The choice of measurement instead allows information to be decoded from the observed pattern, i.e., information revealing interference, or not.
— Andrew M

I'm trying to unpack this statement. Could this be related to the Wikipedia entry where it says that "a photon in flight is interpreted as...something that has the potentiality to manifest as a particle or wave, but during its time in flight is neither." So upon flight the photon has a potential state but upon 'decoding' we deduce a history to say that it held an actual state (of a particle or a wave)? If so, the deduction of history follows the measurement, which is what I'm positing.

I don't think my current understanding assumes retrocausality since I'm not claiming that any information is being sent back in time. — keystone

Fair enough. The important (non-spooky) point with the delayed-choice quantum eraser experiment is that the original observed pattern for the signal photon (upper red and blue paths in Figure 2) is the same, regardless of what happens later to the entangled idler photon (lower red and blue paths) with beam splitters and what not. Which is to say, one's delayed choice has no effect on that signal photon pattern, and nothing is ever erased in that signal photon pattern. Instead, if the which-way information for the idler photon is erased then you can use the later detector recordings to reveal two phase-shifted interference patterns in the signal photon pattern, per Figure 5 (i.e., R01 and R02).

So it's different to the double-slit experiment where the choice to detect the photons, or not, at the slits does affect what is later observed on the back screen.

I'm not sure anything can be deduced about the history of the photon in either experiment since one's assumptions will be interpretation-dependent.

Maybe try RQM instead.
— noAxioms

From my amateur position, the idea of there being no objective collapse doesn't sit well with me. I'll keep this in mind but right now I'm still grappling with vanilla QM. — keystone

Interestingly, that would be a different physical theory which can be potentially tested. That's given rise to the Wigner's Friend-style thought experiments over the past few years.

4 Wigner-Deutsch thought experiment

Two central questions that came up repeatedly in our discussions so far are (i) “Does Alice see a definitive measurement outcome?” and (ii) “Is Alice’s lab after the measurement indeed in a superposition state?” Deutsch [23] proposed an extension of the thought experiment described in Section 3, which turns these questions into (in principle) experimentally testable statements. — Testing quantum theory with thought experiments, p17 - Nurgalieva, Renner

Measurement doesn't affect anything in the past.
— Andrew M
It does in some counterfactual interpretations like Bohmian mechanics. That's a pretty major interpretation. — noAxioms

I don't think that's the case. From SEP (though note they do discuss a retrocausal variant there):

Foundational accounts which like Bohmian mechanics (Bohm 1952a,b) or GRW-theory (Ghirardi, Rimini, & Weber 1986) avoid postulating retrocausality do so by violating time-symmetry in some way. The GRW-theory does so by introducing explicitly time-asymmetric dynamics. In Bohmian mechanics the dynamics is time-symmetric, but the theory is applied in a time-asymmetric manner when assessing which quantum states are actually realized. — Retrocausality in Quantum Mechanics - SEP

In learning about QM and amazing experiments like the delayed-choice quantum eraser experiment, I have come to think that in a way the quantum measurement precedes the history. — keystone

Measurement doesn't affect anything in the past. In the delayed-choice quantum eraser experiment, the original observed pattern remains the same regardless of the later choice of measurement.

The choice of measurement instead allows information to be decoded from the observed pattern, i.e., information revealing interference, or not.

That's the consensus amongst physicists. None of the major interpretations posit retrocausality.

However, the interference pattern can only be seen retroactively once the idler photons have been detected and the experimenter has had information about them available, with the interference pattern being seen when the experimenter looks at particular subsets of signal photons that were matched with idlers that went to particular detectors. — Delayed-choice quantum eraser: Consensus: no retrocausality - Wikipedia

Then again, physicists and the rest of us can count on both realism and locality in the world where we live our lives. I'm not saying the results of quantum mechanics aren't important, but they are scale-dependent. Here at human scale, we can live our lives as we always have. — Clarky

Yes, for macroscopic systems at low velocities in weak gravitational fields, QM and relativity approximate classical Newtonian mechanics (as an emergent classical limit).

Incidentally, I've been reading an article on QBism. As far as I understand it, it makes sense to me.

Schrödinger thought that the Greeks had a kind of hold over us — they saw that the only way to make progress in thinking about the world was to talk about it without the “knowing subject” in it. QBism goes against that strain by saying that quantum mechanics is not about how the world is without us; instead it’s precisely about us in the world. The subject matter of the theory is not the world or us but us-within-the-world, the interface between the two.
— Chris Fuchs

That really nails it for me, because, if you think about it, it actually lines up with Kant. — Wayfarer

:up: As Fuchs implies with "us-within-the-world", there's no view from nowhere.

But logically, as the superposition refers to all of the elements in an entangled system, then to measure the one is to measure the other. — Wayfarer

Just to be precise here, measurement involves an interaction between a measurer and what is being measured. That Alice measures her entangled particle doesn't imply that a measurement has been made or ever will be made on Bob's entangled particle. Instead, if both Alice and Bob do measure their particles and later meet up to compare notes, then they will find that their measurements are correlated per the predictions of quantum theory. That is, Alice needs to not just perform her local experiment, she also needs to locally interact with Bob and his measurement.

