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Self-only consciousnessSelf-only consciousnessThe Importance of what's missing Terrence Deacon, University of California Berkeley New Scientist, 26 November 2011 Keywords: Consciousness, the self, sensory cortex, frontal cortex The author acknowledges at the beginning of this article that despite two decades of intensive work in both neuroscience and consciousness studies, we do not appear to be any nearer to forming a scientific consensus on the nature of consciousness. He starts by discussing the constraints that emerge in physical forms. For example, as a snow crystal grows the positions for new additions to the crystal become more and more restricted. What is not present or not able to be present is seen as being as important as what is present. The author intends to relate this type of abstract rule to consciousness. This leads him to discuss molecular processes in relation to the constitution of 'the self'. These molecular processes tend to self-assemble and to reconstitute in the event of disruption, and thus become a self-sustaining process with an 'end' of maintaining themselves. This is suggested to bring with it a capacity for distinguishing self and non-self. This approach to the self may be interesting, but what is disappointing from the point of view of deriving a theory of consciousness is that it is effectively a resort to the oldest 'get out of jail free' card in consciousness studies. The author assumes without seeming to be aware of any need for even arguing the case that 'the self' is the same thing as consciousness. Now all that he needs to do is to explain or deconstruct the self, which has been done by many writers with less complex systems than the molecular basis suggested here. Self-only consciousness The initial argument against 'self-only' consciousness is that we are conscious of a lot of things other than the self. However, this introspective approach is now supported by recent studies. Rafael Malach of the Weizmann Institute carried out a study, in which he scanned the brains of subjects watching a film containing dramatic or emotional content. It was shown that the more engaging the film, the less activity there was in the frontal cortex, which is associated with the formation of the self. There was a similar finding in a study by Hasson et al (2004), which also scanned brain activation in subjects viewing a film. In general, the rear part of the brain, which is orientated towards the external environment, demonstrated widespread activation. In contrast, the front of the brain and some areas of the rear brain showed little activation. These less active areas are referred to as the 'intrinsic system' that deals with introspection, and the 'first person' or 'self' aspects of the mind. This network shows a major reduction in activation at the times that perception is most absorbing for the subject. In Malach's study, the gamma synchrony, which is the best known correlate of consciousness, was seen to have widespread activity in the sensory cortex and the limbic areas rather than the frontal regions associated with planning and execution. Malach suggests that the role of the frontal areas is not to create perceptual consciousness, but to deliberate on the significance of the sensory experience. He thinks that when subjects are sufficiently absorbed by their sensory perceptions, as with the film used in his study, they 'lose themselves', in the sense of not having any introspection about what they are perceiving. It is also argued here that consciousness arises of its own accord in the sensory cortex, without being dependent on the frontal cortices supposed to be related to the sense of self. This argument looks to undermine attempts to dismiss the problem of consciousness by conflating it with the self, and then after that deconstructing the self. |
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