I was asked if I know of Karl Pribram’s proposal that consciousness is dependent on holographic structure and is therefore, in some sense, related to the vision process. I have certainly been aware of these ideas for years but felt that they were incomplete in not providing any proposal for a possible mechanism as to how this might actually be effected. I believe that this is the reason why Pribram’s ideas although receiving a great deal of notoriety have languished.
It occurs to me that this situation is similar Edwin Land’s work on color vision where he identified the fundamental nature of this process but, with the paradigm for light interaction available to him in 1955 could go no further in explaining the mechanism involved. I would believe that Pribram’s prescient ideas about holography are in the same vein.
I believe that I provide a mechanism for a holographic content to the vision process in my explanation for light interaction with the retina. This lies in the, to me unassailable, geometric proof that the retina forms the Fourier plane of the optics of the eye….and….. the Fourier equation requires that both light intensity and phase be encoded…and these are the necessary elements for any holographic interpretation of vision.
I had not really thought about a holographic interpretation of vision until chancing upon a reference to the original paper of Gabor first describing the principle of holography. The quote from this reference that caught my attention:
“Gabor also considered only the case where the illuminating wave also serves as a reference wave”.
Axial holography! I had believed from at least a cursory overview of the holographic process and that generation of a hologram required a separate “reference beam”.What struck me in the Gabor paper was that in his initial experimentation he used a portion of the incident beam itselfto act as a wave reference in a holographic construction. I have discussed this in a previous Comment that the reader might review.
Might a holographic interpretation of vision be developed using my light interaction explanation? The necessary elements seem to be there.
The first and fundamental interaction of visible light resulting in the formation of an image in the vision process occurs at the plane of the outer segments of retinal receptors. This interaction occurs spatially in light detection centers (“pixels”) that are of dimensions smaller than light wavelength in the nanometer region and in a time frame of femtoseconds (10-15 seconds). Considering these dimensions of space and time it might appear that the role of vision is to “interrogate the quantum regime”.
I propose therefore that the plane of receptor outer segments is the point where a “quantum reality” with all of the aspects of probability etc. come into consideration.
I further propose that all subsequent biological and neural processes in the retina and the transit of the image information to the visual centers of the brain function to “slow down” the time scale of image information to human nervous system proportions. This is the regime of slower, classical physics. In theory, the existence and placement of such a transition point between quantum and classical physics has long been debated and has even given a name - the “Heisenberg Cut”.
The fundamental light interaction on the retina then occurs in “nanospace”, i.e., in sub-micron quantum confined electron spaces, and, concurrently in the extremely fast femtosecond or less time regime. This interaction then approaches a minimum of spacetime. Might one see in this a “spacetime fulcrum” that somewhat approaches Julian Barbour’s projection of a zero time – or complete absence of time?
I have been off on other things but this idea needs mentioning. I earnestly solicit the thinking of others in developing the following thoughts.
My view of light interaction with the retina seems in coincidence with a holographic explanation of the vision process.
Quoting from Cathey (Optical Information Processing and Holography, Wiley Interscience):
“ the hologram has the properties of a lens except that the wave is intercepted and stored before being allowed to continue its propagation to form an image.”
It is well understood that holographic information is stored as both intensity and phase defined by the Fourier equation. This exactly represents my description of light interaction with the retina of the eye. The intensity and phase of light are detected (and processed) at each inter-receptor (“antenna”) light interaction element of the retina.
What caught my attention from Cathey (p.58) was the statement:
“Gabor also considered only the case where the illuminating wave also serves as a reference wave”.
This quote is from Gabor’sfirst publication describing holography in a Letter to Nature in 1948 http://www.nature.com/physics/looking-back/gabor/gabor.pdf . I would note the utter simplicity of the paper. Who would have prediced the massive technology that has emerged from this simple exposition!
It had always been my understanding (never having thought in depth about it!) that a second “reference wave” was necessary to “read” a hologram.
Again from Cathey (p.58):
“Holograms can be recorded without the reference wave being introduced at an angle to the wave from the object. This, in fact, was the manner in which Gabor (see reference) made the first hologram. In making this hologram, a transparent object was used (a transparency with dark lettering) allowing the non-diffracted portion of the wave to serve as a reference wave for the information-bearing portion diffracted by the lettering.”
What startled me was that Gabor used a portion of the axially incident beam as a reference wavelength to read a hologram (the first hologram!). See his Figure 1 that illustrates this. He did not use an external wavelength reference beam.
There are many factors that enter here including coherence of wavelengths etc. but might not the eye use this principle?
I have stopped in my explanation at the point where light interacts with retinal outer segments and I have described how individual retinal inter-receptor “devices” are capable of detecting both the intensity and phase of incident light noting that this means that the retina forms the Fourier and not the intensity-only sensitive image plane of the optics of the eye,
I have not gone into how the visual image is subsequently processed other than noting that detection of the phase of incident light implies knowledge about direction and that this must ultimately be involved in formation of the visual image.
I have also assigned a role to the peripheral retina of acting as a large area “light meter” that functions to control pupillary constriction and overall light level into the eye.