Thanks again. — Clarky

:up:

What does 'locally realistic' mean? It doesn't make a lot of sense as plain English. — Wayfarer

Below is the broader quote that that phrase was taken from, describing Bell's Theorem. Both locality and realism are technical terms. Don't equate the latter with philosophical or scientific realism. In the sense used here, realism is the assumption that a superposition has a well-defined value independent of measurement (also termed counterfactual definiteness). So, for example, that a particle described by a superposition as being "here + there" really is just here or there independent of measurement, we just don't know which it is.

There are two assumptions made in the proof of (2.225) which are questionable:

(1) The assumption that the physical properties PQ, PR, PS, PT have definite values Q, R, S, T which exist independent of observation. This is sometimes known as the assumption of realism.
(2) The assumption that Alice performing her measurement does not influence the result of Bob’s measurement. This is sometimes known as the assumption of locality.

These two assumptions together are known as the assumptions of local realism. They are certainly intuitively plausible assumptions about how the world works, and they fit our everyday experience. Yet the Bell inequalities show that at least one of these assumptions is not correct.

What can we learn from Bell’s inequality? For physicists, the most important lesson is that their deeply held commonsense intuitions about how the world works are wrong. The world is not locally realistic. Most physicists take the point of view that it is the assumption of realism which needs to be dropped from our worldview in quantum mechanics, although others have argued that the assumption of locality should be dropped instead. Regardless, Bell’s inequality together with substantial experimental evidence now points to the conclusion that either or both of locality and realism must be dropped from our view of the world if we are to develop a good intuitive understanding of quantum mechanics. — Quantum Computation and Quantum Information - Nielsen and Chuang

Both of those links are really helpful. Thanks. — Clarky

:up:

Here's some more from Peres that argues for the locality point-of-view.

Bell’s theorem (1964) asserts that it is impossible to mimic quantum theory by introducing a set of objective local “hidden” variables. It follows that any classical imitation of quantum mechanics is necessarily nonlocal. However Bell’s theorem does not imply the existence of any nonlocality in quantum theory itself. In particular relativistic quantum field theory is manifestly local. The simple and obvious fact is that information has to be carried by material objects, quantized or not. Therefore quantum measurements do not allow any information to be transmitted faster than the characteristic velocity that appears in the Green’s functions of the particles emitted in the experiment. In a Lorentz invariant theory, this limit is the velocity of light.

In summary, relativistic causality cannot be violated by quantum measurements. The only physical assumption that is needed to prove this assertion is that Lorentz transformations of the spacetime coordinates are implemented in quantum theory by unitary transformations of the various operators. This is the same as saying that the Lorentz group is a valid symmetry of the physical system (Weinberg, 1995). — Quantum Information and Relativity Theory - Asher Peres, Daniel R. Terno, 2003

Choose between what principles?
— Wayfarer

The video you provided talked about the violation of realism versus the violation of locality. According to the narrator, if realism is violated, but locality isn't, there is no superluminal causality or communication. — Clarky

Spot on. As it happens, most physicists choose locality over realism [*]. This rejection of realism (precisely, counterfactual definiteness) is well summed up by physicist Asher Peres, one of the original developers of quantum teleportation, as "unperformed experiments have no results".

--

[*] "What can we learn from Bell’s inequality? For physicists, the most important lesson is that their deeply held commonsense intuitions about how the world works are wrong. The world is not locally realistic. Most physicists take the point of view that it is the assumption of realism which needs to be dropped from our worldview in quantum mechanics, although others have argued that the assumption of locality should be dropped instead." - Quantum Computation and Quantum Information - Nielsen and Chuang

As the valves became tiny transistors, a decimal system would require 30 transistors to represent the range 0..999 but can such a problem not be overcome using something like floating-point representation? — universeness

A representation that was later used was binary-coded decimal. That required four transistors per digit, for a total of twelve transistors for a 3-digit decimal.

Yes, but it not stays in that state, and two states are necessary for quantum computing. There was a computing done in which about 70 (I don't remember the exact number) qubits were involved, facilitating 2exp70 possibilities in parallel. — Cornwell1

Yes, and I see now that you're referring to qubit coherence. I found an interesting summary of the historical and projected improvements in coherence times for quantum computing systems:

In the graph below are coherence times for notable studies of the last 20 years, the most recent being a time of 22 milliseconds. A future trend line is also projected to 2040. Based on this rate of progress, it appears feasible that a quantum computer will achieve coherence of one second or more before the end of this decade. Assuming that trend continues, we could see 10, 100, or even 1,000 seconds during the 2030s. A major milestone will be the cracking of RSA-2048 encryption keys (among the world's most secure algorithms), which a quantum computer with 4,100 stable qubits could achieve in 10 seconds. That same task would take a classical computer around 300 trillion years. — Quantum coherence times, 2000-2040

After a measurement the state tends to evolve to a state with both up and down equally present. — Cornwell1

After measurement, the spin state will be definitely up or down, and not in superposition.

There are only 2 states involved in the computing. — Cornwell1

The point of quantum computing is that computation can be done on superposition states. It's just the final measurement that reduces (collapses) to one of the two basis states (0 or 1).

