Showing posts with label vision. Show all posts
Showing posts with label vision. Show all posts

31 August, 2022

The Charles Bonnet Syndrome


This paper is taken from Special Issue 70 of SHAPE Journal: Truth and Illusion


The Charles Bonnet Syndrome

Discoveries of the Vision/Brain System caused by significant Loss of Vision



I am a scientist and an octogenarian. I currently suffer from an affliction known as Charles Bonnet Syndrome, caused by macular degeneration.

“Charles Bonnet syndrome (CBS) is a disease in which visual hallucinations occur as a result of vision loss. CBS is not thought to be related to psychosis or dementia and people with CBS are aware that their hallucinations are not real.” Rarediseases.info

As an extensively-experienced researcher in both science and philosophy (and their inter-relationships, and cross- causalities) - as well as being a prolific investigative writer of serious academic papers in both of these areas - I felt I was in a unique position to shed some light on this disease, and the insights it offers into how we understand the world visually.

I have a particularly well-endowed background to both accurately describe the changing symptoms involved, and (it seems to me), I possess a unique and necessary ability to draw conclusions, wholly absent from either the usual sufferers or medical practitioners - to play a role in extracting more informatively, exactly what is going on in this less than perfect, and undoubtedly failing system of diagnosis and treatment.

Indeed, it reminds me of the conclusions drawn, many years ago, by V. S. Ramachandran - whose work I have followed closely - from the clinical evidence of both Blind Seeing and Visual Neglect, concerning the Brain Functions involved, and dependable conclusions on how hallucination is actually a fundamental part of vision.



V S Ramachandran



My credentials are actually somewhat understated in the above brief description of my professional career. The last 20 years of my life have been dedicated to understanding the philosophical limitations of all Pluralist Science - a pervasive logic which sees laws as separable, but is blind to the dynamics of Qualitative Change, due to its primary methods of analysis - holding things still and making extractions. Plurality regularly generates untranscendable contraditions and impasses in our understanding, but science is fundamentally pragmatic and finds workarounds, but without ever resolving the underlying problem of its failure to deal with real-world change.

This is certainly relevant to understanding my condition, as the Charles Bonnet Syndrome is about the dynamic interface between signals from cells in the retina of the Eye, to regions of the Brain with the capabilities to construct adaptable, and developable visual models (“as cerebrally-viewable images”), which is what we actually “see” and consider, and which is both constantly-updateable and stable as a kind of “movie” in our minds, and could be called upon when required in both the immediate present, and the distant future as visual memory.

And this is well beyond what any Pluralist Science can possibly cope with! But, what could be the requirements of an alternative Holist Science, one that could comprehend this mental movie? For, it certainly WILL NOT BE as a sequence of stills (as in Film) OR even as a sequence of mini-movies (as in Analogue Video)! NOTE: I studied the dynamic qualities of both of these electronic media as part of my extensive research into Dance Education and Motion Studies, with Bedford Interactive in the 1990s.

What will it have to be then, to be useable, as we know it is in the brain, and specifically, how will it perform as evidenced by the actions of The Charles Bonnet Syndrome?

And the more incidents I experience due to the condition, the more complicated and various are the functions that are demonstrated. So, rather than using the selected examples from a clearly diverse range of accounts, some of them are either remembered or can be somewhat embroidered - to avoid the misleading consequences of such misleading evidence - I will instead commence my own contributions with a range of my own experiences, as a professional scientist and multi-discipline researcher, only recounting what I have personally experienced, and also judging what I consider valid enough to be included, if and only if, an explanation is forthcoming!

Let me start by describing the various types of hallucination I have experienced myself.


1, The Mini Movie

This invariably occurred upon waking and opening my eyes. But, it wasn’t a misinterpretation of “things- seen”, for it was there wherever I looked, and was always containing the very same subject matter. But, uniquely, it was always in full-detailed colour and excellent resolution - a perfect illusion, always of the same restricted scene, but with minor differences. It was always of a Victorian slate roof, containing one or two brick-built chimney stacks, surmounted by ceramic tops, all with the same kind of zig-zag heads. And, invariably, there would be a branch of a tree, with large glossy leaves being blown about in the wind. But that was it! In a way it was beautiful, but like a repeating movie scrap! Surprisingly it was always framed, as if seen through a window. and wherever Iooked it was there! But it always soon faded and was gone.

