Mainstream 7

Degeneracy: He also stresses the importance of so-called degeneracy in the brain. This means that there are structurally different elements of the system that are able to produce the same output. In particular, this gets rid of bugbears such as the so-called grandmother cell. This was the idea that there could be a neuron with a particular function, such as recognising one’s grandmother. In Edelman’s scheme there is degeneracy, which allows different cells, or more likely groups of them, to deal with recognising grandmother at different times.

Categorisation: Perceptual categorisation is viewed as being one of the most important functions of brains. This allows the signals from the environment to be split into sequences that are useful for behaviour. So the signals from a room can be split into categories such as ‘chair’ and ‘table’. This involves a so-called global mapping, where maps of different sensory modalities are linked by reciprocal connections. A further step is to generalise between perceptions in order to create concepts. Finally, Edelman’s theory of brain function requires memory. Changes in synaptic function favour the use of neuronal circuits that re-enact particular events. Again there is degeneracy, so more than one set of neurons can re-enact particular memories. Moreover, it is a re-enactment in the sense that it may be somewhat different from the original event. Recall is seen as being influenced by the value system neurotransmitters, thalamocortical mapping and sub cortical structures such as the hippocampus and basal ganglia.

The binding problem: Edelman sees the development of these systems as a necessary precursor of consciousness. The emergence of re-entrant or reciprocal systems is identified with the evolution from reptiles on the one hand, to birds and mammals on the other. In particular, this was the stage at which the reticular nucleus started to select the activity of the nuclei in the thalamus. Edelman stresses that the thalamocortical system interacts mainly within itself, and has relatively few connections with the rest of the brain. He relates this to the distinction between conscious and non-conscious systems in the brain. It is also proposed that the reciprocal action between the neuronal circuits within this part of the brain is what allows perception to be bound together into a single coherent whole, thus solving the binding problem. Edelman further considers that the sense of self originates from the bodily sensations of the infant, to which the experience of other qualia are added as the individual matures. The thalamocortical activity is suggested to be stable over periods of between a few hundred milliseconds and a few seconds and this is identified with the ‘specious present’ originally suggested by William James. This is sometimes referred to as the ‘remembered present’. Edelman also reworks the Dennett approach to zombies, which is also at heart a sleight of hand, in a new form. The philosophical concept of a zombie is that it would be possible to have an entity that performed all the functions of a human without consciousness. Dennett’s (and Edelman’s argument) is that if the zombie is exactly the same as the human it must have consciousness, because that is part of being human. This is obviously true, but in true consciousness studies fashion, it evades the real matter of the zombie argument, which is that the known activities of humans could be performed non-consciously. Edelman has decided that consciousness must arise in the reciprocal setups of the thalamocortical system. These processes are seen as being centred round a self that is a reference point for memory. Edelman refers to the thalamocortical area as the re-entrant dynamic core, and this is where he looks for consciousness. At this point, his account makes a jump or massive assumption that leaves an explanatory gap behind it. He suggests that the dynamic core converts signals from the external world and the brain itself into what he refers to as a ‘phenomenal transform’, which are in fact qualia or consciousness. There is nothing implausible about relating consciousness to this area of the brain, but what is lacking is any explanation of how the signals are suddenly converted into consciousness. In fact, the very use of the phenomenal transform term looks like a bit of a fudge. We are still wondering what this higher order sounding term means, when we discover it means consciousness. If it was simply stated that the signals were turned into consciousness, we might be more inclined to ask how it was done. The whole arrangement is a bit like the cartoon of a consciousness lecture, in which a string of equations is followed by ‘and now a miracle happens’ and then more equations.

More puzzles follow. It is fair enough to say that qualia refer to distinctions, say for instance the distinction between green and red, and that in the brain this is based on neural activity. What is not explained is why we experience this as conscious qualia. A non-conscious machine can just as easily make the distinction between a red and green light, without any need for the additional effort of generating qualia. P. Things get curioser and curioser. It is stated that the ‘phenomenal transform’ is not caused by neural activity but is nevertheless a ‘simultaneous property’. This gives no explanation of how this property arises. If it doesn’t arise from the activity of neurons, what does it arise from? It looks as if consciousness as been simply declared to arise at this point, because this would indeed fit in nicely with the earlier and more convincing discussions of brain function. Edelman doesn’t feel the need to investigate the origin of the ‘phenomenal transform’ any further, and instead moves on to discuss whether it could be causal. For this exercise the phenomenal transform is referred to as C, and the underlying neural processes from which it has mysteriously arisen as C’. It is stressed that C cannot arise in the absence of C’. C is now without previous warning stated to be a relationship, having previously been a property, albeit only a ‘simultaneous property’. It is not stated what it is a relationship between. Perhaps, we are supposed to intuit that it is a relationship with C’ neural activities, except that earlier on it was granted the dignity of being a property alongside the neural activities. At any rate, being a relationship disqualifies it from being causal, according to the laws of physics, which might have been thought to have been rather brutally ignored in the preceding discussion.

Something has happened here that has been seen before in mainstream consciousness studies. While the concept of non-physical is denied, it seems possible, when it’s convenient, to classify consciousness as non-physical, in order to prevent if from being causal, and thus opening up the whole question of freewill. Here consciousness or the ‘phenomenal transform’ was initially described as a property, albeit a simultaneous property, and in the scientific understanding of the universe properties come with a physical description. Later the phenomenal transform, under the guise of C, is demoted from a property to a relationship. However, even this doesn’t justify the non-physical therefore non-causal tag. Relationships are instantiated in matter or energy. The gravitational force between the Earth and a falling rock might be described as a relationship, but for an organism positioned directly beneath the rock, it would be adaptive to regard the relationship as causal.