Perhaps, however, the peripheral retina might reflect (antennas radiate as well as detect) a “reference” wavelength back into the beam ofimage-forming RGB wavelengths that interact at relatively narrow angles from the fovea to about 20 degrees.??? Such an interaction would occur in the time domain of light interaction or about 10-15 seconds.
The question will be asked: does the eye possess the capability necessary to process the vast information content of a hologram.
Following from my explanation – it does.
I have written that the vision field has been in error in seeing the “reaction time of the eye” as being in the millisecond (10-3 sec) time domain. Even my friend Albert Rose reported this error. This is the reaction time of the human nervous systemsubsequent to retinal interactionand not the time domain of light interaction with the retina that has been experimentally determined to be in the femtosecond (10-15 sec) region.
There is most certainly sufficient bandwidth in this fast time region to entertain the idea that the vastly increased information content flowing from the eye exists necessary to entertain the idea of a holographic concept.
Further I would add that these thoughts should provide insight into the realm of neuroscience. That field seems to accept the slow time / low information content that has traditionally been assumed.
Obviously, these are very preliminary thoughts. I welcome the ideas of others.
I propose that the outer segment of retinal receptors is the point where a quantum reality, whatever that turns out to mean, transitions from the physics of the quantum to the regime of slower, classical physics.In theory, the existence and placement of such a point has long been debated and has been accorded the term in physics “Heisenberg Cut”. The quantum spatial and temporal domains are determinative in the external world of light beyond retinal outer segments. Interior to the eye, and beyond, human nervous system requirements have evolved around the slower processes of classical physics and it is this regime that serves to convey the information of external quantum reality to the brain and the senses.
In this context, and to go forward, it is crucial to first note the well documented finding that vision possesses the ability to detect and render discernible the interaction of single photons (or, in the spirit of this work, “singlequantized interactions”). This has been known for years but I find in the literature no comments about the sheer wonder of this! Our advanced photonics technology of today cannot come close to accomplishing this feat. In the words of Charles Dickens “This must be distinctly understood, or nothing wonderful can come of the story I am going to relate”!
This single finding has always meant that quantum physics is inherently involved and must be considered in the ultimate understanding of the process of vision. Realization of this has been obscured in the literature of vision by thought echoed over the years that all vision processes occur in times consistent with human nervous system measurements such as the slow ionic (i.e., chemical ) transport of information. This culminates in such erroneous conclusions as the statement that the “the reaction of the eye is in milliseconds” when what is actually being measured is the reaction time of the human nervous system.
No satisfactory explanation has ever been put forward in the literature of vision for this unique ability of vision. Technologically, we cannot approach fabrication of an imaging array of millions of pixels each able to discern single quantized interactions - much less in a biological system at body temperature! Albert Rose in his beautiful book Vision Human and Electronic, after noting this ability of the vision process, could only speculate that from an engineering viewpoint an electronic gain of a million or so must be present somewhere in the vision process although he admitted that he had no idea where this might be. Rieke and Baylorfrom a biochemical viewpoint, attempt an explanation but I believe in a very speculative and ultimately unsatisfactory manner
I have put forward in this work a specific proposal as to how I believe this capability comes about in the eye positing individual electronic retinal devices comprising adjacent quantum confined electron spaces of fixed dimension and variable dimensioned light wave-accepting space between them. These individual devices are obviously in the spatio-temporal domain that would support electronic characteristics allowing function at very high speed – perhaps as fast as femtoseconds (10-15 sec) or less. In seeming support of this model, it has been noted by Peteanu et al that the first light interaction step in the vision process occurs in femtoseconds. (A quote from this reference: “These measurements demonstrate that the first step in vision, the 11-cis—-11-trans torsional isomerization of the rhodopsin chromophore, is essentially complete in only 200 femtoseconds”).
Consistent with electronic device operation in this time domain a paper published by a group of us Tove, Cho, and Huth(The Importance of the Time Scale in Radiation Detection Exemplified by Comparing Conventional and Avalanche Semiconductor Detectors) some years ago would seem to be relevant to operation of these devices and may lead to an explanation for the ability of the eye to detect single quantized interactions at body temperature.. Electronic signal-obscuring noise (thermally induced or otherwise) is always a time integrated function. The faster the ‘time constant’ (in electronic terms) the lower the noise.
This introduces the realm of the quantum beyond the eye and presents a physical connection between the biological eye and external quantum physics based reality.
I have excerpted the following text from previous posts where I speculated on quantum and time connections with the vision process. Text is divided into three sections:
a.) Speculation about the idea that the diffractive retina of this explanation might represent the diffraction pattern of an externally perceived “Fourier reality” as proposed by Brian Hagan.
b.) The connections that have been proposed to exist between a quantum reality and biological systems that have been put forward by Penrose, Frohlich and others.
c.) Speculation as to a possible relationship of the Fourier/optical transform of this geometric model to the proposal by Julian Barbour that time itself may not exist , in effect, that the eye views a “timeless reality”?
