Consciousness not yet explained
Ray Tallis, Academy of Medical Sciences
New Scientist, 9 January 2010
Tallis attacks the latest fad in consciousness studies, to the effect that near-term advances in technology will allow more and more accurate correlations between neural activity and conscious experience, and that when sufficient accuracy of correlation has been achieved, consciousness will have been explained. This idea that finding correlations will amount to an explanation is something that has crept up on mainstream consciousness studies. In the 1990s, it used to be clearly explained that correlation was not identity. Thunder and lightning are correlated, but thunder is not the same physical thing as lightning. However, since Crick and Koch encouraged researchers to concentrate on the correlates of consciousness, somehow the basically illogical or even magical idea that the correlates of consciousness are necessarily the same thing as consciousness has been allowed to work its way into consciousness studies.
Tallis is also dissatisfied with the approach of mainstream neuroscience and its philosophical under-labourers to the issues of the self and freewill. The mainstream denounces these notions as non-existent or illusions. The author takes the view that declaring the data that they have been called on to explain (self and conscious will) to be non-existent, does not constitute an explanation of the data.
Tallis also considers that there is a problem with time and consciousness. Memories are stored in the cortex, effectively coded into configurations of synapses. The author worries that our synapses exist only in the present, but our experience of memories allows us to experience the past. He refers here, to relativity theory, as viewing the distinction between past, present and future as an illusion. I am not sure that there is such a great problem here. Special relativity proposes that every point has its own frame of reference. If two people shared the same frame of reference, and then moved apart at differing speeds, time will progress at different rates in their now separate frames of reference, but within each individual frame of reference, the increase in entropy, which is seen as the hallmark of time, will progress at a consistent rate, and should therefore be relevant to the behaviour of an individual brain.
There seems to be some rule in consciousness writing that an author has to mention Penrose, and then quickly dismiss him as wrong, but in such a way as to indicate that they have not understood what Penrose was saying. Tallis feels that neuroscience is not making much headway in understanding the unity of consciousness, sometimes referred to as the binding problem. He conflates Penrose, McFadden and strangely Crick, as researchers who have attempted to explain this unity, rather as if they had propounded the same theory. He argues that a unification of nerve impulses would not of itself produce subjective experience, which looks to be probably true. However, this fails to discuss the Penrose-Hameroff proposal that a neuronal assembly could be a unified by a macroscopic quantum feature, the collapse of which could give access to subjectivity. Even at the more modest level of Crick’s original advocacy of the gamma synchrony, it seems reasonable to think that this could bind together different modalities, although it does not appear to do anything to explain qualia or subjective experience as such.
In the end, it turns out that Tallis is a ‘mysterian’ or ‘new mysterian’ in that he thinks that it is in principle beyond the ability of science to explain consciousness. Science is about objective measurement, which is a level which rejects the validity of subjective experience. Science is interested in measuring the frequency of photons bouncing of an object, rather than listening to my subjective impression that the object is red, but it is the latter which needs to be explained here. This seems to leave us in limbo. Tallis does not seem to be proposing a dualist ‘spirit stuff’ explanation, so there is apparently no reason at all for consciousness. This seems a rather defeatist position. My own feeling is that if we are not dualist, and the argument against dualism appears strong, consciousness must be some physical process or force, and as such can ultimately be described in terms of physics.Tags: Ray Tallis Posted by