There potentially infinite states, that's true, but you make it sound if this infinity is part of the computing power. — Cornwell1

That wasn't the point of my comment but, sure, I think it's a part of it. Consider modelling nature - the more available states, the more accurately and precisely it can be modelled.

You need 30 tubes for all decimals 1-999 though and only 10 for the binary version. Is that last to which you refer? — Cornwell1

Yes - see the ENIAC example link in my initial post (which showed 30 tubes).

but a potentially infinite number of superposition states
— Andrew M

Isn't the number of superimposed states 2^n, where n is the number of electrons entangled? — Cornwell1

I'm referring to the different states that a single qubit can be in. Every point on the surface of the Bloch sphere (where the sphere represents a qubit) is a potential pure state.

999 could be stored using 3 of the 'state 9' tubes. — universeness

Yes, but there are 30 tubes in total, compared to 10 tubes for binary. See the ENIAC example link in my initial post.

I remember reading quite some years ago that a 'musical christmas card' - the type that plays a tinny carol when you open it - contains more computing processing power than existed in the world in 1946. — Wayfarer

Reminds me of Marvin, the android from Hitchhiker's Guide to the Galaxy. A brain the size of a planet, and they used him to open doors...

That top reference hits the nail right on the head. — Wayfarer

:up:

'The ENIAC required 30 vacuum tubes to store the decimal 128. Ten for the 1, ten for the 2 and ten for the 8. In addition, it had to turn on 11 tubes.'

No wonder it was so enormous! :yikes: — Wayfarer

Numbers can be stored in a binary representation about 3 times more efficiently than in a decimal representation (since 2^3 is approximately 10), so 999 (1111100111 in binary) would require 10 vacuum tubes. The miniaturization improvements are really to do with the hardware, e.g., billions of transistors on a chip compared to the space required for vacuum tubes.

they just use Qbits which have three states instead of two (the third state is based on quantum entanglement, so the system is still basically binary). — universeness

A qubit has two measurable states (0 and 1), but a potentially infinite number of superposition states. Entanglement is a different phenomenon and requires two or more qubits.

Anyway, never mind, my question is, did the earlier computers, such as ENIAC, not operate on binary digits? Shannon's paper was published in 1948 and ENIAC commenced operations in 1945. My knowledge of maths and computer science is rudimentary but I'm finding it hard to imagine how computers could operate on anything other than binary digits — Wayfarer

Earlier computers represented numbers in decimal. Here's an example. So, consider adding 4 to 128. 8 + 4 modulo 10 = 2. So only the bottom two vacuum tubes would be switched on in the third column. 8 + 4 > 10, so carry 1 to the second column. 2 + 1 modulo 10 = 3. So only the bottom three vacuum tubes would be switched on in the second column.

(leaving aside quantum computers, which I know I'll never fathom). — Wayfarer

Quantum computers use qubits which are able to represent bit values (0 and 1) in superposition.

No excuses. — Mww

No problem. :up:

First were these two.....

This is just another way of saying that to perceive a red flower in a vase entails that there is a red flower in a vase (i.e., the logic of perception).
— Andrew M

We're investigating what we perceive (i.e., can point at), and what we perceive is the object "as it is in itself", so to speak.
— Andrew M

....later was this.....

my position is that of Indirect Realism (...) rather than Direct Realism (our senses provide us with direct awareness of the external world, and the world derived from our sense perception should be taken at face value).
— RussellA

...which confuses me, because in our dialogue it seemed as if your position was just what you claimed it was not. Seems to me as if the first two statements support the direct realist doctrine. — Mww

I'm not sure whether your comment was intended for RussellA or myself. But my position is neither direct (naïve) or indirect realism - I reject the antithesis [*]. See my earlier post here.

I also reject the Kantian appearance/thing-in-itself distinction, which is what my second comment above was meant to convey.

Both are artificial philosophical distinctions, not natural distinctions, such as that between a tree and an image of a tree (e.g., a photograph).

--

[*]

I am not, then - and this is a point to be clear about from the beginning - going to maintain that we ought to be 'realist', to embrace, that is, the doctrine that we do perceive material things (or objects). This doctrine would be no less scholastic and erroneous than its antithesis. The question, do we perceive material things or sense-data, no doubt looks very simple - too simple - but is entirely misleading (cp. 'Thales' similarly vast and over-simple question, what the world is made of). One of the most important points to grasp is that these two terms, 'sense-data' and 'material things', live by taking in each other's washing - what is spurious is not one term of the pair, but the antithesis itself. — Sense and Sensibilia - J.L. Austin

So saying, your system only works for extant knowledge, but is hopelessly futile for that of which we have no experience. Yet, there are multiple instances of perceiving information to which we can relate no object at all. — Mww

My view is that knowledge comes from experience. What instances did you have in mind?

One must already have the experience of red flowers in vases, before he can say an instance of perception, is that. — Mww

Indeed. A nice point of agreement to end with!

