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Out Of Our HeadsOut of our Heads Alva Noë Noë's thesis revolves round his interpretation of two experiments with neural plasticity. A study performed on ferrets showed that if their eyes were connected to their auditory rather than their visual cortex, the animals were able to see, while using what would normally be the neurons related to their auditory experience. Another interesting study involved a long running attempt to give sight to blind patients. This actually had some technical success although the results were not considered practical. The device involved connecting a camera to a series of vibrators attached to the body of the patient. Visual information entering the camera produced vibratory effects on the skin that were transmitted to the somatosensory cortex. But at this level, on the basis of signals in what would normally be the area of the brain producing tactile experience, the patient was able to judge the size, shape and number of objects in a room, and to reach and pick up objects. Noë might have added that synaesthesia suggests much the same thing. In one of the most common forms of this, abnormal projections from the auditory cortex into the visual cortex allow synaesthetes to attribute colour to numerals or letters. Interesting enough, but the real query is over the type of interpretation that Noë places on these studies. His suggestion is that because areas of the brain can be persuaded to process a different modality from their normal one, say sight instead of touch or hearing, then it is not really the brain that produces the experience. It is hard to see why this should be the case. Noë makes much of the fact that the different sensory cortices do not by-and-large have different neurons. This is supposed to indicate that the different modalities cannot arise in the brain. This seems a very sweeping judgement. All that would seem to be justified is a statement that different modalities are not a function of the types of neurons involved. The evidence of these studies would rather seem to suggest that neurons can decode and differentiate between the varying types of electrical nerve impulses produced by visual, auditory and tactile data. An alternative explanation might be more convincing if there was any real attempt to explain a physical process by which the 'something it is like' of conscious could be generated by the environment outside the brain, but this is not apparent in this book. Many would agree that the realisation of the importance of feedback from the body and the movement etc. of the body in the environment is an advance on the slavish 'brain's a computer' model of the last century. However, in the end there's no evidence that the environment or the body have any special mechanism for producing the 'something that it's like'. It is true that we can't agree this for the brain either, but recent work has at least produced correlates in the brain, for which there is nothing analogous outside the brain. These correlates are the global gamma synchrony and the jump from baseline to 50 Hz in some single neurons. Although the author is critical of mainstream neuroscience and by extension consciousness studies, he appears to remain committed to some of the last century's restrictions on thinking. At no point is emotional brain activity, now shown to be decisive in decision taking and behaviour mentioned, although some brain regions are seen to be crucial in emotional evaluation. Similarly there is a simplistic attitude to neurons, traditionally viewed as no more than electrical switches in consciousness studies. Recent decades have shown the neuron to immensely complicated raising the possibility that they have more potential for information processing than has been allowed for. However, this study does not even discuss the possibility that they might be capable of distinguishing between different types of signal. Likewise, Noë is not the first to comment on the impressive abilities of single-cell organisms, but he seems to assume that this derives from the environment without discussing the possibility that these organism may have internal processing abilities. This type of approach to consciousness is fashionable at the moment and the question arises as to why this is. My guess is that this is a function of a gradual realisation that 'the brain's a computer' model does not answer all the questions even for strict classical physics reductionists, and the body and environment approaches provide an escape route from confronting more difficult questions. |
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