Excellent Primer on unexplained aspects of vision - Gomez-Marin, Sheldrake

Did you read the paper?

Excellent question. I gave up when I came to this paragraph:

Yet, ironically, although students of biology and psychology are taught the intromission theory of vision, students of physics are still taught the extramission theory in optics. Modern physics textbooks present an account of mirror reflections in which virtual images are produced outside the eye (Figure 2), as in Euclid’s theory. The light rays are shown moving into the eye, but the visual rays that give rise to virtual images go in the opposite direction. This process is THE NATURE OF VISUAL PERCEPTION 5 described as follows in a typical British textbook for 14 to 16 year olds: “Rays from a point on the object are reflected at the mirror and appear to come from a point behind the mirror where the eye imagines the rays intersect when produced backwards” (Duncan and Kennett, 2001, p. 8). There is no discussion of how the eye “imagines” rays intersecting, or how it “produces” them backwards. Euclid’s diagrams showing the location of virtual images behind flat mirrors produced by the extramission of visual rays are essentially identical to those in modern textbooks (Takahashi, 1992).

The reason the extramission theory might still appear in physics textbooks, especially in the context of explaining phenomena like mirror reflections, is more about illustration convenience. It's easier to depict the path of light as extending from the eye to understand how mirrors create virtual images. This method is not meant to imply that eyes emit light rays; it's just a diagrammatic technique. (https://en.wikipedia.org/wiki/Emission_theory_(vision)

I think it's dishonest not to mention this.

I think it's dishonest not to mention this.

I thought the point was pretty clear that it's shown as a diagram but the "truth" is left unexplained, leaving open the question of what is really happening.

The paper's argument is about how the extended mind is assumed in varied contexts, but only allowed as a metaphor or convenient way of speaking due to certain prejudices related to materialist dogma...

Excellent question. I gave up when I came to this paragraph:


The reason the extramission theory might still appear in physics textbooks, especially in the context of explaining phenomena like mirror reflections, is more about illustration convenience. It's easier to depict the path of light as extending from the eye to understand how mirrors create virtual images. This method is not meant to imply that eyes emit light rays; it's just a diagrammatic technique. (https://en.wikipedia.org/wiki/Emission_theory_(vision)

I think it's dishonest not to mention this.

I agree, I momentarily balked when I read the 14-16y/o school textbook quote. I thought the authors were cherry picking, accurate, but rather weak evidence in support of their 'teaching' argument - to be provocative. However, there was a small part within that same textbook passage that I did find to be quite oddly worded "...where the eye imagines the rays intersect..."

You should try putting your valid objection to this argument aside, and continue reading the rest of the paper, because it's generally good.

I thought the point was pretty clear that it's shown as a diagram but the "truth" is left unexplained, leaving open the question of what is really happening.

The paper's argument is about how the extended mind is assumed in varied contexts, but only allowed as a metaphor or convenient way of speaking due to certain prejudices related to materialist dogma...

I agree that the textbook authors struggle to explain mirrors and vision, and that more generally, we have a huge problem explaining the overall context within which experience arises - and that science sidesteps this problem. However, I don't think there is any way that the quoted textbook passage supports the claim made in the authors paper, that 14-16 y/o students are being taught a theory of vision - where something is literally leaving people's eyes.

The authors suggest that the sense of being stared at is a clue that minds can interact...

Do minds have an ability to interact with anything outside the skull directly? The
phenomenon of scopaesthesia would suggest that they do

I think there may be better methods of testing this phenomena. Take the Blanke paper...

Blanke et. al. (2002) Stimulating illusory own-body perceptions
https://doi.org/10.1038/419269a

I’m speculating that Blanke’s report of induced ‘hallucinatory’ experiences, associated with electrical disruption of the patients neural network, might also be the result of anomalous transmission of information from the researchers undertaking the experiment.

Blanke et al say...

   

When asked to look at her outstretched
    arms during the electrical stimulation
    (n42; 4.5, 5.0 mA), the patient felt as
    though her left arm was shortened; the
    right arm was unaffected.

The researchers – presumably working on the right hand side of the patients head as mentioned in the paper...





2. would perceive the patients left arm (which is further away from them) as shorter than the right arm which is nearer to them....





3. The patients view of their arms should look something like this...





4. If the researchers perception of the patients arms, is anomalously transmitted to the patient, whilst the patient’s neural network is electrically disrupted. The shortened perception of the left arm might, become combined with the patients own perception, resulting in a hallucinatory perception within the patient that their left arm is shorter than their right.





I've spent years slowly becoming comfortable with this way of thinking about how our experience arises. It's difficult to get people thinking about how your sense of self would be perceived, if the sensory information (experience) you were perceiving as your own, was not only your own.

As Blanke’s patient is wakeful, when their neural network was destabilised. I’m speculating that anomalous local transmission of perceptual information from the researchers undertaking the experiment, can become combined with the patients own sensory perception, because the patients neural network is disrupted.

I spent a couple of days in London, to look through patient’s reports from Bethlem Hospital (Bedlam Mental Asylum). I certainly found cases that suggest a similar effect at work. For example: A mental patient who had quite normal body perceptions when isolated alone in a room. But when other people enter the same room, the patient perceives their own limbs as being located in different places around the room, and arm over there, a leg over here. It almost seemed as if this patient was anomalously combining sensory information from the people who had entered the room.

Blanke reports these other hallucinations which are harder to think about (we don't have any context about what the researcher is doing at that time), but there are hints...