It's really not. It's a well-established issue. It's a matter of empirical fact that the brain - for that matter, the entire human organism - comprises thousands of semi-autonomous sub-systems, all of which are subsidiary to the unified experience of being. You can't simply philosophise it out of existence. — Wayfarer

Well-established or not, the 'binding problem' has dualist premises (as with the 'hard problem of consciousness'). It's not just me pointing it out. See Bennett and Hacker:

For the neural correlates, the various cells firing in the various locations of the 'visual' striate cortex, cannot be 'recombined', and do not need to be. The thought that the features a perceiver perceives must be correctly synthesized 'to form a separate object', the so-called 'binding problem', is confused. (For critical discussion see pp. 32-8.) To perceive is not to form an image of what is perceived, either in one's brain or in one's mind. What is perceived is the tree in the quad, not a representation of a tree in the quad. The brain does not have to synthesize a representation of the tree out of representations of its size, shape, colour and orientation - it has to enable the perceiver to see the tree and its features clearly. — History of Cognitive Neuroscience, p55 - Bennett, M. R., Hacker, P. M. S.

Also Dennett:

[There is no single, definitive "stream of consciousness," because there is no central Headquarters, no Cartesian Theater where "it all comes together" for the perusal of a Central Meaner....]

While everyone agrees that there is no such single point in the brain, reminiscent of Descartes's pineal gland, the implications of this have not been recognized, and are occasionally egregiously overlooked. For instance, incautious formulations of "the binding problem" in current neuroscientific research often presuppose that there must be some single representational space in the brain (smaller than the whole brain) where the results of all the various discriminations are put into registration with each other — marrying the sound track to the film, coloring in the shapes, filling in the blank parts. There are some careful formulations of the binding problem(s) that avoid this error, but the niceties often get overlooked. — Consciousness Explained, p257 - Daniel Dennett

I've been studying hylomorphism, and it's called a dualism. Why? Because it comprises two separate aspects of the intelligence - the sensory and the intelligible. According to Aristotelian dualism, the senses perceive the sensable form of the object, but the intellect perceives it's nature or essence. — Wayfarer

Aristotle's hylomorphism is not dualist. See our previous discussion on this.

According to Aristotle, both humans and lower animals perceive things, but humans have the further ability to abstract and reason about those things (hence the rational animal). That's an identification of a living being's capabilities, not an expression of dualism. Also your phrasing above is what Bennett and Hacker term the "mereological fallacy":

A form of this error was pointed out around 350 BC by Aristotle, who remarked that "to say that the soul [psuche] is angry is as if one were to say that the soul weaves or builds. For it is surely better not to say that the soul pities, learns or thinks, but that a man does these with his soul" (De Anima 408 12-15) - doing something with one's soul being like doing something with one's talents. It is mistaken to ascribe to the soul of an animal attributes that are properly ascribable only to the animal as a whole. We might call this "Aristotle's principle". — Neuroscience and Philosophy: Brain, Mind, and Language, pp131-2 - Bennett and Hacker

We're investigating what we perceive (i.e., can point at), and what we perceive is the object "as it is in itself", so to speak.
— Andrew M

This is what I'm saying is naive realism - the contention that we perceive objects as they are 'in themselves'. The distinction I'm making is not a distinction between seeing an image, and seeing a real thing. What I'm pointing out is that when you say that 'you see the tree as it is in itself' then you're speaking from a naive realist point of view. — Wayfarer

However it is the distinction I am making. I reject that we see only images (of unknown things), hence the allusion to Kant:

And we indeed, rightly considering objects of sense as mere appearances, confess thereby that they are based upon a thing in itself, though we know not this thing as it is in itself, but only know its appearances, viz., the way in which our senses are affected by this unknown something. — Prolegomena, § 32

What can’t be accounted for is the neural system that unifies them. So you’re actually begging the question, you’re assuming the very point at issue. — Wayfarer

Well, you're assuming there is a 'binding problem' to be solved, but this is an artefact of a representationalist scheme. See the photograph example below and also my last comment in this post to Mww.

That is naive realism, is it not? Doesn’t that simply bypass the requirement for critical reflection on the nature of experience? — Wayfarer

It's not naïve realism, which I think functions as one side of an artificial antithesis. The critical reflection is about whether what we are perceiving in a given instance is a representation of something else, or not.

Sometimes it is, such as when we see a portrait or a photograph. We can refer to a tree image in a photograph (e.g., the tree looks glossy) or the tree that the image is of (e.g., I used to climb that tree as a kid).

At other times it isn't, such as when we see a tree in the garden. So it's a natural distinction as opposed to an artificial antithesis where everything we perceive is representation, or nothing is.

‘The sunset’ signifies a particular time of day, saying it I can quite easily mentally picture a sunset. I don’t think that is problematical. — Wayfarer

Agreed. In this case, you're not perceiving a mental picture (cue the Cartesian theater), you're imagining a sunset. And that, in turn, is a different activity to perceiving a sunset.

--

Yet you’ve preface every one of those examples with “I”, the feeling of excitement, fond memory of the restaurant, more knowledge on the job. All of those belong to you alone, you said it yourself. So how can any of them be in the world if they are in you. If you’re right, I should go to that restaurant and experience your fondness for it. But it happened to be Thai and I hate Thai. — Mww

No accounting for taste I guess! Regardless, there are plenty of people out there who do share my fondness for Thai (and some that share your aversion).