2, The Misinterpreted Tile

This, latterly as my sight has become very poor, is clearly a rather poor version of something actually seen, but in these cases it fills-in where my macular is detecting nothing. Very recent versions occur when a glance to a new place immediately sees a hole (that is - nothing there at all), and then rather quickly fills it with the circumstances close to the tile from actually seen views near to that hole! But my looking elsewhere and using the part of my right eye macular, still partially working, you can confirm that the patch is wrong.

With further deterioration, it has now become a major problem, as it can deliver buildings or trees to the view, when it should be the sky!

3. The False General Tiling

In relatively poor lighting conditions, a misinterpreted patch from an extended same view, will then fill-in-and-maintain, wherever I look in that extended view with a regular tiling of the same “tile”, this giving it a pattern which isn’t actually there.

4, The Simplified Tiling

If I look intently at a patterned surface or curtain, it simplifies successively (if I continue to stare) into a series of different, but repeated sets, wherever I look. And, surprisingly, the images, then consist mostly of black lines upon a white background, but they are so beautiful. It’s a real shame I can’t “capture them”!


Now, as with Ramachandran’s conclusions upon brain-activity areas, with normal seeing, the revelations of the Charles Bonnet Syndrome sufferers, as seeing functions were damaged, also throws light upon how the brain plays various creative roles in normal sight too.

To consider these phenomena upon sound bases, though, we have to be clear upon the differing functions of both the relatively tiny macular areas of the Retina within the eye, and the much larger non-macular area, which occupies the whole of the rest of the Retina. It has become clear that we actually see literally ALL detail via the Macular part of the Retina - these are the only areas naturally delivering everything we see in any detail: whereas the rest of the retina is only well equipped for detecting the movements seen by our eyes.





Indeed, detail updates for any achieved brain-image of something seen, can only take place via the macular! The macular must be moved about to build up the picture of a scene in the brain.

[Whereas, as the focus of seeing is moved elsewhere, a simplified-and-unchanging version is always left behind in all past positions, in the now non-macular areas of the Brain-image. Clearly that part of the brain-image must all be derived from prior macular attention to such areas. The non-macular brain-image is therefore initially composed of “macular-sized patches” delivering the whole of the non-macular brain-image]

So, immediately, anything no longer being picked up by the macular will NOT now show moment-by-moment changes there. Indeed, it will show what was there the last time we looked at that area, via the macular, BUT, as the non-macular does deliver movement, it will have, in some way, to update that non-macular view!

But in addition, evidence from Charles Bonnet sufferers, reveals an extra fill-in function, by copying in a now- absent-view from immediately adjacent areas.

While the rest of the non-macular view is always rotated according to a previously-learned “algorithm”, while still updating movements anywhere upon that area, as our view is moved on.

Now, some of the built-in mechanisms for updating the brain-image of a looked-at-view, have only been revealed by sufferers of the this Syndrome, particularly when the incoming image delivered by the eye is deemed inadequate, for the initial solution is to fill-each-gap with the same content, indeed as that of a close nearby spot (either a reliable one, or a compromise inaccurate one).

In the latter case, it is revealed to be from the immediately priorly-vistited “patch” - so that in an erroneous viewed area, the moving glance of the viewer will merely leave a trail of identical patches determined by the eye’s line of scanning. So, if I as a sufferer, are not sufficiently careful, the brain can fill whole areas of sky with a fiction of recently observed trees!




EDITOR’S NOTE:

Charles Bonnet Syndrome is a very specific form of pareidolia - or visual apophenia. This means that it is evidence of a general tendancy of the brain to invent things in order to make sense of random or meaningless information. For Charles Bonnet sufferers, this is experienced as profound hallucination. In people without sight loss these mechanims are still present, but largely hidden, as the stream of visual information given to us by our eyes is complete enough to correct any mistakes or strange inventions made by the brain. Seeing faces in the dark is an example of pareidolia working under normal sensory conditions. People undergoing prolonged sensory deprivation can also experience hallucinations, similar to Charles Bonnet sufferers, as we see with a phenomenon called Prisoner’s Cinema, in which inmates kept in solitary confinement begin to see strange light shows on the walls of their cell.

