Rethinking the Process of Vision

November 28,2006

Following an intense discussion with my son over the weekend on this subject….I had earler proposed (speculatively?) that as, in engineering terms, antennas are capable of transmitting as well as receiving (or detecting) electromagnetic radiation, the retina, and thus the vision process, might in reality be an active one instead of the passive role that has been historically assumed (“the eye as a camera”). Further, I had proposed that the retina as I conceive it acts as (or is “capable of acting as”) a “phase conjugating mirror”, thus re-radiating a received optical signal back along the exact path upon which it entered the eye. This follows directly from identification of the retina as the Fourier plane of the optical system of the eye. The first time that I realized this my thoughts went immediately to the idea of consciousness…identification for the first time of a real physics-based “connectedness” with external reality perceived by the eye, To what purpose? (my son asks) and I cannot provide an answer..but a real connectedness none the less…????

Might such a connectedness be the basis for conscious introspection by the signal-accepting, brain / ”central processor” lying behind the retina?

I see the tree a few feet from my window..or rather, I see the light reflected from the tree. From the perspective of my retina this image is “from the past”…the light reflected to my eye “left the tree” some ten or twenty nanoseconds ago. If my retina re-radiates a signal back (albeit at the photon level) to the tree (along the same path via the phase conjugation process) the time that it arrived at the tree would be “in the future” relative to the image formation process on my retina. One then conceives of a “timeless apex” at the point of my retina balancing past and future. Interesting..in the context of the definition of a Fourier plane and/or the timelessness thoughts of Julian Barbour.

If such a connectedness were true how can we see “back billions of years in time” in looking at the stars in the sky? This has, however, always been a contradiction…”seeing into the past…”. Perhaps these objects arent’t really as far away as they seem…?
How about that!

Might it be (and it seems so) that our consciousness only extends to the point where a light signal can be returned within the biological image processing time of the eye? If this is 1/30 of a second or so that would correspond to a distance of miles…. which is pretty much the limit of our vision (on a clear day)!

One will argue here (as my son did) that these “connectedness” times are much shorter than the “biologically controlled signal processing time” of the eye and these considerations are therefore inconsequential. They are nonetheless real.

More to come…and great non-peer reviewed fun!

GCH

The reader will have noticed the new, more intelligible, format designed by Bert Mahoney for the site replacing the rather crude layout that I, alas only a poor physicist, was able to cobble together. The chief problem it seemed to me was that, with the chronological addition of ideas (under “Additional Thoughts” and now termed “Comments”), those that I considered of greater significance disappeared “down the queue” receding into the distant past and would probably have been missed by the reader. An attempt to solve this problem has been the addition of “Archived” Comments by year of entry…but this still doesn’t completely solve the problem. What I will do in future Comments is to spotlight the “important old” and provide a link to them. I hope this works!

The site is composed of the following separate thrusts and discussions: 1.) an explanation of the basic antenna/geometric premise for light interaction with the retina addressed generally to the biological element of vision science, 2.) discussion of the physics and/or optical image processing (i.e.,engineering) underlying the premise, and 3.) touching on the medical implications of the concept whenever I identify them, and, 4.) speculative discussion (the most fun!) of new lines of thought that seem to be made possible by the idea. These include thoughts on consciousness and the meaning of time. Using the Search function and pointing to: “consciousness”, “time” “quantum” or “Fourier” will lead to some of these.

I note in passing that I have found that there seems to be precious little physics discussion in contemporary vision science!

GCH