Dear Dr. Harnad
Please find enclosed my revised manuscript, which has greatly benefited from the commentaries of the informal review. I have increased the scope and substance of the paper by inserting appropriate references to, and discussions of related work as suggested by reviewer #1, and I have inserted new paragraphs to clarify some theoretical and epistemological issues that were unclear in the original draft. I also considered your suggestion of "test piloting" in Psycholoquy. However the message of this paper is very visually oriented, and the many figures are an indispensable part of its theoretical message, which would be lost in the all-ASCII format of Psycholoquy. Furthermore, this paper is no ordinary incremental advance, but a fundamental challenge to some of the most basic assumptions underlying contemporary psychology and neuroscience. I consider it therefore eminently appropriate for BBS.
Both reviewers acknowledged that the paper is interesting, and a welcome challenge to the orthodox view. Reviewer #1 even chides me for attempting to overthrow too many widely held beliefs without arguing against those positions in detail. In fact this argues all the more strongly why this paper is appropriate for publication in BBS. For as in most challenges to existing paradigms, it is not the details that are really in question, but the fundamental assumptions underlying the competing paradigms that are in contention. In Kuhn's words, (Kuhn T. 1970 The Structure of Scientific Revolutions. Chicago University Press, p. 156)
"if a new candidate for paradigm had to be judged from the start by hard-headed people who examined only the relative problem-solving ability, the sciences would experience very few major revolutions. But paradigm debates are not really about relative problem-solving ability... Instead, the issue is which paradigm should in the future guide research on problems, many of which neither competitor can yet claim to resolve completely. A decision between alternate ways of practicing science is called for, and in the circumstances that decision must be based less on past achievement than on future promise."
I suspect that misunderstanding on this essential issue lies at the root of many of the criticisms raised by Reviewer #1. The principal message of my paper is that the subjective conscious experience cannot be ignored, for it represents a primary source of evidence for the nature of the representation in the brain. This automatically challenges ALL theories of neural representation that are in conflict with the observed properties of visual experience. I provide some examples of the KIND of theories that fit that description to indicate the scope of the implications of this paradigm, and I offer a sketch of the KIND of model that would be required to provide an account of phenomenal experience. I do not intend to argue against each of those individual theories in detail, or present a detailed alternative for each one, because it is not the details that are in contention; it is the assumption, explicit or implied, that the phenomenal aspects of the modeled phenomena are irrelevant to models that account for those phenomena. That assumption is what I propose to challenge, and it is that thesis that I can and will defend.
Paradigm debates do not come around often in science, and when they do, they require a more general handling than the debates over details that characterize "normal science" as discussed by Kuhn. I suspect it is this very generality that Reviewer #1 sees as a "weak" and "idiosyncratic" presentation. The thesis of the present paper is both clearly stated and ably supported: that the conscious experience is primary, and can be quantified in an explicit perceptual model. This is a clear and positive challenge to contemporary psychology and neuroscience, which I am prepared to defend in open forum against the widely held view that consciousness is somehow irrelevant to neurophysiology.
In summary, I should like to point out some of the novel and unique ideas presented in this paper, some of which, it seems, may not have been fully appreciated by the reviewers.
The idea of modeling perception directly is not entirely new, and has been used with success in modeling color perception. (For example the CIE chromaticity space is a pure perceptual model) But the approach has never to my knowledge been applied to the problem of three-dimensional spatial perception. This has led to endless confusion in theories of vision over exactly what visual processing is supposed to do. Modern models of perceptual processing are usually expressed in neural network or connectionist terms, which therefore precludes an explicit spatial representation as observed phenomenally. The explicit quantification of the properties of phenomenal vision as presented here offers a concrete characterization of the properties of visual consciousness, as a necessary prerequisite to developing a theory of how that consciousness is generated by the brain. We must first circumscribe the explanandum before we can attempt an explanans.
The analysis of the phenomenal properties of perspective presented here is truly novel, and makes an observation not discussed anywhere else in the literature, that phenomenal perspective is a THREE-DIMENSIONAL structure, i.e. a volumetric model with perspective foreshortening applied, and is therefore COMPLETELY DIFFERENT both from the perspective seen in photography and in the retinal image, and also completely different from the geometry of the real external world. This alone is a revolutionary observation deserving of publication, for it quantifies phenomenal perspective as never before, while providing concrete evidence of the perceived world around us as an INTERNAL rather than external entity.
The functional value of this unique form of perspective is that it offers a way to define an explicit volumetric representation of an infinite external space in a finite bounded internal representation. This too is a truly unique and novel concept introduced in this paper.
The elusive Gestalt properties of perception are here named and specified more precisely than elsewhere, as the principles of emergence, reification, multistability, and invariance. This paper also points out that perceptual structures rotate and translate coherently through perceived space, which suggests a non-anchored representation in the brain. While some of these properties have been discussed individually elsewhere, the discussion of all of them together, and the explicit description of their individual properties presented herein greatly clarifies the precise nature of Gestalt processes, and thereby highlights the inadequacy of conventional notions of neural representation.
An explicit computational solution is proposed that exhibits exactly those same elusive Gestalt principles of emergence, reification, multistability, and invariance, i.e. this is the most detailed specification to date of a Gestalt model that does not only replicate one or two selected aspects of Gestalt, but attempts to address all of them in a single model. This solution is truly unique in the literature of visual processing, and the kind of computational mechanism proposed is thoroughly different from any other computational mechanism ever proposed.
The oft-cited "problem of the homunculus", so familiar in the literature as a challenge to any "picture-in-the-head" account of visual representation, IS convincingly exposed as being invalid. (more on this below in response to reviewer #1) While this counter-argument is not new, it is certainly not widely known, because the fallaceous homunculus objection continues to be cited, and therefore this issue needs to be more widely discussed.
All of the truly novel and unique ideas in this paper follow directly from the single general principle, that the phenomenal world is a direct manifestation of patterns of electrochemical activation within the physical brain, and therefore the dimensions of conscious experience provide valid evidence for the nature of the internal representation. If it was not explicitly stated by any of the reviewers, it should be stated clearly here, that this paper represents a thoroughly novel and truly unique approach to the investigation of the visual representation, that has deep implications both for the nature of visual consciousness, and for the nature of the neurophysiological representation in the brain. The revised version of the paper now includes a new section on the epistemological implications of the theory, to highlight the paradigmatic nature of what is being proposed.
The standard peer review process is very much stacked against outsiders with a new perspective, since the committee of reviewers is almost certain to include at least one dissenting opinion, and this always seems to carry more weight with the editors in the final decision than a positive review. An earlier version of this paper was finally rejected by the journal Perception after two full years of wrangling with unimaginative reviewers, despite the fact that I had good responses to all their objections. It is for this very reason that I submit specifically to BBS where I was hoping to get the opportunity to defend the theory in open debate, rather than having it quietly rejected by anonymous reviewers. I believe I have demonstrated that this theory is both truly novel and unique, and not easily refuted with trivial arguments, and reviewer #2 seems to be in agreement. Therefore this paper deserves to be exposed to the wider community to allow them the opportunity to reach their own conclusions on the matter.
I present detailed responses to the individual critiques in the following attached pages.