Neurological correlates of lucid dreams and out-of-body experiences
Lucid dreaming, or being aware that you are dreaming, has been a hot topic in psychology, neurology and philosophy since at least 1978, when Keith Hearne first recognised the state during his PhD work (see also Celia Green’s 1968 book Lucid Dreams for an earlier study on the phenomenology of lucid dreams). Research into lucid dreaming has especially taken off in the past ten years, with one particular study causing digital cries of “Lucid dreamers have bigger brains!”
The Max Planck Institute of Human Development had just found evidence suggesting that lucid dreamers have greater grey matter than non-lucid dreamers in the anterior prefrontal cortex (aPFC), an area of the brain associated with self-reflection, memory recall, problem solving and metacognition. It is not clear whether lucid dreaming is the cause or effect of this increased grey matter. As out-of-body experiences share some similarities with lucid dreams, it's interesting to look at how these states compare neurologically.
Electroencephalogram (EEG) of subjects during out-of-body experiences (OBEs) has been conducted several times, particularly in the 1970s. Charles Tart’s subject ‘Miss Z’, Stuart Twemlow’s subject Robert Monroe, Janet Mitchell’s subject Ingo Swann, and Joel Whitton’s subject Alex Tanous all showed a flattening of the EEG record during their OBEs. This flattened state was different from sleeping, dreaming, drowsy and waking patterns, but similar to states of deep hypnosis and vivid mental imagery. Tart believed that this may happen between waking and sleeping, or between a (REM) dream and an OBE.
This brings up a lot of questions for my neurologically-ignorant mind, so I asked my friend Rodrigo Montenegro, who is a neuroscientist specialising in sleep medicine, to answer some questions. Rodrigo is researching the neurological correlates of out-of-body experiences, and preliminary findings suggest ground-breaking discoveries (soon to be published).
His team measured the EEG patterns of participants who claimed to be able to induce, at will, the 'vibrational state'. The vibrational state (VS) often precedes an OBE, and involves the feeling of vibrating - without actually physically shaking - either in one part of the body or, usually, throughout the entire body. Previous results indicated that the induction of this state resulted in up to 200 Hz brain waves. The study was put on hold while a new EEG machine was custom built, as not all EEG machines record above 120 Hz. Results from the custom-built machine also indicated that areas of the cortex were showing the high gamma wave band – in some instances reaching over 200 Hz.
These results are certainly intriguing if compared to the state of lucid dreaming, which shows 40 Hz activity in the prefrontal cortex; both states involve high brain activity in the Gamma bandwidth but the VS is more extensive and intense. This is extremely interesting to me as I’ve been studying comparisons between social content in both lucid dreams and out-of-body experiences, so it’s fascinating to see how the two states are expressed in the brain. There are still a lot of factors to be researched in more depth, but for now I want to understand more about what these states could be doing to the brain, and to gain a deeper understanding of terms such as ‘brainwaves’ and ‘grey matter’.
Source: Rodrigo Montenegro 2019
ST: The Max Planck Institute found that lucid dreamers had greater prefrontal cortices, and it has been suggested that this is due to the 30-40 Hz gamma waves in this part of the brain during lucid dreaming. Your study has shown that the vibrational state, often associated with out-of-body experiences, is associated with 200+ Hz in the cortex. Do you think that gamma waves truly stimulate or enlarge the brain? And if so, could the vibrational state lead to a super-brain?
RM: Increased connectivity is more to the point. So yes, it would be normal to see such a condition, I mean an increase in connectivity. Everything you do is associated with neuro-synaptic changes: neurons that bind together over time increase connections. So yes, I would think that an increased capacity to induce the VS would be associated possibly with an increased connectivity of areas associated with the VS.
Our preliminary study of the VS recorded up to 256 Hz to be precise. But this is the raw data, without taking out the EEG artefacts. Raw data are a good way to gauge the potential for an Event Related Potential which we have tried to stipulate in this study; nonetheless even without these artefacts, after cleaning of the data we have seen a very high increase in gamma waves. And indeed, such high gamma waves are equally seen in the prefrontal cortex. In our preliminary tests, we have found that the VS is associated with higher brain activity, in the high gamma range, especially in the frontotemporal cortex (an area associated with conscious self-awareness).
However, we can’t suggest at this stage that this would indicate a larger prefrontal cortex as indicated in the referred study. Even so, the characteristics of the brains of subjects inducing VS have specific and intriguing properties, specifically in their capacity to achieve high gamma. I’m currently working on a theory that suggests that indeed, an increase in gamma band waves are associated with brain health.
