Rethinking the Process of Vision

The following text is abstracted from Wikipedia:

“Scotopic vision is the monochromatic vision of the eye in dim light. Since cone cells are nonfunctional in low light, scotopic vision is produced exclusively through rod cells. Vision in normal light with functioning rod cells is photopic vision”.

That “cone cells are non-functional (or shutdown?)…” there is just no experimental evidence for such a statement! One would reason this way if one believed that cone cells are the source of color…which they, clearly in this explanation, are not! “Scotopic vision is produced exclusively through rod cells”… how on earth? …invoking what mechanism? Scotopic and photopic vision are therefore presented as two separate systems. What physical evidence is there for this statement? From the viewpoint of my geometric explanation all of this is completely erroneous and leads one down the wrong path of thought… and has done so for years and years, i.e., the fallacy that “cones detect color and rods black and white”! It attempts to explain phenomenologically the behavior of the vision process but, in fact, uses the completely wrong mechanisms.

There is really only one system, but, if one must use these terms these are the proper definitions:

Scotopic vision: “Under low light level conditions the rod receptors of the peripheral retina are linked together (as experiments show) to act as a “wide angle light meter” with the exact short wavelength limit of visual response (~400 nm) controlling pupillary constriction, dilating the pupil of the eye and admitting the maximum amount of light to the retina. Under these conditions light intensities of the three primary RGB wavelengths falling on the the retina are insufficient to activate the “Land color mechanism”, i.e., there is insufficient intensity incident on either side of the geometrically determined mid-band (550 nm) reference point at 7-8 degrees of retinal eccentricity to allow a ratio to be obtained and the hues of color perceived. The historic misconception that “rods detect black and white” is explained.

Photopic vision: “Under normal daylight levels of illumination the three primary RGB light intensities abstracted by the retina are sufficient to activate the “Land color mechanism” as defined above and the image including the hues of color is perceived. The peripheral rods, as above, constrict the pupil  controlling the intensity of light entering the eye to levels that will not damage the retina”.

There is only one “system”!

GCH

4/25/08

I was reminded of Edwin Land after seeing his picture in the Business Section of yesterday’s New York Times. When I began this work on vision in 1991 one of the first things I remembered were Land’s anomalous color vision experiments of the 1950’s that derived a full color image from the superposition of two black and white negatives. This strange result even rose to the pinnacle of popular science at the time ascending to the cover of Scientific American (May 1959). Edmund Scientific (for those who will remember!) even sold kits of these negatives so that one could perform this feat at home. I felt certain that in the forty intervening years vision science would have provided an explanation. It became clear, however, that not only had the experiments not been explained but Land’s name had almost completely disappeared from the literature of vision!

In one exchange with a prestigious university group engaged in vision research I was told early on that “the field had put Land’s work to bed years ago” and I was pointed to a paper by Walls with the curious title that shouted “LAND! LAND!”. This paper had been published in Physiological Bulletin (Vol. 57, No. 1, 1960). Incidentally, this reference does not seem to appear associated with Walls’ publications on the web. I dutifully obtained the paper and was distressed to find that it consisted of page after page of ad hominem attacks on Land and his experiments damning him with faint praise as an “inventive genius” (read “not a scientist”). Land’s experiments generated a great deal of excitement at the time with Walls quoting, generally without attribution, the numerous (and admittedly exaggerated) popular claims made about the work (statements made such as “scientists since Newton have been completely fooled about the way that the eye sees color”). After setting the stage with an entire column of these claims, Walls finally notes that Land has disavowed them! The remainder of the fourteen pages of the paper is replete with quotation marks essentially mocking Land’s work. In my view, even after this lengthy rant, he never provides an explanation for the experiments! In summary, this paper is certainly not objective science. So much for that!

I will not here attempt a complete characterization of Land’s work on color vision. Suffice it to say that his conclusions, drawn from measurements made external to the eye are, I believe, now explained by the geometric/optical antenna finding of my work. The parallels are dramatic – his observation that a wavelength dividing “fulcrum” must be present somewhere in the vision system is seen to correspond to the geometrically defined mid-band point at 7-8 degrees of retinal eccentricity that I geometrically define. Importantly, this fixed reference also explains for the first time the “color constancy” of vision. Land demonstrated, again from measurements made external to the eye, that the many hues of color are obtained by the eye calculating a ratio of light intensities (Land termed them “lightnesses”) on either side of this mid-band fulcrum point. This is the first place where the term color should be introduced in the vision process! Although Land deduced this without knowing the light interaction mechanism internal to the eye, my geometric explanation shows that the retina is sensitive to light intensities (his “lightnesses”) in three fixed- wavelength (RGB) bands and that these correspond to what have historically been termed the “primary colors”. One sees now, however, that these three wavelengths should not be termed “colors” at all reserving that term for the above defined ratio of light intensities on the retina.

In his work Land had available only the traditional model for light interaction in the eye. He proceeded, in the only way open to him, to develop an algorithmic theory – that he termed the “RETINEX” - to simulate the results of his color vision measurements. This work is a relatively difficult to follow and perhaps not necessary with this new corroborative understanding of the retina and the eye.

I have suggested that anyone interested in Land’s work should request the complete compendium of his papers from the Rowland Institute in Cambridge, MA that Land founded (that has now been subsumed into Harvard). These papers were sent to me in the early 1990’s by Holly Perry then in residence and who had been an associate of Land. She may have retired by by now but she was very helpful to me at the time. A review of these papers reveals the lucidity and true method of scientific inquiry characteristic of Land’s work. One must see the true character of scientific pursuit in this work! I have seen this only once before and that was in the writings of the physicist David Bohm!

One might also read Victor McElheny’s book “INSISTING ON THE IMPOSSIBLE - THE LIFE OF EDWIN LAND” (Perseus Books). Chapter 14 of the book describes in some popular detail Land’s color vision experiments. A quote (p.258) attributed to Land is particularly interesting here:

“Land spoke of the eye’s using light reflected from the scene to form at least two ‘identical but separate records of the scene’ one with longer wavelengths and the other with shorter” .

This is exactly where my explanation of light interaction with the retina leads. The dividing point between the two regions is the geometrically-determined wavelength reference at 7-8 degrees of retinal eccentricity (the exact center of midband G intensity that explains color constancy!) with Land’s long and short color vision records determined by ratioing intensities on either side.

It is my belief that Edwin Land was the true scientific genius of the field of color vision. His work should, and certainly will ultimately, be recognized!

Respectfully,

Gerald C. Huth, Ph.D.
Ojai, CA

Beginning with my interest in the concept that light interacts with spatial antenna dimensionalities proposed in a U.S. patent (Marks) it became clear that, when applied to the retina of the eye, this type of spatial interaction explained a great deal that had been heretofore left unexplained in the vision process. Examples include providing a basis for understanding the anomalous color vision experiments and reasoning of Edwin Land, an explanation for the longstanding conundrum of color constancy in vision, the primal cause of the medical condition termed macular degeneration, and the processes involved in color variant vision (color blindness). Parenthetically, it also became clear that the retina of the eye evolved as the direct biological embodiment of the principles of the diffraction of light – nothing more! All of this is discussed in Huth. Specifically, it is seen that light interacts as the wave of classical physics in the space between receptors and not in the body of the receptors themselves that has for so long assumed. In the retinal structure these light wave-accepting spaces are immediately adjacent to quantum confined electron (EQC) spaces (formed by the receptors themselves) that constitute the absorbing mass. It is then seen that the rhodopsin protein within receptors has a structural function in conducting light energy to the signal-producing isomerization of the retinal molecule. Using this construction it immediately becomes clear that the plan of the retina actually forms a geometrically-defined 2-D Fourier transforming surface whose properties follow directly (calculated) from the historically measured, and oft quoted, asymmetric morphology of retinal receptors (“Cone-Rod Distribution in Human Retina”, G. Osterberg, Acta Opthalmologica, 1935).To my knowledge this is the first time that Osterberg’s data has been explained rationally. Harris in a recent proposal has also concluded that the retina is a Fourier surface.

The human eye possesses the remarkable and well documented ability to discern the interaction of single photons (Rose) but the mechanism involved in this biological structure has never been forthcoming. I propose that this gives, or should have given, credence to the idea that quantum theory is somehow involved in the vision process. We really must give thought to this! My work may provide an answer in positing that the vision process actually operates in at least two distinctly separate time domains. The first: TIME DOMAIN A is located at the outer segments of retinal receptors where the initial light interaction occurs. This interaction is in very fast time indeed it having been shown (Hamm ) the first step in vision - the cis-trans isomerization of the retinal molecule - occurs in femtoseconds (10^-15 sec). In the subsequent TIME DOMAIN B, signal processing involves slower ionic mechanisms characteristic of the biological sub-retinal “circuitry” and in transit through the optic nerve. This time domain has the function of “slowing down” the visual image information to human nervous system proportions. Times here approximate milliseconds (10^-3 sec). Consideration of time and space involved in A. defines this as a “quantum domain” interaction. Might it be therefore that it is light interaction with the outer segments of retinal receptors that represents the interface between quantum reality (whatever that turns out to mean!) and the human system. The slower, millisecond, reaction of B has long been misunderstood as the “reaction time of the eye”.

The retinal outer segment light detection centers (“devices”) that I have defined , comprising sub-micron interreceptor spaces and EQC centers, conceptually possess electronic properties (capacitance, etc.) consistent with signal response in this time domain. Electronic noise is a time integrated function. Viewing light interaction (signal generation) in times as short as femtoseconds brings in the role of time (Tove and Huth) in reducing electronic noise. This effect may explain the extraordinary sensitivity of the visual process.

I have proposed that the retinal outer segment devices possess the ability to detect light intensity and phase as required by the Fourier equation. This follows from the initial geometric explanation of the plan of the retina as a diffractive Fourier surface based on an “antenna” model. Such a surface encoding light intensity and phase behaves as (or is the definition of) the phase conjugate “mirror” (Phase Conjugation) so well known in the laser field. Such a mirror surface reflects each light ray back upon the exact path on which it entered, in this case, the eye, and in the process eliminates the effect of scattering. The retina acting as such a surface, as I believe, would explain the longstanding conundrum as to why the outer segments seem to “point the wrong way” ( for example, a recent paper (Svet) discusses the problem of image distortion by light scattering in passing through the sturucture of the inner segments of retinal receptors). These thoughts lead, in turn, to perhaps the idea that the eye, instead of being the passive receiver that has for so long been assumed, may actually re-radiate a signal that corresponds to the visual image back into the external environment/world along the phase conjugate path, It is well understood that antennas in addition to detecting electromagnetic radiation can equally well transmit such radiation. Might the eye actually transmit? And, if this were so, might this provide an “interconnectedness” with the external environment relevant to the subject of consciousness? I have made the point above that the plane of retinal outer segments where initial light interaction occurs can by definition be said to operate in the space and time realm of quantum physics. Might this plane be the “Heisenberg Cut” –the point an observed system from an observing apparatus in the Copenhagen interpretation of quantum theory – the point .that divides the probability wave nature of quantum reality with the classical reality of macroscopic “things” that we see and feel everyday. I’ll not go further into this deep (!) subject but will add the following quotes that seem to show that others have thought along these lines:

“Von Neumann tackled these problems by considering an idealized situation
in which there is a sequence of measuring devices, each probing the output
of the device that precedes it in the sequence, and by then following the
causal chain first into the retina of the observer, and then into the optic
nerves, and then ever deeper into the brain until at last the entire brain of the
observer is treated quantum mechanically, along with the rest of the physical
universe”.(italics mine / GCH)

“Quantum mechanics rationally accommodates, therefore, a two-way causal linkage between mind and brain, whereas the concepts of classical mechanics provide no rational foundation for a causal connection in either direction. Quantum mechanics leads, consequently, to a radical revision of the conception of man. Whereas classical physics reduces man to a machine, quantum mechanics allows man to be an injector of physical counterparts of mental concepts into the structure of the physically described world. Physical counterparts of mental concepts can be identified and honed into brains by trial and error learning”.
(Henry P. Stapp, “MIND, MATTER AND QUANTUM MECHANICS”, Second Edition)

Submitted:

Gerald C. Huth, Ph.D.,
Ojai,CA
4/9/08