We can never prove that the consciousness of somebody at some time might have left their body in some way and gained access to knowledge otherwise unavailable. It’s impossible to prove a negative. On the other hand, the evidence that this has ever happened is virtually non-existent despite the anecdotal accounts that circulate and recirculate through papers, books, and videos.

I’m talking about out-of-body experiences (OBEs) and the special cases of out-of-body of experiences that occur near death (NDEs). There is no disputing these experiences occur. Psychologically healthy, normal people do on occasion have the experience they are outside their body. Some people have them frequently and a few can produce the experience on demand. The prototypical OBE account involves having the sensation of leaving the body and staring down at their physical body from an above position frequently near the ceiling. The NDE may or may not include an OBE but will usually include additional experiences, such as traveling through tunnels, meeting dead relatives, life review, and meetings angels. The claimed veridicality of the OBE portion of the NDE is frequently used as supporting evidence that we have a consciousness that persists after death. While NDEs take place in situations involving extreme bodily stress, frequently cardiac arrests, overall there is considerable overlap between both phenomena.

This is the subject of Seeing Myself: The new science of out-of-body experiences by Susan Blackmore. The book covers not only the historical research of OBEs but importantly covers a great deal of modern neuroscience regarding them. Despite the widespread mystification of these experiences in many quarters, we are surprisingly close to understanding in a scientific way what exactly is happening in the brain during them. This research begins to shed light on how we create and maintain our sense of self.

Blackmore herself is uniquely qualified to write this book. Originally a parapsychological researcher, she actually had a significant OBE that drove years of effort on her part to demonstrate the reality of paranormal phenomena. After years of research and examination of evidence, she found herself forced to conclude there was no evidence for any of it. Despite this change in views, she has not transformed into a cynical materialist scientist. She considers herself a neutral monist, which means she thinks there might be an ultimate reality but we can’t be sure exactly what it is made of. Additionally, she has spent decades in training in various spiritual traditions, primarily Zen, and is a leading proponent of secular spirituality.

Blackmore’s start and end points parallel closely my own thinking on this subject. Originally a believer in the paranormal, I once did a high school project that tried to replicate some of J. B. Rhine’s experiments. My results, much like Rhine’s, were almost off-the-chart in statistical significance. I’m quite certain now that my controls were inadequate and likely even my understanding of the statistics was wrong. These seems to be endemic problems in the field, although probably not quite as acute as in my efforts. As the years have passed, I’ve grown increasingly skeptical on the paranormal until now I am much in the same place as Blackmore. Despite this view, I continue to believe there is some value in spirituality, some significance to what seems like the miracle of consciousness itself.

Blackmore’s book covers the gamut of the out-of-body experiences. Actually there are four types of distortions of self and body image that seem to arise from various types of uncontrolled firings and misfirings in different parts of the brain. The classical out-of-body experience involves the sensation of a self disconnected from the physical body that may or may not have a body itself (usually called the “astral body” in the classical literature on the subject). Autoscopy is when a person in his/her own body has the hallucination of seeing his/her own double. Heuautoscopy is much like autoscopy but the person has the feeling of being in his/her body but also being in the body of a double or sometimes in multiple other bodies. The simplest and possibly most common form of distortion is a feeling of a presence. While possibly subject to other interpretations, Blackmore thinks the presence that is felt is actually a distorted image of one’s own self that is sensed to be behind or surrounding the body.

The feeling of presence can be somewhat reliably reproduced with Michael Persinger’s God helmut that provides magnetic stimulation to the temporal lobes. The classical OBE and various other body distortions can be reproduced by stimulating the temporoparietal junction (TPJ). The TPJ is the point where the temporal lobes on each side of the brain and parietal lobe at the back of the brain meet. Blackmore writes that it is “deeply implicated in building up our sense of self”. Wilder Penfield working with epileptics induced an OBE by stimulating the area and Dirk De Ritter replicated the phenomenon in 2007 while trying to cure a man of tinnitus.

Blackmore’s theory is straightforward. OBEs are the result of uncontrolled firings in various neural circuits that are responsible for our body image and sense of self. These are primarily in the temporal lobe and TPJ. They can be induced by direct stimulation in experimental settings, caused by lesions and other abnormalities in the brain, or triggered by various drugs or other stresses, such as anoxia during cardiac arrest. Uncontrolled firings in the visual and auditory context can also account for reported noises and tunnel travel associated with NDEs and OBEs.

Let’s suppose Blackmore’s theory, even in incorrect in certain details, is broadly correct. Could it still be possible that consciousness can in some way exist outside of the body? Perhaps the neuron firings are simply correlates of consciousness outside the body. Neurons fire when we see an apple hanging from a tree. Maybe they fire, but fire differently, when our consciousness is perceiving something outside the body.

What would be the evidence? This is where we come to the point that we can’t disprove it hasn’t ever happened but we can’t find any evidence for it either.

In all of Blackmore’s survey of classical OBE experience – Sylvan Muldoon, Oliver Fox, Robert Monroe – there is no account of obtaining knowledge during astral projection that is sufficiently specific or that cannot to be accounted for in other ways. What’s more, the OBErs in their own accounts acknowledge getting a significant amount wrong. Some have developed theories about how and why the astral world is different from the physical world to explain why what they see in the astral world doesn’t match the physical. With NDEs, we find the same. She surveys some of the most promising cases – Pam Reynolds and Maria and the shoe – and finds no conclusive evidence. What clouds many of these cases are the possibilities for false memories. People may merge information gained before or after the NDE with the NDE itself. In other cases, people may simply be awake or aware enough to gain information about what is happening to them during resuscitation. Prospective studies, such as the AWARE project, haven’t turned up anything either. These studies involve seeding operating rooms with images and messages that can only be seen from the ceiling. If someone has an NDE and can report the message, it would be close to conclusive proof of veridical out-of-body experience AWARE only produced two NDEs and only one seemed to have an experience outside the body, but unfortunately it occurred in an OR that didn’t have an image or message. Even the main author of the study says the report of that one person wasn’t conclusive. What the single individual reports doesn’t seem exceptional and could have been information gathered before or after the NDE or even during the resuscitation.

The NDE accounts floated in books and through the Internet frequently carry the claim that the NDE with veridical experience occurred while the brain was dead – that is, there was no detectable brain activity. Taken literally this can’t be true. If the brain is completely dead, the person is dead. They can’t be resuscitated. Even with people near brain dead, in most cases, there is no way to verify there is no electrical activity because people undergoing resuscitation or even operations are not connected to sensitive enough equipment to verify there is no activity. Nevertheless, an experiment on mice demonstrated that the dying brain is still active. Even more to the point, an experiment on humans who were terminally ill and had life support withdrawn demonstrated the same thing.

In each case, loss of blood pressure, as monitored by indwelling arterial line, was followed by a decline is BIS/PSI activity followed by a transient spike in BIS/PSI activity that approached levels normally associated with consciousness.

We further speculate that since this increase in electrical activity occurred when there was no discernable blood pressure, patients who suffer “near death” experiences may be recalling the aggregate memory of the synaptic activity associated with this terminal but potentially reversible hypoxemia.

These spikes are temporally associated with the loss of measurable blood pressure, and immediately after the spike, the BIS/PSI signal drop to zero and the patient is soon pronounced dead. The BIS spikes last for a few minutes at maximum, but usually last between 30–180 seconds.

https://www.liebertpub.com/doi/10.1089/jpm.2009.0159

It would be a comfort to many, I’m sure, if our consciousness could exist outside our bodies and survive death. Unfortunately there doesn’t seem to be really any evidence for it.