When we both experience clouds, but I imagine a lion and you imagine a seagull in the same cloud formation......how do you explain those different experiences given from the exact same object? — Mww

Presumably if I looked just where you looked, I could pick out a lion shape too. If not, I'm sure there's a perfectly natural reason why not. Maybe you've just got a more vivid imagination than me.

But, yes, we are different people so we won't necessarily have the same experiences.

Even if he passes on mere information, doesn’t that still represent the perception? Otherwise he must pass on the red itself flower itself in itself a vase itself, which is quite absurd. — Mww

The red flower itself is not passed on, only information. That information allows us to perceive the object (in the world) in a particular form. That use of information and form can be compared to Aristotle's hylomorphism where the form is in the object, so to speak, which is why the object is perceptible.

This is just another way of saying that to perceive a red flower in a vase entails that there is a red flower in a vase (i.e., the logic of perception). So when we perceive the red flower, we're not perceiving a representation of the red flower (like a photograph), we're perceiving the object itself.

Thus there is no 'binding problem' that is not simply the problem of why things in the world (including the perceiving creatures themselves) have the relationships and character that they do.

Hmmmm. “In the world” implies spatial location, and because experience is not in the world, I would go with “grounded by the world”. This removes the ambiguity of location ... — Mww

That doesn't seem right to me. I experienced the excitement of New York in New York. I had a memorable experience at the restaurant. I gained experience in my job at the supermarket. Getting stung by a wasp in the garden was a painful experience.

Are you using the term "experience" differently to all of those?

Ever wonder how it became “red flower in a vase”? How does something....anything.....get its characteristics? — Mww

Yes. Why is the sky blue? Why does the glass window have no color? We seek to understand by investigating the things we observe (which can also include the creatures doing the observing).

I can also think about the conceptual schemes within which those questions can be posed.

No, we have thoughts and feelings about representations of perceived objects in the world. It behooves the purely physicalist-minded, to remember 100% efficiency of energy transformation is absolutely impossible for human sensory apparatus. Because there is necessarily energy loss, that which is upstream from sensation can never be the same as what is downstream from it. If the latter is different in some way, it can no more than merely represent the former to some arbitrary degree.

That relieves us of invoking the tautological nonsense of saying things like, “there are no basketballs, ‘57 DeSoto’s.....and no “red flowers in a vase”.....in my head”. — Mww

But that assumes the process involves making "copies" of the objects (however imperfectly), as opposed to providing information about them. On a non-representationalist view, no copy is being made. Instead we are perceiving the original object (e.g., clearly in well-lit conditions, or unclearly if there's a fog about).

This is a conceptual, not an empirical point. We're investigating what we perceive (i.e., can point at), and what we perceive is the object "as it is in itself", so to speak. It's not a representation of some further removed imperceptible and indeterminate object.

All that reduces to.....is it a red flower in a vase because it just is that, or, is it a red flower in a vase because we say it is just that. Personal preference? — Mww

Yes we have a say in what conceptual scheme we use. On a non-representationalist model, objects have natural characteristics that we can discover. Within that model, depending on the environmental conditions, we can be correct or mistaken about what those objects and characteristics are.

This is not dependent on representative realism. — Wayfarer

It's dependent on a representationalist conceptual scheme, for reasons I've given (I haven't been using the word "realism", which brings its own baggage to these discussions). But I'm curious whether you would agree with Mww's comment here:

No, we have thoughts and feelings about representations of perceived objects in the world. — Mww

This elaboration in effect twice removed qualia from Kantian metaphysics, — Mww

:up:

insofar as all experience has phenomenal ground, hence the notion of “superfluous”, and, experience doesn't even have “character” in the Enlightenment transcendental sense — Mww

So I'm curious whether you think that statement is compatible with the view that experience is grounded in the world, understood as that which we can point to around us (and which do have characteristics, e.g., the red flower in the vase).

while experience is certainly predicated on sense data given from objects of perception, feelings just as certainly are not. — Mww

And also whether that statement is compatible with saying that what we perceive are objects in the world (which we have attendant thoughts and feelings about).

(I note that you mention "sense data", but also that it is not "sense data" that is perceived, since it is not an object of perception).

One can hold with such representational model, while abstaining from incorporating qualia in it. — Mww

Thanks, I think I'm clearer on your view now. I might come back to this later.

But even in the non-representationalist view we don't perceive a tree (an external object) directly but only as "marks" left by incoming photons in our nervous system and these "marks" are a representation of the tree, not the tree itself, so I don't understand why such a view would be called non-representationalist. — litewave

Because we're not perceiving either a neural or a mental representation of the tree, we're perceiving the tree itself. Further, the 'binding problem' assumes there must be a unified representation or image, which the non-representationalist view rejects.

When an OCR machine recognizes an alphabet character or a self-driving vehicle recognizes a pedestrian crossing the street, does it do so via a representationalist method or a non-representationalist method? — litewave

Non-representationalist for the self-driving vehicle - it's recognizing objects in the environment, not "perceiving" an image. Could go either way for the OCR machine, i.e., whether one would say it's recognizing the alphabetic character on the paper, or on the captured image.

