[Image]
IN MAY 2011 I EXPLORED the idea of afterlife, and précised some explanations for the ubiquity of beliefs in life after death. In June I outlined a taxonomy of afterlife beliefs, showing that most are variations on two themes, and stem from the same kinds of observations. In this post I want to look at an explanation put forward by Thomas Metzinger for the origin of belief in a soul - i.e. some conscious aspect of 'us' that is not tied to the body. [1] Obviously this subject is closely allied with the theme of life after death since in order to have post-mortem survival some part of us must survive the death of the body.

Those familiar with Metzinger will know that he has had a number of out-of-body experiences (OBE). In his paper he outlines the phenomenology, psychology and neural correlates of OBEs. He attempts to understand these from his own representationalist point of view. Metzinger's view is that the phenomenon of selfhood—the sense of being a self with first person perspective and agency—is related to a sophisticated self-model sustained in the brain. Reality is modelled by our brains in such a way that we do not know we are interacting with the model, except in exceptional circumstances such as brain injury which disrupts the model. Our 'self' is part of the model related to monitoring our own responses to the reality model. But again we experience our 'self' as real, not as a model. In his terms we are all naive realists with respect to our self-models. If one is not familiar with Metzinger's self-model I would recommend reading up on it, and not relying on my very brief summary which can hardly do it justice.[2]

OBE's are often associated with trauma—accidents, epileptic fits, brain injury—but some healthy people have them as well, sometimes in the waking state. They also occur in the dream state, or in the pre-waking state accompanied by sleep paralysis. OBEs are really a cluster of phenomena and that makes it hard to give a single representative example: but the common factors are that one sees oneself and one's surroundings, but feels oneself to be separate from one's physical body, or floating. In the OBE the locus of thought and identity is experienced as being outside the body, while the body and thoughts are still identified as 'mine'. This distinguishes it from phenomena such as depersonalisation and derealisation. Interestingly OBEs can also be artificially induced by direct brain stimulation, or using trans-cranial magnetic stimulation. The part of the brain concerned is the angular gyrus which is on the temporo-parietal junction - where the temporal and parietal lobes of the neo-cortex meet. Put simply if we pass a tiny electric current through the angular gyrus and there is an instantaneous out-of-body experience, switch it off and the OBE ceases.

Metzinger interprets the phenomena of OBE in terms of simultaneous but integrated self models. The first self-model is rooted in bodily sensations: muscle tension, inner ear balance information, the sense of touch etc. The second is primarily visual. Normally these two streams of information are integrated into a single self-model, but in the OBE for whatever reason the result is two self-models. The primary self-model, the one which the subject identifies with as the locus of their ego, is the felt sense of the body, though typically without the sense of weight from gravity which leaves the person with a floating sensation. The visual self-model is functional but not integrated with the felt sense allowing the sense that the subject is not "in" their body. In the OBE the subject will experience themselves as located in an ethereal body rather than as disembodied. Sometimes one simply floats, but frequently one has more or less agency and can decide to move about. This used to be called "astral travelling".

Metzinger describes his own OBEs in his book The Ego Tunnel: The Science of the Mind and the Myth of the Self[Image]. He does not doubt the phenomenological accounts of OBE, however he seeks to explain the OBE from his representionalist point of view, which is based on the observations of neuroscience. Metzinger is particularly interested in disorders like phantom limb syndrome, but also in ways in which the brain decides what is part of it's body and what isn't. For instance in virtual reality experiments subjects can have virtual OBEs where they experience a virtual body projected as separate from them physically in space as their own body. Alok Jha, science journalist, likened this to the movie Avatar where people 'inhabited' specially grown alien bodies. Our sense of being embodied, in our own physical body, is a simulation and it can be disrupted in many ways. If it were not a simulation then explaining phantom limb syndrome or the rubber hand illusion would be very difficult to explain.