   

Initial stimulations (n43; 2.0–3.0 mA)
    induced vestibular responses, in which the
    patient reported that she was “sinking into
    the bed” or “falling from a height”.

Can you imagine trying to unify your own visual experience (laid on a bed) with a third parties visual experience (the researcher) with who is standing above you whilst you lie on your back on a bed? (From the researchers visual perspective: what happens to the size of the patient when you go from a bent over head position to an unbent head position?)

Another quote from Blanke...

   

Increasing
    the current amplitude (3.5 mA) led to
    an OBE (“I see myself lying in bed, from
    above, but I only see my legs and lower
    trunk”). Two further stimulations induced
    the same sensation, which included an
    instantaneous feeling of “lightness” and
    “floating” about two metres above the bed,
    close to the ceiling

Can you imagine trying to unify your own visual experience with multiple third parties visual experience who are standing above you and around you, whilst you lie on your back on a bed?

Another quote from the paper...

   

When her eyes were shut,
    she felt that her upper body was moving
    towards her legs, which were stable (n42;
    4.0, 5.0 mA).

Can you imagine trying to unify your – eyes shut – proprioceptive experience of where your legs should be in relation to your head, with a third parties visual experience who is standing above you, whilst you lie on your back on a bed. (From the third parties visual perspective: They can see the patients legs?)

This experiment seems reproducible. What happens if the researcher/s all go and stand on the other side of the patient? Does the patients right arm get shorter, rather than their left arm?

How about using simple visual targets semi-hidden from the patient?

It seems difficult to get researchers to stop making assumptions about what's going on... and when they make assumptions... they close down the possibility of revealing the unexpected...

[Ninshub]

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Excellent Primer on unexplained aspects of vision authored by Alex Gomez-Marin & Rupert Sheldrake

https://www.sheldrake.org/files/pdfs/pap...eption.pdf

By the end of the paper, one realises these these unexplained visual issues can be extended into apparitions that are clearly from the past (Harry Martindale etc), and the typical hospital NDE Out-of-body experience.

Liked that the paper made a well presented argument and cited S. Lehar's paper on Gestalt Isomorphism.  Did not see the argument as grounded, without some reference to J.J. Gibson, a scientist who had decades of lab work behind his model of visional perception.

From the article:

 William James likewise rejected the idea of images or representations inside
the brain. He took as an example the reader sitting in a room, reading a book:
“[T]he whole philosophy of perception from Democritus’ time downwards has
been just one long wrangle over the paradox that what is evidently one reality 
should be in two places at once, both in outer space and in a person’s mind.

One reality being active in two (or more) parallel but corresponding environments - answers the question full stop.

For me this is obvious - there is the placement of physical signals in the environment of manifest physical events and another of bytes and logical structures in an environment of real-world probabilities (think Indra's net).  Extended mind is active in the later environment with structure and active mental output changing those probabilities actively.  Minds create information objects that can restructure ambient real-world probabilities.  Such as, making a decision to get-up to make tea or spend 20-25 years in school to be a PhD.

Liked that the paper made a well presented argument and cited S. Lehar's paper on Gestalt Isomorphism.  Did not see the argument as grounded, without some reference to J.J. Gibson, a scientist who had decades of lab work behind his model of visional perception.

From the article:

One reality being active in two (or more) parallel but corresponding environments - answers the question full stop.

For me this is obvious - there is the placement of physical signals in the environment of manifest physical events and another of bytes and logical structures in an environment of real-world probabilities (think Indra's net).  Extended mind is active in the later environment with structure and active mental output changing those probabilities actively.  Minds create information objects that can restructure ambient real-world probabilities.  Such as, making a decision to get-up to make tea or spend 20-25 years in school to be a PhD.

We do appear to sum the system state to a result (our experience). And this has to happen in a way that transcends spacetime, this is to allow the summing to occur across all matching patterns, no matter where or when they occurred. Everything still pretty much turns out according to our classical understanding - except that understanding is all wrong. Those occasional niggly subjective experiences - which turn out not to be ours, are the clues which give the game away. I don't really see them as probabilistic calculations any more, the randomness isn't really random, it's dynamic, and there is just too much of it to make any sense of, other than through experience itself.

We do appear to sum the system state to a result (our experience). And this has to happen in a way that transcends spacetime, this is to allow the summing to occur across all matching patterns, no matter where or when they occurred..... the randomness isn't really random, it's dynamic, and there is just too much of it to make any sense of, other than through experience itself.

well ---  that's a "hell, yes" for me.  Summing the system state is not a probing of reality, as a physical entity.  It is a probing of reality that hopes for discoverable informational entities.  The feedback in the results from such a probing, "work" logically!   That, to me at least, is direct evidence that there is process "depth" to the environment containing informational interactions.

(The Vienna folks have published on the extant natural connection of logic and quantum operations.) 

Your words struck me. "No matter where or when".  Manifest physical reality nests in time and space.

On the other hand, the environment of information activity exists backward and forward in time and by its nature presents outside of space. Science methods find information as detectable pasts and futures.  Further, information science details the structures that exist, coherently.   Structured information is useful outside of time and in spaces that existed in the past and in probable future states.

When you speak of dynamics in the realm of the possible, I think of the well-worn idiom, "an idea whose time has come".  I would see a way which takes that literally, with measurements and observations from the informational environment.  Heck, political polls are just an example of data gathering that enables an application of "whose time has come" projection of actual outcomes.