Ms. CCOG2000-0061

This paper presents an analysis of three theories of perception that are normally discussed by philosophers direct realism (which most contemporary philosophers accept), representative realism (which most neuroscientists vaguely believe in and most philosophers vehemently reject) and a minor player the projection theory. The author decides that all of these are unbelievable but nevertheless decides that representative realism must be correct. The author also supports the validity of a phenomenological approach, as currently used by what he calls "perceptual scientists' (AKA introspectionist psychologists such as M.D. Vernon, Gregory, Ramachandran, Smythies and earlier the Gestalt school) for finding out what consciousness really is. Mixed into this are discussions (i) whether the brain uses digital or analogical systems for neurocomputation and (ii) whether the Identity Theory of mind-brain relations is correct. This mixture evidences signs of conceptual confusion, also known as paradigm mistakes, as follows:

1. Lehar is quite correct when he rejects nave realism and accepts the representative theory . However, his evidence is based almost entirely on the work of Revonsuo and Clark and by pointing out the very obvious defects in Dennett's ideas. He makes no mention of the vast amount of data accumulated by the scientists listed above and by many others that shows that we do not perceive what is actually out there but only what the brain computes as being most probably out there (see e.g. Smythies & Ramachandran (1998) An empirical refutation of the Direct Realist theory of perception. Inquiry, 40, 437-438). I recommend that some brief statement of this data, including Vernon's book "A Further Study of Visual Perception", should be included.

2. His account is based mainly on vision and he only mentions somatic sensation briefly e.g. at the foot of page 13 he says that the brain fabricates "a copy of my own body at the center of that environment." This, of course, is what is called in neurology the "body image". I suggest that Lehar includes a wider discussion of this concept as contained in Paul Schilder's classics "The Image and Appearance of the Human Body" and "Mind. Perception and Thought in their Constructive Aspects" as well as Ramachandran's "Phantoms in the Brain", and Smythies J. (1953) The experience and description of the human body. Brain, 76; 132-148. An appreciation of the fact that we experience the body-image in consciousness and not the physical body eliminates what Lord Brain called the "externality problem" to which Lehar devotes considerable attention.

3. Lehar states (p. 5) that "The indirect realist view is also incredible, for it suggests the solid stable structure of the world we perceive to surround us is merely a pattern of energy in the physical brain." And again (p. 9) "we are compelled to accept the reality of conscious experience as a direct manifestation of neurophysiological processes within our physical brain." i.e. he is claiming that the Identity Theory is confirmed as true by this argument. However, this is not so. The establishment of representative realism as true in no way supports the truth or falsity of the Identity Theory which is a logically entirely independent problem. Lehar further states that the establishment of the truth by physiological methods of the Identity Theory validates the phenomenological approach to the study of conscious experience. Again there is absolutely no connection between the two concepts. Introspectionist psychology produces results on its own and does not need such metaphysical underpinning.

4. These problems arise because Lehar does not give an exhaustive account of the scientific theories of mind-brain relationship currently extant. He assumes that there is only one, the Identity Theory. Anything else he darkly alludes to as "mysticism". However, there are two rival scientific theories (see Smythies J. The Walls of Plato's Cave and Smythies J. Requiem for the Identity Theory. Inquiry, 37, 311-329 and Smythies J. Consciousness: some basic issues, a neurophysiological perspective. Consciousness & Cognition 8, 164-172). The first is the Heisenberg/Bohr theory of mind-brain complementarity and the second is the Theory of Extension developed by the philosophers Bertrand Russell, C.D. Broad, and H.H. Price, by the physicists Andrei Linde and Bernard Carr and by the neuroscientist John Smythies amongst others. Both these theories avoid the tortuous attempts that people make (including Lehar) to try and show that brain events and phenomenal events are really identical when it is perfectly obvious that they are as unalike as they could be. Leibnitz's law states that if A and B are identical then they must have identical properties, which nerve nets and sensations singularly fail to exhibit. I suggest that Lehar should include a mention of these rival theories. In the theory of extension consciousness is postulated to exist, as a material and organized entity, in a space of its own outside what is currently regarded as the physical universe. The relationship between the sensory fields of consciousness and their correlates in the brain is causal and not one of identity. The visual field really is the screen of a televisual apparatus and the brain is analogous to the machinery inside the set. This theory is perfectly compatible with the contemporary physics of Kaluza-Klein, superstring and brane-bulk theories.

5. On pages 10-11 he correctly dismisses the "Homunculus" argument as invalid but fails to distinguish between epistemic and non-epistemic perception at the heart of this matter (see more on this below).

6. On pages 13-14 he claims that the representative theory allows us to say that the brain uses an analogical strategy for neurocomputation and that this results in the brain constructing the full 3-D spatial effigies of external objects that we experience. This argument is implausible. The relevant technology for constructing full 3-D spatial effigies is hands-on television not computer science. Thus the physiological meaning of 'analogical' becomes obscure (see pages 22-23). In any case neuroscientists recognise that the brain uses other strategies besides Boolean logic, for example parallel processing and Freemanian chaos. Neither of these however could construct the televisual virtual images in what Crick called "glorious techicolor' that we actually experience.

7. The zombie argument on n pages 14-17 is not plausible either. A zombie may have all the brain machinery needed to "walk about in the world avoiding obstacles like we do" (as a very sophisticated robot could too) without generating a conscious visual field. Suggest leaving out this argument.

8. On page 15 he shows that he fails to distinguish between epistemic and non-epistemic perception. He says "for qualia are the carriers of the information experienced in perception". Well not always. In associative agnosia a patient can see objects perfectly well but does not know what they are. In other words he/she fails to gather information from the qualia (better sensations). In blindsight the opposite is the case. Here the subject cannot see the object but can gather correct visual information about it. What this implies is that in these cases the brain mechanisms mediating the last stages of conscious seeing are different from the brain mechanisms mediating the extraction of information from the visual inflow.

9. Page 16-22. The Plotting Room analogy is ingenious but could be shortened.

10. Page 25. "we posses an internal map of external space" .Yes we do and there is much data to indicate that this is located in the hippocampus. But this in no way resembles the (tele)-visual field of experience.

11. The lack of clarity about what analogue strategies are clouds the section on motor performance.

Conclusion. This paper is certainly heading in the right direction but needs considerable reworking.