So I'm puzzled by statements like this:

"One cannot combine colour, form and dimensions into perceptions, just as one cannot put events into holes (sic) - this form of words makes no sense." — History of Cognitive Neuroscience, pp37-38,55 - Bennett, M. R., Hacker, P. M. S. — Wayfarer

Maybe because you conceive of perception differently to B&H (and, I might suggest, ordinary language users). Color, form and dimensions are characteristics that objects have. Perception is the process by which we become aware of an object with such characteristics. It's not a process of purple, squareness and boxhood being synthesized in our minds or, alternatively, brains.

BTW, I'm not sure why you added "(sic)" to the quote. B&H were pointing out that it's a category mistake.

I'm not going to press the point, as I really don't have a lot of interest in deliving into all of the literature about a very complex problem in cognitive science. Suffice to say though I'm not at all persuaded by their dismissal of it, and nothing you've said conveys any sense that you've really gotten the point of the argument. It has nothing directly to do with 'qualia'. — Wayfarer

Qualia is central to the argument in the paper you originally quoted:

The subjective unity of perception

We will now address the deepest and most interesting variant of the NBP, the phenomenal unity of perception. There are intractable problems in all branches of science; for Neuroscience a major one is the mystery of subjective personal experience. This is one instance of the famous mind–body problem (Chalmers 1996) concerning the relation of our subjective experience (aka qualia) to neural function. Different visual features (color, size, shape, motion, etc.) are computed by largely distinct neural circuits, but we experience an integrated whole." — The neural binding problem(s) - Jerome Feldman

I can assure you that I don’t. I just don’t think Hacker and Bennett can explain away the issues of the neural binding problem with a brief bit of philosophical jargon. — Wayfarer

They wrote the influential book "Philosophical Foundations of Neuroscience" so they've given these issues serious consideration. To make an analogy to another scientific field, perceived problems for some quantum interpretations (say, non-locality, or many worlds) do not necessarily arise for others. The conceptual model makes a difference.

I mentioned Andrew Brook above, a scholar who says that Kant is ‘the godfather of cognitive science’. I wonder what H&B would make of that? — Wayfarer

I don't know. They don't mention Kant in PFN.

//ps// Is Bennett a neuroscientist or a cognitive scientist? — Wayfarer

Emeritus Professor of Neuroscience and University Chair at the University of Sydney.

It is simply indubitale that subjective experience is in part constituted by sensory data, I can't see how that can plausibly be denied. — Wayfarer

Maybe that's because you think in representationalist terms. ;-)

When we watch the sunset we're aware of the colours, the sounds, the wildlife, the trees, the clouds in the sky, our feelings, the thoughts in our mind, all as elements of a subjective whole, of watching the sunset. It's indubitable that I am a subject of that experience and that the experience is unified; I don't receive signals from my sensory organs in the third person and then work on integrating them. I see, hear, smell, feel, and reflect. The mind is integrating the data into a sense of aesthetic appreciation. — Wayfarer

As I see it, the issue is a difference of conceptual models.

On a representationalist view, there is a separation of (subjective) experience from the (objective) world. The subjective experience has to be synthesized from the signals coming from the environment. Hence the binding problem.

Whereas on a non-representationalist view, what we perceive just is the world (which we have attendant thoughts and feelings about). The signals coming from the environment enable us to perceive what is there.

To fill that out a bit, consider the following mathematical function that has a fixed-point:

$f(x) = x^2 - 2$

The number $2$ is a fixed point of function $f$ because $f(2) = 2$. That is, the output of the function in that case just is the input.

Note that what is output is not a representation or synthesis of the input (or its properties). It's just the input itself (despite the function applying transformations to that input).

A human being in a normally-lit environment can be analogized to that function. There's a tree in its environment (the input), then a causal process occurs (the function) culminating in one's perception of the tree in its environment (the output). It's the same tree - the output just is the input (with the additional effect that the person is now aware of it).

Why is it the same tree? Because that's how we've set up the language game (or conceptual model). We point at a tree and define that as the input to the function - that's what we mean when we say "tree". When we get the same thing out that we put in, then we say that we have seen a tree. Whereas if we find out that we got something different, we use different language to describe the situation (e.g., "No, I didn't see a tree, it was a rock that just looked like a tree from that location.").

Scientists can investigate the causal process to understand how it works. Analogous to a mathematician investigating a function to understand how it works. But, under the non-representationalist model, science can't show us that what we see is different to what is there any more than mathematics can show us that $2^2 - 2 \neq 2$.

The benefit of the non-representationalist model is that we get to identify things in the world with what we perceive. And so a binding problem doesn't arise under that model. If what is there is a unity (e.g., B&H's example of a 'square purple box'), then so is what is perceived, since they're just the same thing.

I only used the compounded terminology because that was how it was originally presented. All experience is subjective, in that any experience belongs only to the rational agent that reasons to it, therefore “subjective experience” is superfluous.

I reject the concept of “qualia” outright, as superfluous as well, insofar as the given senses of them are already accounted for in established metaphysics. That is not to say they are false, or don’t have their own predication, but only that such predication has earlier, and better, representation. — Mww

Thanks! You omit those words (as superfluous) but, as I understand it, retain the underlying representationalist model.

why would a "neural representation" be assumed in the first place?
— Andrew M

Because this: representation is necessarily the case, and because neurons are the only possible source of representations as such, therefore neural representations. — Mww

You say it as if you believe it. But if the conclusion fails empirically (as Feldman's paper claims), then that raises questions about the premises.

