact, they may always be a blend. It seems like all psi experiences, no matter how veridical – remote viewing, NDEs, OBEs, clairvoyance, etc. – are experienced via your own psychological repertoire, so they all have some element of idiosyncratic interpretation mixed in.
Still, I want to emphasize that there is a lot of evidence for real, veridical, evidential visitations, OBEs, and other types of experiences that happen while we are asleep-ish.
Apparently, it has been theorized that there are different sub-types of REM sleep, and that lucid dreaming occurs during a particular type. There is still disagreement about what defines this particular type of REM sleep. It might be increased alpha; increased parietal beta; increased frontal and fronto-lateral gamma, or something else.
The neural substrate also may be different depending on whether the lucid dreaming is spontaneous or induced.
In some very small studies, spontaneous lucid dreams have shown increased parieto-occipital beta and “global increase in theta phase – gamma amplitude coupling” (Huh? I think this means that the theta waves modulated the gamma waves, and that they’re showing a tendency to occur together. In other words, synchronization occurred.) This may be a sign of increased visual attention and executive memory processing.
In other small studies, induced lucid dreaming has shown increased frontal gamma or increased right parieto-temporal gamma.
Mota-Rolim et al. (2010) propose that the different EEG readings in different lucid dreams may mean that there are different ways to enter a lucid dream. Pluralism strikes again! I like this! But they’re approaching the question from a purely biological point of view, with no interest in the possibility of consciousness existing outside the brain or in psi. I wonder if the different EEG readings might also mean something about the veridicality of the experience. IOW, are you accessing your memories and creating your own internal video game, or are you accessing your memories *and* an external, veridical information source?
Hobson (2009) thinks that lucid dreaming may be a state that is an amalgam of the waking and the dreaming states – “Lucid dreaming is characterized by more 40 Hz power [gamma] than non-lucid dreaming, especially in frontal regions. Since it is 40 Hz power that has been correlated with waking consciousness in previous studies, it can be suggested that enough 40 Hz power has been added to the non-lucid dreaming brain to support the increase in subjective awareness that permits lucidity but not enough to cause full awakening (p. 42).”
Again, Hobson appears not to be interested in psi or the possibility of consciousness existing outside the brain. He and many others think it’s possible that gamma is the signature of consciousness being created within the brain. In other words, the presence of gamma in several different locations in the brain at the same time is what creates the experience of consciousness.
However, I am going to speculatively interpret his findings in light of the evidence that gamma waves also correlate with psi in general, and even more so with conscious psi. Don (2010) reviews several studies that suggest that, although alpha and theta may be related to psi, gamma is an even stronger predictor. Don also noticed an interesting possible field effect related to the presence of gamma. Brazilian psychic surgeons and UFO abductees unwittingly made random event generators non-random near themselves, while they were in altered states that showed a lot of gamma. This field effect might be what made it possible for the surgeons to cut into someone with a rusty saw without much bloodshed or trauma!
It’s interesting that gamma has been linked with general consciousness in the non-parapsychological community and with psi in the parapsychological community. This hints again at the possibility that consciousness *is* psi, along the lines of Carpenter’s First Sight model (see 6 Jan 12 blog post).
So, to summarize the main hypotheses of this post --
Different EEG profiles may correlate with the degree of veridicality of a lucid dream, ranging from pure fantasy to highly evidential, with a full spectrum in between.
Gamma brainwaves may create a field effect outside the body, and this may be a clue to how lucid dreamers can access veridical, transpersonal aspects of reality such as deceased loved ones.
Sources (thanks to Gerd Hövelmann) –
Don, N.S. (2010). Electrical activity in the brain and the extraordinary mind. In “Mysterious minds: The neurobiology of psychics, mediums, and other extraordinary people,” Krippner, S. & Friedman, H.L., eds. Praeger.
Hobson, J.A. (2009). The neurobiology of consciousness: Lucid draming wakes up. International Journal of Dream Research, 2, (2), 41-44.
Mota-Rolim, S.A., Erlacher, D., Tort, A.B.L., Araujo, J.F., & Ribeiro, S. (2010). Different kinds of subjective experience during lucid dreaming may have different neural substrates. International Journal of Dream Research, 3, (1), 33-36.