I. THE RETINAL MOTIF AS THE DIFFRACTION PATTERN OF EXTERNAL REALITY
As Penrose has written, the retina is an extension of the brain and therefore, in my words, serves as the interface between the brain and external reality. What might this new diffractive retinal surface tell us about such external reality? In the formless model that a “photon interacts” light refraction is not considered. I might note here the specific “eight-around-one” motif of rods around cones at 7 1/2 degrees which , surprisingly, is seemingly present in most (all?) biologically evolved photosensitive structures. This realization of a diffractive retinal surface must mean that a frequency or Fourier domain imaging process,is inherent in forming the visual image.. Could it be that this motif represents a “Fourier objectification” of externally perceived realty, i.e., beyond the eye? Or, alternatively, that the retina represents the diffraction pattern of externally perceived reality?
I have made one initial foray into this thicket noting (again discussed elsewhere on this page) a potential association of this specific octagonal motif with a spatially symmetric epitrochoidal figure. On either side the hexagonal symmetry of the all-cone and all-rod regions produces asymmetrical epitrochoids. Thus, spatial symmetry is a characteristic at the peak of the visible spectrum with an asymmetry on either side. Can this have any meaning?
Another starting point might be asking the question: what external reality might such an octagonal diffraction pattern represent? One possibility is an association with quasi-crystal geometric “tilings” of the genre that Penrose has discovered. Certain of these tilings display diffraction patterns with octagonal symmetry. In studying some of these tilings I can almost see a quasi- “added dimensional” effect. Could this be in some way what vision perceives?
Hagan in a whimsical but thought provoking paper proposes that a Fourier transforming process is inherent in overall perception of reality and a few of his words are worth quoting: under his heading “BIOLOGICAL SIGNIFICANCE OF FOURIER TRANSFORMS” to wit:
“The two views of matter , wave or particle, are thus not really divorced, but rather, are inseparably connected through the Fourier transforming process. They are merely different aspects, in the true sense of the word, of the same reality. We will later mention the proposition that the human eye can make these Fourier transformations and so, probably, can the brain”.
Hagan thus saw, what I believe I have now provided a basis for, the actual mechanism of vision.
II. QUANTUM CONNECTIONS
Penrose in his adventure into the “quantum mind” asks “Is there a role for quantum mechanics in brain activity?” He states:
“There is, in fact, at least one clear place where action at the single quantum level can have importance in neural activity, and this is the retina (Recall that the retina is a part of the brain).”
Penrose italicizes “retina” in the original text. He goes on to discuss the above discussed sensitivity of the eye to a few photons (or again in the context of this paper “quantized interactions”) and then proceeds to develop his ideas for a quantum/mind process..
It is my premise that the necessarily complementary quantization arises in biologically evolved photosensitivity not in the incident light but in the “absorbed mass” - the electron. It really doesn’t matter which aspect of the classical/quantum duality is quantized! I believe that it is clear that an observation of the retinal structure leads to the conclusion that I have come to. I find it interesting how a mental construction such as “a photon interacts” told over and over again can so cloud reality and lead for so long a time down blind alleys!
This is perhaps the point to introduce what I believe to be the seminal paper of Frohlich proposing that coherent states characteristic of biological molecules should result in long range order in biological systems, i.e., as Bose-Einstein condensates. I have felt since first reading his paper that such order was ultimately necessary to explain such systems above the usual chemical explanations (albeit that have been very successful up to this time!). I have often quoted an example - the cover of Scientific American some years ago spotlighted the protein ( or enzyme) that in “lock and key” fashion fitted into the DNA helix causing it to unravel or unwind. Now identification of this protein certainly represents an important step but questions occurred to me such as “where (certainly somewhere remote from this point) was this protein synthesized?” …and “how did it come to be ‘delivered’ to this site at precisely the moment it was needed?” These type of questions imply to me the need for some kind of (in military terms) {”command and control” system to order the spatio-temporal aspects of biological processes. In any event this is the aspect of Frohlich’s thought that interested me.
There was one aspect of Frohlich’s proposal that was considered possible to demonstrate experimentally. In a simple calculation he proposed very specifically that bilipid cell membrane would be found to oscillate in the millimeter wave region - at approximately 40 GHz as I remember. In a meeting here in California that Frohlich attended I remember him stating strongly that the fundamental vibrations would be phononic (i.e., mechanical) and were not electromagnetic in nature. I believe he agreed that they might, however, secondarily, cause vibration of charge (on the membrane surface) that could emit/absorb electromagnetic radiation. At the same meeting one experimentalist (from Canada whose name I cannot remember!) did report detecting such microwave emissions and in a rather curious way. His laboratory had been working for months with cell cultures and microwave receivers without success. One day during morning coffee (or tea) break the receivers suddenly began to emit the sounds indicating that they were detecting emissions. It turned out that a technician had inadvertently added nutrient to the cell culture and the cells were in the process of mitosis and seemingly emitting radiation. This raised the intriguing question: are these emissions characteristic of the processes of the living cell ? Following the California meeting I remember that a group from the Los Alamos National Laboratory became interested in duplicating these experiments. I heard later that they had no success.
That is where I believe we stand today in 2002 - although intense interest has persisted around the world, no experimental evidence has been elicited to verify Frohlich’s hypothesis. I always thought that I understood the difficulties. If such a spatio-temporal ordering, information-bearing system were present, nature would by necessity design it to be commensurately as reliable (or secure) as the helical genetic replication process - which we now understand has been passed down free of errors for millenia. Morphogenesis information, for example, would have to be transmitted within and between cells in completely error free fashion totally independent of, for example, the thermal background of the biological system. An information bearing channel formed phononically (coherent excitonically) at such high frequencies “insulated” from it’s external environment by water seems a credible possibility. I remember calculating the attenuation of water at these frequencies and it was an extraordinary number of orders of magnitude! I feel that nature would use such a system with the corollary being that it would be very difficult to experimentally interrogate.