Cartesian theater was never the case, and subjective experience has long evolved from Descartes, as ↪Wayfarer so aptly noted. — Mww

Could you expand on what you mean by "subjective experience"? I'm primarily addressing the paper that Wayfarer quoted where that phrase was used (and which was specifically equated with "qualia").

I'm sceptical about their dismissive attitude, as I think that the subjective unity of experience is an elemental constituent of self-knowledge; our experience, our being, functions as a unified whole. But the Feldman paper says 'There is now overwhelming biological and behavioral evidence that the brain contains no stable, high-resolution, full field representation of a visual scene, even though that is what we subjectively experience (Martinez-Conde et al. 2008). The structure of the primate visual system has been mapped in detail (Kaas and Collins 2003) and there is no area that could encode this detailed information. The subjective experience is thus inconsistent with the neural circuitry.' — Wayfarer

I'm not sure you're fully understanding B&H's position. Feldman is saying that we "subjectively experience" a "full field representation of a visual scene" (which doesn't seem to be in evidence, hence the 'binding problem'). Whereas B&H's position is that we experience the world (say, watching a sunset). The inclusion of "subjectively" and "representation" just is the homunculus looking at a theater screen. Remove those terms (and the conceptual scheme they represent) and no binding problem arises, since there's nothing to bind or synthesize. There's no binding of a sunset, it's already of one piece, so to speak.[*]

In other words, there is no "subjective unity of experience" because there is no "subjective experience (aka qualia)". There's just the garden-variety experiences of watching a sunset, or kicking a football around with your kids. As Bennett and Hacker say:

The brain does not have to synthesize a representation of the tree out of representations of its size, shape, colour and orientation - it has to enable the perceiver to see the tree and its features clearly. — History of Cognitive Neuroscience, pp37-38,55 - Bennett, M. R., Hacker, P. M. S.

--

[*] What we might do is reflect on our experiences and use language to talk about them which, of course, is representational.

It's not the creation of an image per se but the ability to recognise the concrete whole and to recognise it and interpret it. — Wayfarer

Yes, that's the real issue. As B&H say:

Which neuronal groups must simultaneously be active in order to achieve optimal vision, what form that activity may take, and how it is connected with other parts of the brain that are causally implicated in cognition, recognition and action, as well as in co-ordination of sight and movement, are what needs to be investigated by neuroscientists.
— History of Cognitive Neuroscience, pp37-38,55 - Bennett, M. R., Hacker, P. M. S.

That doesn't really contradict the passage I quoted, as far as I can see. — Wayfarer

The above B&H quote doesn't assume a binding problem. From the passage you quoted (italics mine):

That is, enough is known about the structure and function of the visual system to rule out any detailed neural representation that embodies the subjective experience. — The neural binding problem(s) - Jerome Feldman

The issue, as B&H argue, is that the "neural representation" assumption is mistaken, thus there is no binding problem to explain. But why would a "neural representation" be assumed in the first place? Because "subjective experience" (defined in the paper as "qualia") is a Cartesian conception of experience (the Cartesian theater, as it were).

There is one interesting and scientifically-validated piece of evidence for the immaterial nature of mind. This comes from a discussion of the 'neural binding problem' in neuroscience. 'Binding' is the cognitive process which brings together all of the various elements of perception - movement, shape, colour, position, the nature of the object, and so on - into the unified whole that comprises subjective experience (called the 'stable world illusion'). In brief, the neural binding problem is that neuroscience can find no functional area of the brain which can account for this unified sense of self. — Wayfarer

The 'binding problem' assumes there's a representation or image that needs 'binding'. But that's not the case, as Bennett and Hacker explain:

1.9.1 Misconceptions concerning the existence of a binding problem

The sense in which separate neural pathways carry information about colour, shape, movement, etc. is not semantic, but, at best, information-theoretic. In neither sense of 'information' can information be 'organized' into 'cohesive perceptions'. In the semantic sense, information is a set of true propositions, and true propositions cannot be organized into perception (i.e. into a person's perceiving something). In the engineering sense, 'information' is a measure of the freedom of choice in the transmission of a signal, and the amount of information is measured by the logarithm to the base 2 of the number of available choices - and this too is not something that can be 'organized' into perceptions. One cannot combine colour, form and dimensions into perceptions, just as one cannot put events into holes - this form of words makes no sense. And, correspondingly, when we see a square purple box, we do not 'combine' purple, squareness and boxhood - for this too is a nonsensical form of words. It is true that in order to see a coloured moving object with a given shape, separate groups of neurons must be active simultaneously. But it does not follow that, in the semantic sense of information, the brain must 'associate' various bits of information; nor could it follow, since brains cannot act on the basis of information or associate pieces of information. Whether the brain, in some sense that needs to be clarified, 'associates' information in the information-theoretic sense is a further question. But if it does, that is not because the features of the object perceived have to be 'combined in the brain', for that is a nonsense.