ST: So potentially the vibrational state can be associated with neuroplasticity. Maybe I’m jumping the gun here.
RM: So yes, the VS could be associated with an increase in grey matter associated with such areas but not necessarily neuroplasticity. Neuroplasticity is often associated with neural adaptation and the term neuroplasticity infers that another area of the brain is supplying a deficient one, meaning that a specific functional area of the brain is supplementing the work of another, which is deficient or incapacitated. This can be achieved through behavioral training. So, what we see is that people who achieve the VS often have years of training and as such could have induced a higher functional adaptation.
ST: It’s interesting that in popular culture, epilepsy is often associated with genius or creativity. And epilepsy also involves 200+ Hz brainwaves.
RM: Gamma waves increase during ‘Eureka’ moments which have equally binding properties, inducing higher connectivity in functional areas. It is very possible that such levels of gamma waves would indicate a higher level of association of ideas and creativity due to the characteristics of gamma waves. The epileptic relation is more complex to assess; however, it may be theoretically possible to think that some form of epilepsies could end up with neural deficiencies related to the control of such capacities.
[Note: epilepsy is also often associated with shamanism, which in turn is usually associated with out-of-body travel.]
ST: What do you mean by “the characteristics of gamma waves”?
RM: Higher brainwaves, such as gamma, mean higher activity in the brain. Gamma increases the binding or neuroconnectivity between functional areas of the brain. I don’t remember, however, reading any literature suggesting that there is a correlation between gamma and neuroplasticity, although this might be possible. Certainly, what is seen is that gamma increases binding and this is actually one of the current explanations for consciousness, explaining how different areas of the brain entangle together to form consciousness.
ST: Some people are using mild electric shocks to the brain for studying. Is the same principle at work here? So if you’re using certain connections in the brain, could having gamma waves present in that part of the brain potentially strengthen connectivity there?
RM: Connectivity is strengthened through behavioral conditions, not necessarily with gamma. Brain neuromodulation (not electric shocks) which use mild electricity to stimulate the brain increases neuromodulation or inhibition depending on the type of stimulation. But when you are stimulating the brain in this way, yes, you may expect to increase synaptic adaptation and connection. This is known to induce a strengthening of the synaptic connection increasing the neuromodulation effect even an hour after the stimulation.
ST: There is some disagreement about the differences between lucid dreams and out-of-body experiences, the latter of which are associated with the Vibrational State. In summary, what do you think current research on the neurological correlates of these two states suggests in this regard?
RM: I don't think any research has addressed this problem specifically in regards to the phenomenology of OBEs. Current research does not regard OBEs with the extensive phenomenological frame associated with it. It is then easy to misportray OBEs as dissociation or simply as a lucid dream, if such particularities are not taken into account. My ongoing research suggests a phenomenological framework of about 90 specific phenomena. There are no theories, among the many trying to explain OBEs, that take into consideration such phenomena or that have an explanation that can account for them all. Most research only appeals to simple perceptions associated with sensations of OBEs and some only use one criteria such as if the person sensed it was an OBE. That is hardly enough.
The vibrational state is a good example of that reductionism. It has always been considered a hallucination and has never received proper scientific attention. The phenomena as such remained in a scientific apriori. With our research we can scientifically demonstrate that the vibrational state is a neuroscientifically distinctive phenomena with a clear, objective and specific neural state. EEGs do not lie. You can dismiss the phenomena but you can't simply dismiss the data without any explanation. And such a phenomenon is only one out of many without current scientific consideration. Finally, to respond to your question, if the lucid dream is supposed to explain OBEs, science will need to explain these 90 or so phenomena within the neurophysiological context of lucid dreams. Some of these phenomena cannot be explained within the neurophysiology of REM, or the most specific neurophysiology of lucid dreaming.
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This is just an initial outlook of Rodrigo Montenegro’s research, which will go into more depth. In the meantime, you can follow him here.
The implications of the Max Planck Institute’s study, showing increased grey matter in the prefrontal lobe of lucid dreamers, and Rodrigo Montenegro’s ongoing study on out-of-body experiences and the vibrational state are potentially enormous. Montenegro mentioned that the induction of the VS has such broad applications that it was the reason for launching his start-up Gamma Wave Technologies Ltd., which among other things aims to teach people how to induce a high gamma wave state and test such hypotheses through clinical trials. News of these trials to follow.
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