06 October, 2020

Special Issue 70: Truth and Illusion



Read Special Issue 70 of the SHAPE Journal


This special edition of the journal is co-authored by science philosopher Jim Schofield and artist researcher Mick Schofield.

Art, Science and Philosophy all share the same ontological quest of approaching truth, albeit with very different methods, ideologies and results, but there are countless pitfalls along all three roads, and many of them share the same origin. All three rely on appearances and forms as their basic material. Even the most apparently unmediated of these, are still Abstractions from the material world, and can already be deceptive. And that is long before we start categorising, rationalising, manipulating and combining forms, in all the elaborate ways we have learned to do, but which ultimately push these forms further from their original contexts in reality.

We primarily rely on our senses to confirm whether forms are true or not, but many philosophers over the centuries have shown that this can be a mistake. Optical illusions are often used to demonstrate how we cannot trust our senses - that there is some barrier between us and the truth of the material world we observe. However this is a limited view - it fails to take into account the fact that most of the time our senses serve us very well, we find our immediate realities completely intelligible. They also fail to take into account a key paradoxical fact, that illusions can actually give greater access to reality, than our senses alone can offer.

Think of the mirror, for example. Until we encounter a reflection we have no idea what we look like.

A reflection is certainly an illusion however, and one we routinely trust to tell us the truth, despite the fact that it flips the entire world front-to-back. For Jacques Lacan the mirror illusion was fundamental to how we see ourselves and our relationship with the reality around us. The mirror stage is a crucial phase in the development of human infants, where the ego begins to develop as we see ourselves as an ideal image, and fundamentally separate from others for the first time. Before this, according to Lacan, we live in the Real Stage, where we are only concerned by our immediate bodily needs and a lived unity with our mothers.

Another crucial illusion we rely on to access information about ourselves and the world, are moving pictures. These are based on photography, which also makes clever use of mirrors and tricks of the light, to present authentication of how things look. The photographic illusion, while synonymous with evidence, is compounded when we use machines to play back one photograph after another. All moving images present a basic illusion of movement - a motion that is constructed from a series of stillnesses. This isn’t how motion works in reality at all - and yet, we have simulated it well enough to trick the eye with ease.

The illusions of moving images provide us with reliable evidence of things all of the time - augmenting our senses and providing access to aspects of reality we could never approach without such technological prostheses. Marxist theorist Walter Benjamin talks about this in his famous essay on The Work of Art in Age of Mechanical Reproduction, calling this new technologically-aided sense, the optical unconscious.

But there are certainly limitations to our amazing inventions. We become so reliant on them for information, we cease to notice their shortcomings and distortions of the truth. Jim Schofield’s research with Bedford Interactive into the capturing of dance on video for motion study, showed how much dynamic information is lost when we rely on a series of stills to record it. His use of Zeno’s paradoxes and dialectical reasoning in attempting to resolve the problem shows this is more than just an issue of inadequate technical solutions. The very contradiction of trying to understand motion through stillness was bound to surface sooner or later, even if this particular illusion is adequate for most purposes.




This conundrum also reminds me of Henri Bergson’s view of our cinematic view of reality - another philosopher influenced by Zeno. Bergson used the “cinematographical apparatus” as an analogy for how the intellect attempts to deal with truth - always fragmenting, abstracting, analysing phenomena into discontinuous constituent parts, and then attempting to understand the dynamic whole from these debris.

“Such is the contrivance of the cinematograph. And such is also that of our knowledge. Instead of attaching ourselves to the inner becoming of things, we place ourselves outside them in order to recompose their becoming artificially.” Bergson, 1907

The video camera is a science experiment. It takes small pieces, samples, data, and tries to understand the dynamic whole. But something is always lost. Such illusions can be very useful, the difficulty then lies in working out what isn’t translated, and the extent to which we might be kidding ourselves.

As Jim Schofield investigates in his paper on Charles Bonnet Syndrome in this issue, a form of illusion lies at the heart of vision itself. As with Bergson, this isn’t just about technology, or even scientific methods, but about the ways we think about reality, and maybe even something fundamental about how our brains work.

Mick Schofield, October 2020