Above all, to see an object is neither to see nor to construct an image of an object. The reason why the several neuronal groups must fire simultaneously when a person sees a coloured three-dimensional object is not because the brain has to build up a visual image or create an internal picture of objects in the visual field. When we see a tree, the brain does not have to (and could not) bind together the trunk, boughs and leaves, or the colour and the shape, or the shape and the movement of the tree. One may see the tree clearly and distinctly or unclearly and indistinctly, and one may be sensitive to its colour and movement, or one may suffer from one or another form of colour-blindness or visual agnosia for movement. Which neuronal groups must simultaneously be active in order to achieve optimal vision, what form that activity may take, and how it is connected with other parts of the brain that are causally implicated in cognition, recognition and action, as well as in co-ordination of sight and movement, are what needs to be investigated by neuroscientists. Since seeing a tree is not seeing an internal picture of a tree, the brain does not have to construct any such picture. It merely has to be functioning normally so that we are able to see clearly and distinctly. It does not have to take a picture apart, since neither the visual scene nor the light array falling upon the retinae are pictures. It does not have to put a picture back together again, since what it enables us to do is to see a tree (not a picture of a tree) in the garden (not in the brain).

...

For the neural correlates, the various cells firing in the various locations of the 'visual' striate cortex, cannot be 'recombined', and do not need to be. The thought that the features a perceiver perceives must be correctly synthesized 'to form a separate object', the so-called 'binding problem', is confused. (For critical discussion see pp. 32-8.) To perceive is not to form an image of what is perceived, either in one's brain or in one's mind. What is perceived is the tree in the quad, not a representation of a tree in the quad. The brain does not have to synthesize a representation of the tree out of representations of its size, shape, colour and orientation - it has to enable the perceiver to see the tree and its features clearly. — History of Cognitive Neuroscience, pp37-38,55 - Bennett, M. R., Hacker, P. M. S.

our model of (some part of) the world and the world we are modeling sometimes match up. I think we essentially agree.
— Andrew M

Yeah. We have a vested interest in them matching up, not just with the world, but (and this is the really important part, for me) with each other's models. In fact I'd be tempted to go as far as to say that it's more important that our models match each others than it is they match the state they're trying to model. I'm pretty sure this is main function of many language games, the main function of social narratives, the main function of rational thought rules. To get our models to match each others. — Isaac

Certainly it's important for communication and co-operation. But it's worth noting that we have language not just for agreement and disagreement (i.e., whether our model matches up with other people's models), but also for being correct and mistaken (i.e., whether our models match up with the world we are modeling).

Consider a Robinson Crusoe on a deserted island who doesn't communicate with anyone. Mistakes in his world modeling can be costly (nope, no precipice there...)

Yes, it's the primary difficulty here. If I (as a scientist) am to explain what your 'seeing the rose in the garden' consists in, I can't very well give the answer "you're not seeing the rose in the garden". That didn't really answer the question. But equally, I'd be remiss if I didn't provide an explanation of how you can see the red rose out of the corner of your eye despite dendritic trees from the ganglia there being too complex to interpret colour from. You filled-in the colour you expected the rose to be, nothing to do with any physical activity in the actual garden. — Isaac

:up:

Because the 'red flower' I'm trying to model and the current 'snapshot' state of my model are not necessarily the same, and some of the reason they're not the same is expectation biasing the interpretation of (and occasionally outright suppressing) the sensory data. It's only the sensory data which is directly connected to the 'red flower', the thing I'm trying to model. The 'veil' is everything else which plays a part in the modelling process not caused directly (or even indirectly) by the 'red flower'. — Isaac

:up:

Then how is that not a 'veil'? If we can see a flower as red.but it isn't red, then what got in the way? Whatever got in the way - that's what I'm referring to as a 'veil'. — Isaac

So the phrase "veil of perception" has a historical connection with certain 17th century metaphysical views that deny any direct world-involvement. But your use of the term is different to that - you allow that we see things as they are at least some of the time which is sufficient to get a footing in the world. That is, our model of (some part of) the world and the world we are modeling sometimes match up. I think we essentially agree.

I think that's a gross deflation of all the work that neuroscience has done on this. Most of the neuroscientists I've spoken to or listened to consider themselves to be investigating the matter of what perception is as a scientific investigation, not one in philology. — Isaac

I'm sure that's so. However when we see a red flower, do we see it in the brain, or in the mind, or in the garden? I'm not suggesting this applies to you but without clarification of the terms involved, this is the kind of confusion that can arise. For example, from Bennett and Hacker:

The discoveries [of neuroscience] are no doubt splendid and fascinating - the conclusions sometimes drawn from them [eg that what we perceive are pictures in the brain (Crick), or `virtual reality' constructed by the brain (Smythies), or `movies in the brain' (Antonio Damasio)] are one form or other of latent nonsense (concealed transgressions of the bounds of sense) as we demonstrated in PFN. — Letter to the Editor: Reply to critical review by Professor John Smythies, Perception, 2011, volume 40

..

That is, this red flower here is the intended object of my perception.
— Andrew M

I agree with this. It's the 'realism' bit. The object we're all trying (with our modelling processes and our social interaction) to react to is the red flower, out in the world. I don't see how it being the object of our intention somehow removes the 'veil' between us and it. — