The field of social cognitive neuroscience (sections 6.2.2.1 and 6.5) continues to thrive, with a new journal — Social, Cognitive and Affective Neuroscience — published by Oxford University Press starting 2006, and the appearance of reviews such as Amodio and Frith (2006).

In addition, the most serious and detailed attempt to explain how levels are related to one another appears in a two-volume set edited by Smolensky and Legendre (2006). The aim is to solve the grounding problem (see sections 2.5.2.4, 4.3.2, 4.3.3 and 6.4.3.3) but the solution offered does even more and has implications that go way further. Taking language as its exemplar topic, these volumes show how symbolic processing, including changes governed by ‘rules’, can be implemented in lower-level neural networks. There are mathematical and practical demonstrations of how a virtual machine emerges which handles the abstract and highly structured concepts which are the stuff of cognitive processing. The model integrates a wide diversity of ideas from fields of inquiry that include philosophy, cognition, mathematics and neuroscience. Twenty years in the writing, these books appear daunting at first; however the opening chapters provide a clear introductory explanation of the issues and of the proposed theory and are certainly worth reading in their own right. They also give a useful overall guide-map as to how the topics within the rest of the books are organized.

Section 6.2.3 Quantum level

Further arguments against the relevance of quantum theory to consciousness have been published by Koch and Hepp (2006). These include the current lack of any workable large ‘quantum computer’, the problem of simultaneous isolation of the wave states and their connection to the rest of the world for input and output, and the power of conventional neuroscientific and non-quantum physical approaches to explain our cerebral computational abilities. The engagement of consciousness with the quantum level is satirised via a variation on Schrödinger’s cat-in-a-box thought experiment (which in turn satirises the theory that the physical world only becomes fixed into a single, definite condition when its quantum state(s) interacts with an observer: see Side-box 6.1). Koch and Hepp suggest we could distinguish empirically whether ‘observation’ (and hence collapse of the quantum state) occurs purely when a physical interaction occurs or whether it actually requires full-blown ‘consciousness’ to collapse the probability wave. By making the observation procedure intermittent, for example by suppressing the observer’s view of the cat by using binocular rivalry, the state should either collapse (i) as soon as photons reflected from the cat strike the retina (especially if it is the retina of the suppressed eye, thus definitely precluding the presence of consciouness), or (ii) only when rivalry suppression lifts and the cat in the box becomes consciously visible to the person observing.¹ Until such speculations can really become testable, Koch and Hepp suggest we continue our research without worrying about quantum theories of consciousness.

Section 6.4.3.3 Dynamic systems theory

An account of mental processing in dynamical terms is contained in the forthcoming book by Spivey (2006), which emphasizes the continuous and distributed flow of activity that underlies all cognitive/neural processes.

References

Amodio, D.M. and Frith, C.D. (2006) Meeting of minds: the medial frontal cortex and social cognition. Nature Reviews Neuroscience 7, 268-277.

Koch, C. and Hepp. K. (2006) Quantum mechanics in the brain. Nature 440, 611-612.

Smolensky, P. and Legendre, G. (2006) eds. The Harmonic Mind, vols. 1 and 2. MIT Press, Cambridge, MA.

Spivey, M.J. (2006) The Continuity of Mind. Oxford University Press, New York.

Footnotes

1. Personally, I have always wondered what would happen if the state of the cat in the box was monitored at a point in time by a physical system such as a digital camera, the image encrypted and then transmitted to a storage device such as a computer disk, and then the unopened box with the cat in it placed on a rocket and fired into the sun (or subjected to some other process that would destroy its quantum state — a nuclear bomb or a particle accelerator, perhaps, would do the trick). A few hundred years later the image is read off the disk, decoded, printed and looked at for the first time by a conscious human. Are we to believe the quantum state of the long-destroyed cat is somehow retrospectively resolved or created by such a delayed occurrence of consciousness?