The main phenomena the subject in an OBE will experience is that their thought processes are taking place separately from their physical body. Metzinger speculates that OBEs might be good candidate experiences for the origin of ideas about the soul. As he says:
For anyone who actually had [an OBE] it is almost impossible not to become an ontological dualist afterwards. In all their realism, cognitive clarity and general coherence, these phenomenal experiences almost inevitably lead the experiencing subject to conclude that conscious experience can, as a matter of fact, take place independently of the brain and body. (p.78) We are all what Metzinger calls 'folk phenomenologists'—we all interpret our own experiences. On the whole we clearly do a good job of this. But when we have unusual experiences such as hallucinations, sleep paralysis, OBE, or even meditative experiences, we tend not to do such a good job. Although Metzinger does not say so, we are powerfully conditioned by a number of other factors which reinforce the ontological dualism. Here our predisposition to believe in life after death comes to the fore. This in turn is reinforced by our strong Theory of Mind: our ability to project consciousness not only into other humans, but into animals, trees, and even inanimate objects. The Theory of Mind is fundamental to our humanity, without it we would be incapable of empathy or relating to other people. But we are apt to see consciousness, and conscious agency where there is none. Particularly in the dead. If we combine this with an OBE or some other kind of experience which shifts the apparent locus of thought out of the body, such as a lucid dream, then ontological dualism might seem incontrovertible. Clearly some form of dualism is present in almost every afterlife belief, including Buddhist rebirth. It's impossible to posit post-mortem survival (let alone post-mortem memory) without implying, however subtly, an entity which survives separate from the body.

It's important to note that Metzinger is making conjectures here. He is taking the evidence and putting together plausible narratives to account for them. His representationalist explanation of consciousness is highly plausible, and appears to be a useful way of thinking about consciousness and especially self-consciousness. It is powerfully demystifying and disenchanting. It emerges from trying to explain observations from neuroscience, particularly the way the sense of self breaks down. These observations are intriguing, but more work must, and is, being done. And this is crucial difference between science and religion - in science we rigorously test theories hoping to prove them wrong (which is how a scientist gains kudos!)

If Metzinger is right, and I think his suggestion is entirely plausible, then we can see that this idea of being able to separate mind and body feeds into the powerful complex of ideas about post-mortem survival. The belief in an afterlife no longer seems so strange or strained. It's not only a psychological fantasy, but emerges to some extent from our experience of the world - or at least the experience of some of us. Afterlife beliefs are extremely persistent in the face of scientific rationalism, and my exploration of such beliefs has, to some extent, shown why they might seem plausible and preferable to the alternative. Metzinger remarks that trying to destroy a person's deeply held belief in the afterlife has ethical implications. In attempting to undermine a person's belief system we may be doing them a violence. It's all very well to debate the facts such as they are, but as self-aware beings we have an obligation to try to relate to people first and foremost on the basis of empathy. We may simply have to acknowledge that some people will be eternalists no matter what facts we present, because our version of the facts seem implausible compared with the alternative. I don't think this is a problem as long as what they believe is not causing them to be unkind or prevents them from relating on the basis of empathy.


~~oOo~~

Notes Metzinger, Thomas (2005) 'Out-of-Body Experiences as the Origin of the Concept of a "Soul".' Mind & Matter Vol. 3(1), pp. 57–84. http://www.philosophie.uni-mainz.de/metzinger/publikationen/OBE_M&M_2005.pdf Fortunately Metzinger himself has provided an introduction: Scholarpedia. Self models. See also his book: The Ego Tunnel: The Science of the Mind and the Myth of the Self[Image]. I précised Metzinger's lecture on the first person perspective in April 2011. I would also recommend reading Antonio Damasio's book: The Feeling Of What Happens: Body, Emotion and the Making of Consciousness[Image] which gives an account of how self-consciousness might emerge from modelling body states in the brain.
See also 'Man with schizophrenia has out-of-body experience in lab, gains knowledge, controls his psychosis.' via Not Exactly Rocket Science. 1 Nov 2011. 'The Temporal Parietal Junction and OBEs.' How Stuff Works. 'The Out-of-Body Experience: Disturbed Self-Processing at the Temporo-Parietal Junction.' Neuroscientist. February 2005 11(1) 16-24. [abstract] Blanke, Olaf, et al. 'Linking Out-of-Body Experience and Self Processing to Mental Own-Body Imagery at the Temporoparietal Junction.' The Journal of Neuroscience, January 19, 2005, 25(3):550-557 [abstract] image: wikimedia commons.