There, however, some indirect evidence supporting the Frohlich hypothesis which I will attempt to recount.
In the 1970’s a group of Soviet investigators reported a series of what they termed “athermal” microwave biological effects wherein certain cellular processes such as mitosis could be affected by extremely low levels of microwave radiation in the same millimeter band that Frohlich had proposed.. These reports proceeded to generate a great amount of interest around the world. The subject of possible mechanisms for such behavior at such extremely low microwave intensities became very controversial - a controversy that probably persists to this day. A second event then occurred. A German group (from, I believe, a Max Planck Institute in Stuttgart where Frohlich was in residence) reported successfully replicating the Soviet experiments. These results were presented at a special meeting held near Munich which I attended, The German group had done their work carefully and their presentation was very persuasive to the point that such low level microwave effects did indeed exist. The Soviet investigators who were invited were precluded from attending because of the politics of the time. I have not followed any subsequent work in Germany but I am aware that the Soviets (now Russians) have introduced “microwave medicine” treating diseases using low level microwave radiation in the millimeter band. I have no idea how successful (or unsuccessful) this effort is but it has achieved some notariety.
Another experimental result that potentially supports the Frohlich hypothesis is Hans Kuhn’s “photon funnel” discussed elsewhere on this webpage. An interpretation of this result is that energy is transduced mechanically laterally in lipid membrane (simulating cell membrane) over many molecular distances from single quantum interactions. The result is similar to a much earlier discovery made independently by Jelley and Schiebe studying chromophoric molecules in solution. They achieved an essentially lossless situation with the optical absorption and emission peaks being separated by only a few nanometers. They termed the effect “resonance radiation” with the entities in solution being termed either Schiebe or Jelley “aggregates”. Kuhn achieved the same result in a more controlled fashion using Langmuir Blodgett methods to incorporate the optically active molecules into lipid membrane - the funnel. A bit of startling intuition by Kuhn was the incorporation of space-filling octa decane molecules into the lipid interstices of the membrane layers which resulted in the shifting of the optical response from the usual, lossy, “Stokes shifted” absorption/emission character to the lossless resonance situation. I believe that this very much supports the proposal that some sort of mechanical solitonic vibration is involved. A seemingly important connection of the funnel result to actual biological cell membrane can be made in that nature inserts the cholesterol molecule into exactly the same interstitial lipid spaces as Kuhn’s octadecane!
I would mention the proposals that have been made by Hammerof et al proposing that the microtubules inherent in living cells are somehow involved in quantum / Frohlich processes… and on development of theories of a quantum consciousness..Microtubules are mechanical structures that are constructed (and deconstructed) of inert tubulin by the cell in it’s various stages of mitosis etc. This group would propose that there is something fundamental about the cytoskeleton so produced. I don’t agree that there is anything fundamental about these materials or structures. I would believe that these, again mechanical, structures may serve as “high frequency, information-bearing, solitonically-transmissive, conduits” that would seem to be a necessary part of Frohlich’s concept.
III. ON THE FOURIER TRANSFORM AND TIME:
This transform brings spatial information into time coincidence at the focal (or Fourier) plane of a condensing optical lensing system such as the eye. Feynman in “QED - The Strange Theory of Light and Matter” notes that this is the fundamental purpose of such an optical condensing lens. The thinner section of the periphery of the lens slows light less than rays passing through the thicker center with the result being that each ray arrives at the focal point of the lens at the same time - assuming, importantly that a single wavelength is involved.
At first blush such time coincidence would seem to be an absolute requirement for forming the image seen by the eye (or any image), i.e., all information about the image must arrive and be processed into the final form contemporaneously. This much must certainly be true. But…is it possible that such time coincidence might represent a timelessness as perceived by the retinal surface? It seems to me that the concept of “coherent time” might just as well be seen as a negation of time. The idea of a reality without time is the subject of a book by Julian Barbour that I have found fascinating. I won’t go into detail about Barbour’s ideas here but the question that the above poses might be: are we moving through a timeless “many universe” reality and might the eye in this new view be the vehicle for such perception? In fact more question marks!
A particularly nice line from Barbour’s book - “the instant is not in time - time is in the instant”
On the near-in subject of the relationship of the transform to the retinal structure proposed - an optical lens is defined as a “Fourier transforming device”. In fact the lens actually performs a second, “inverse Fourier transform” in re-creating the original spatial image at the image plane. Thus the image formed by a lens is defined as “the Fourier transform of a Fourier transform”. Phase information is, however, lost in the latter image transformation. Phase information is only present at the focal or Fourier plane. The photographic images that we are accustomed to seeing contain only the amplitude information. There is a medium that does preserve phase information - holography - but we will not go down that line of thought here.
One must emphasize that the function of the extended retina that I propose is to spatially separate the electromagnetic wavelengths of the visible spectrum. This is not the “frequency space” of the Fourier domain.
It follows from this model that the retinal surface satisfies the Fourier equation at each point, i.e., both light amplitude and phase can be determined at each point. This implies, to satisfy the Fourier equation, that the Fourier (or focal) plane and the image plane must be in coincidence. In a real sense then an actual image is detected on the retina.
The obituaries of the New York Times of this date report the death of Alvin Marks at 97 years of age. I have noted that it was Dr. Marks’ proposal for “antennas for visible light” that provided the initial inspiration for this work. He seems to have been, as the Times notes, a man of truly large scale imagination.
It seems ironic that, although I am aware that controversy existed between Alvin Marks and Edwin Land concerning the invention of light polarizers, the fundamental antenna insight of Marks provides the basis for an explanation of Land’s extraordinary color vision experiments!
The finding of a direct relationship between geometry and light wavelength on the retinal surface may be the most fundamental insight of this work. It is seen that the exact center, i.e., ~550 nanometers, is geometrically defined at a retinal eccentricity of approximately seven degrees. This degree of retinal angle then becomes a fixed wavelength referencefrom which all other wavelengths can be compared in the vision process synthesizing the hues of color. Edwin Land brilliantly deduced the presence of just such a reference in his comment “…we have learned that the eye must have a fantastic mechanism for finding a balance point within a band of wavelengths”. It seems clear that the presence of such a fixed reference provides an answer to the longstanding conundrum of the unique “color constancy” of vision - again, as Land proposed. We all “see green” because we all have the same sizes of retinal receptors and thus the same geometrically determined color reference!
The eye is then not to be viewed as a kind of laboratory spectrometer that selects colors from different classes of cones but rather as a result of evolutionary biology where the fundamental physical principles of the diffraction of light and geometry are directly related to produce vision!
The following is an historic figure from Pirenne (1) of a drawing made of this reference point on the retina. Note that this is the first point where octagonal symmetry is present. This is the eccentricity where sufficient rods have been introduced to completely surround each cone and a symmetrical structure results. On either side (i.e., inwards towards the fovea and outwards towards the peripheral retina) rods and cones are statistically distributed that has caused such confusion in the vision field attempting to find some order.
(1) I wish that that readers would review this seminal reference: “VISION AND THE EYE”, M.H. Pirenne, The Pilot Press Ltd., London, 1948
A NOTE REGARDING THE ABOVE FIGURE - I would assert that the figure represents, in the living state, a perfect octagonal symmetry since the ratio of the diameter of cones to rods is an exact ratio (1.8:1) to support that morphology. The microscopic sections that Pirenne must have used to create these drawings (and in the freeze-dried sections used in contemporary electron micrography) had been dried unavoidably introducing spatial distortion. GCH
This line of thought relating geometry and light wavelength leads directly to the processes involved in the evolution of the eye. It is obvious that the eye is the direct geometric materialization of the fundamental physics principles of the diffraction of light. If anyone wants to introduce “design” into this they will have to go back one step further into designing the fundamental laws of physics!
And further, if one doubts that the basis for this explanation that chromatic aberration of the lens of the eye provides the information used in the vision process, I will quote again from George Wald’s “Blue-Blindedness” paper written in 1967 about which I commented yesterday.
“Any lens made of one material exhibits chromatic aberration; it refracts short wavelength light more strongly than long wavelength light, and hence brings blue light to a shorter focus than red. Color-corrected lenses can of course be made by using two glasses differing in refractive index; but, so far as is known, no animal has yet succeeded in developing a color-corrected lens. Though the cheapest of cameras have color-corrected lenses, the lens system of the human eye – as Newton observed – has no color correction whatever”
Corroborated by this statement, and in the light of my geometric explanation, it is obvious that the eye uses chromatic dispersion (my term) to form the visual image (in the Fourier frequency domain). This has heretofore been incorrectly, with unfortunate consequences, termed an aberration in the history of vision science!
Issac Newton saw this! Why has it been disregarded in vision science?
Please read this paper (J. Opt. Soc. Am, Vol.57, No.11, November 1967). The retina described by Wald corresponds almost exactly to the retinal response of my explanation by making the simple substitution of the term“rod-rod appositions” for “blue-sensitive cones”.
Even his opening paragraph:
“In 1894 Konig and Kottgen reported experiments designed to show that the central region of the normal human fovea is blue blind (with reference). Konig had come to believe the sensation of blue is excited by rods…..”
One should also read George Wald’s Nobel Lecture at noting his Figure 15 that defines retinal response very much as I explain.
At the risk of being accused of taking Wald’s thoughts out of context I will transcribe some sections of his text. I believe that these summarize the thrust of the paper.
From the Abstract (p.1289):
“The blue cone system falls in sensitivity from the border of the photopic zone – the functionally all-cone areas – to a minimum, usually to extinction, at it’s center”…”Also the red – and green cone systems display the opposite gradient; their sensitivities decline regularly from the center toward the borders of the fovea and beyond”
(Wald defines the “photopic zone” as being “dominated by cone vision” and extending to “visual angles of at least 1.5 degrees”. This represents the all-cone fovea where in my explanation cone/cone appositions form the “primary” long wavelength (or “R”) peak and, additionally, precisely define the long wavelength limit (~700 nm) of the visual band.)
The above quote describes the plan of light interaction on the retina as I define. This is undoubtedly the basis for the retinal sensitivity curve that Wald presented in his Nobel lecture (Fig. 15). It is truly beyond me how anyone seeing this, i.e., that color sensitivity is segregated into specific areas or “rings” on the retinal surface did not think to relate this diffractive surface to the wavelength refractive properties of the eye!
From p.1290..My thoughts have been anticipated!
Wald, (after calling it a misconception), quotes:
“Wilmer (1) had thought to explain color vision in terms of only two kinds of cone, or cones, and cone-like rods, the third color mechanism, that for blue, involving the cooperation of ordinary rods Hence, he too expected to find no blue receptors throughout the entire photopic area…”
(1) E.N.Wilmer, Nature 153, 774 (1944), and E.N. Wilmer, J. Theoret. Biol., 1, 141 (1962))
Wald goes on to say that “the photopic area of the retina contains large numbers of such blue-sensitive cones”. This area does contain a (low) density of “blue-sensitive centers”. What I believe that he is actually observing is the statistically small, randomly distributed, density of rod/rod appositions in this critical area (~1.5 degrees) of the retina where rods are just beginning to intrude on a rapidly declining cone density in the retinal morphology.
From p.1294:
“It seems therefore that the absence or near-absence of blue receptor function is characteristic only of the center of the fovea. It is a matter, not primarily of size of field, but of foveal topography”
From p.1296:
“The general gradient of cone concentration in the fovea therefore runs counter to the gradient of blue-cone sensitivity. At the center of the fovea, where cones are most dense, blue-cone sensitivity is minimal, and blue-cones are usually entirely absent. Conversely, at the borders of the photopic area, where the blue-cone sensitivity is highest, the total number of cones has decreased markedly. This opposed distribution is reflected in a converse pattern of relationships that involve the red and green cones”
From p.1298:
“…whereas the sensitivities of the red and green-mechanisms are highest at the center of the fovea, and decline regularly with distance from it, the blue cones show just the opposite gradient of sensitivity, rising from a minimum at the center of the fovea to one half degree to one degree out…”
From p.1299 where Wald recognized the problem of chromatic aberration in the eye:
“Any lens made of one material exhibits chromatic aberration; it refracts short wavelength light more strongly than long wavelength light, and hence brings blue light to a shorter focus than red. Color-corrected lenses can of course be made by using two glasses differing in refractive index; but, so far as is known, no animal has yet succeeded in developing a color-corrected lens. Though the cheapest of cameras have color-corrected lenses, the lens system of the human eye – as Newton observed – has no color correction whatever”
Henceforward , I would propose terming this “chromatic dispersion” instead of considering this effect an aberration
From p.1300:
What we take, therefore, to be normal, trichromic vision is the particular property of an annular zone of the central retina, lying between the blue-blind fixation area and a red-green blind zone some 20-30 degrees out. The special importance of this central zone is that we depend upon it almost exclusively for all phase of photopic vision, and that, all testing of color vision is confined within it, rarely extending more than 2 degrees beyond the fixation point”.
This work, put very simply, reinterprets the long accepted (i.e., appears in almost every vision textbook!) 1935 retinal morphology data of Osterberg in terms of modern physics and nanotechnology and arrives at an entirely new paradigm for the vision process. An example of vision science being stuck in the past - it was noted for me even within the past week that a contemporary view is that retinal receptors “act as waveguides”. Receptors do act as waveguides, but, in modern terms. When the diameter of such a guide is reduced to the micron and sub-micron dimensions of retinal receptors light travels outside of the guide instead of internally as in larger diameter fiber optic light guides that we now use in the optical communication field (see references in previous comments). This single point validates my explanation for light interaction with the retina!Please…. bring physics, and more precisely quantum and nano technological thought, into vision science!
Any new paradigm, theory, hypothesis etc. must be predictive to be valid. I have sketched out over the history of this work how this new view opens many new lines of thought into the vision and even plant photosynthetic processes and, further, into more esoteric areas of physics and biology. One of these is a provisional linkage of the vision process with the physics of quantum reality in my proposal that an actual physical mechanism exists linking the observer to emerging concepts of an external quantum environment. A physics overview emerges that encompasses the fast time domain characteristic of the quantized interaction of light with the outer segments of the retina and subsequent, slower, biological processes that operate within the human nervous system and brain. These thoughts I believe will ultimately have implications to the conundrum of human consciousness. I will outline in the following a number of these areas here but be clear that this certainly does not constitute a complete or even prioritized listing:
1.) It becomes clear that the eye forms images in the Fourier frequency domain, i.e., that the retina is a diffractive surface that processes both the intensity and phase of incoming light. This opens up many new lines of thought. We have no comparable imaging technology in the visible range of wavelengths to accomplish this. The recent discovery in the solid state of a visible light interactive silicon nanostructure (“porous silicon”) that uses the same light interaction mechanism as the retina provides a starting point for development of a series of new imaging technologies. At this stage of it’s development the technology of porous silicon provides only the high efficiency initial light interaction function and not the comparator (phase decoding) ability of the retina of the eye. It should certainly be possible with development to add the necessary microcircuitry in the sub-porous silicon substrate to replicate this capability.
2.) The diffractive retina explains Edwin Land’s body of experimental work on color vision. It will now be possible with this new understanding, that Land could not have known, to expand our knowledge of how the hues of color are really perceived.
3.) The truly fundamental finding of a geometrically determined reference point at 7-8 degrees of retinal eccentricity that defines the exact center of the visual band! It is nanostructural geometry that determines light wavelength in the vision process. Nothing like this has been seen before. This for the first time provides a logical explanation for the color constancy of the vision process.
4.) The many aspects of fundamental geometry leads to the ability to predict the characteristics of the visual system of any species photosynthetic plant or animal. For example, I have proposed that if two sizes of photosensitive receptors are present in a photosynthetic morphology the bandwidth (as shown in the human retina) will be determined by the ratio of their diameters. The absolute size of the receptors themselves will determine the position of the band of light interaction. I have shown that this seems true for species as varied as fish and insects.
5.) This paradigm predicts that at least two diameters of receptors are necessary to provide the imaging (or sensation) of color. Only an admixture of two sizes can produce the three “primary” wavelength peaks necessary (Land again!) to process the hues of color.
6.) The strange finding that the same octagonal symmetry (rods-around-cones at 7-8 degrees of eccentricity) is characteristic of the retinal morphology of seemingly all species from honeybees to crabs (the references of Snyder et al).
7.) The concept that the eye may not be the passive “camera receiver” that has for so long been assumed, but, may actually radiate a light signal back into the environment. This follows from the fact that antennas – as light interacts with “optical antennas” on the retina – transmit equally well as they receive signals (information). Following this, I have proposed that the well understood principles of optical phase conjugation are involved that would result in the radiation of this signal back along the exact path upon which it entered the eye. This insight leads to a “connectedness” between the observer and the observed that may, in the view of the author, have relevence to the subject of consciousness.
8.) It becomes evident that quantum physics must be introduced structurally into the science of vision. I believe that I demonstrate, for example, that light interaction with retinal outer segments occurs in femtosecond time (there is really a great deal of experimental data corroborating this) and that this forms the basis for the, again understood but never explained, ability of the eye to process single photon (or as I would term “quantized interactions”). It would seem, and has been proposed that information exists and is processed in vision in this (quantum) time domain, i.e, the time domain associated with the frequency of light. I would believe that the “Heisenberg cut” that defines the point of demarcation between quantum and classical physics may occur at the retinal outer segments of the eye. The function of the processes of vision that follow this interaction are, in my view, to “slow down” visual information to the slower time domain of classical physics, or in other words, to human nervous system proportions.
9.) I believe that it is possible to replicate the diffractive pattern of light interaction of the retina on silicon using the above mentioned technological discovery of visible light interactive “porous silicon”. This would be accomplished in experimentation imaging the longitudinal chromatic aberration of the solar spectrum passing through a condensing lens onto a silicon surface while it is undergoing the porous silicon electro-etch process. Such an experiment using the solar spectrum would provide a fundamental demonstration of how a primordial photosensitive organ of vision evolved simply as a physical embodiment of the principles of the diffraction of light and not through any concept of “design”. I believe that this will be a very fundamental experiment and I hope that someone will carry it out.
As anyone following this work will have noted, I assert that light interacts on the retina in three distinct geometrically defined regions formed by appositions of the intermixture of cone and rod receptors and not within the receptors themselves. It even becomes possible to view the retina abstractly as a logically ordered array of generic quantum confined electron centers. It may even be helpful to completely do away with the terminology of “cones” and “rods” and view them simply as elements that provide the proper logical “geometric spacing” between the generic (essentially retinal molecule) energy absorbing electron centers.
The three interactions are as follows:
a.) With the hexagonal matrix of cones that form the fovea with this interaction defining the exact long wavelength (“red”) limit of visual response. The fovea is “blue blind” as Wald correctly found!
b.) With the admixture of cones and rods where, at 7-8 degrees of eccentricity, the density of rods is sufficient to completely surround each cone to form a perfect octagonal symmetry. This, again exactly and geometrically, defines the center (“green”) wavelength of the visible band. This geometrically fixed point provides a fixed reference on the retinal surface from which all other wavelengths can be compared in the visual image formation process. This array of octagonal “rods-around-cone” assemblies have been mistakenly termed “M cones”.
c.) With the, again, hexagonal symmetry of the predominantly rod-containing region of the peripheral retina that defines the exact short wavelength limit of visual response.
(I must parenthetically note: 1.) no one as yet seems to have seen my point that the only geometric basis for the octagonal symmetry of the mid band centers is a receptor size ratio (i.e., the diameter of cones to rods) of 1.8:1. This is the only ratio that can result in the octagonal symmetry that is observed and this ratio corresponds to the visible band, i.e., from 700 to 400 nanometers and, 2.) a reminder that the three wavelengths detected as above are “primary” (as deduced early in the history of vision) but are not yet “colors”. The hues of color are determined by comparing these wavelengths in the manner deduced so brilliantly by Edwin Land. Through all of this I am reminded again of the quote attributed to Einstein that “All is Geometry”)
Thus… three narrowly tuned wavelength-receptive regions are defined on the retinal surface.. What is the parameter that varies across each region? At first thought it is the density of receptor sites.But secondly, it is the perfect symmetry of each region that in addition to defining density of sites is related to the point of peak light absorption. One moves from the perfect (large receptor) hexagonal symmetry of the fovea to a perfect octagonal symmetry at 7-8 degrees to a perfect (small receptor) hexagonal, symmetry of the rod containing peripheral retina.
Thus the retina progresses at increasing eccentricity from hexagonal to octagonal to, again hexagonal symmetry.
It is then perfect geometric symmetry that defines the peak of each wavelength absorptionregion.
A diagram from Pirenne that I have previously used showing the perfect octagonal motif at the 7-8 degree retinal eccentricity.I again humbly submit that this is the basis for the “clumping of M cones” that Masuda et al have recently reported (see previous Comments for the reference).
I have not time to go into it here but geometrical perfection combined with the sub-optical wavelength dimensionality of these receptor centers results in a density that precludes overlap of photon (read “quantized”) interactions at each center resulting in the high (nearly perfect) light interaction efficiency in these regions. This in turn leads to an explanation for the ability of vision to detect single photons (or, again, quantized interactions.
A poster/paper (3832/A375) was presented at the ARVO 2008 Annual Meeting “Arrangement of the Human Trichromatic Cone Mosaic in Peripheral Retina” authored by O. Masuda, H. Hofer, J. Carroll and D.R.Williams. I interpret this work extending the imaging methodology developed by the authors (and previously by Roorda et al) to larger retinal eccentricities, as being in some way a response to my repeated requests that this measurement be made. But….who knows?
I humbly submit that their results seem to verify my projection in their findingof a “clumping” of, what they (erroneously) term L and M “cones” at retinal eccentricities of 10 degrees. They note that this represents the first instance where the packing arrangement of cones is distinguishable from randomness, i.e., that a spatial order is observed. Their exact statement “Previous studies have concluded that the packing arrangement of L and M cones near the center of the human fovea is not distinguishable from random in most eyes”. (does this mean that the packing arrangement in“some” eyes is not random? – please supply a reference?).
I believe that the basis for what they are observing follows directly from my observation that iscalculated directly from Osterberg’s measurements of retinal morphology showing that the maximum (at this point complete!) degree of spatial order appearing as a motif of eight rods surrounding each cone. This perfect geometric array following Osterberg occurs near this eccentricity (really at 7-8 degrees but they are close enough). The interplay of cones and rods at this eccentricity is not statistical anymore but completely ordered! I have proposed that this octagonal motif forms a fundamental (termed “primary”) mid band (“green” or in their terms an “M cone”) light interaction point on the retina. In my explanation this complete degree of geometric spatial order translates into the peak of intensity of the primary mid band wavelength and forms the 550 nm wavelength mid band reference point on the retinal surface. I have proposed that the identification of this geometric reference forms the basis for the color constancy of vision. The eye interprets the exact middle of the visual band geometrically! The retina is not a spectrometer!
I will not go into this much further only noting that the sample size of their images is so small that the statistical nature of the distribution of cones and rods is seen (Osterberg again!). This is as to be expected and they note this. The first degree of order (or “clumping”) that they observe at the 10 degree eccentricity in these statistically small images represents the “tip of the iceberg” of the spatial order that exists at this eccentricity. Their quest for an ordered “mosaic” on the retina, and any idea as to how the randomness that they have observed (until now!) could lead toan image formation mechanism, totally eludes me. I would like to see the reasoning behind this?
The spatial resolution of their imaging methodology and the question why they do not observe rod receptors? I have addressed this in a previous Comment. Suffice it to note that they claim 2 micron resolution which would be approximate the diameter of the inner segment of a single cone and should be sufficient to image rods .
Again, I would claim what they are actually imaging at this eccentricity is a motif of eight rods around each cones. This “M cone” should be really be termed an “M wavelength detection center”
Added on 5/14/08
The authors also undertake a curious (to me) effort to measure the distances between cones apparently to verify the randomness of the distribution. I do not understand why they apparently want to verify what already is, and should be, apparent as the statistical randomness following from the Osterberg morphology data? Their words: “We evaluated the packing arrangement of the 3 cone classes by comparing frequencies of distances between all cones of the same type with those expected based on a random pigment assignment rule”
To be clear - the foveal region that contains > 99% of cones on the retina, and where they want to see a differentiation of these cones into “classes”, is totally “L wavelength” sensitive. Then as rod receptors begin to intrude into the receptor array at the edge of the fovea at eccentricities of one degree a statistical distribution of L and a few M (cone/rod appositions) begins to be seen. At this point if one does not want to believe the data of Osterberg see the figures of George Wald! The author’s measurements until this paper were made at eccentricities of one degree and they observe exactly what they should observe. I would note on the subject of “S” or blue sensitive “cones”, again statistically, here and there an apposition of two adjacent rods will be observed ..and voila, an “S” cone! This is the explanation for the strangely small density of this type of “cone”.
My finding of the three primary wavelength peaks on the retina follows from a simple counting of receptor appositions using Osterberg’s morphology data. Any grad student could do a statistical analysis of the presence of rod/rod appositions in near foveal region (at an eccentricity of one degree as measured by Roorda) and I project that the density so calculated would correspond to these measurements of “S Cones”.
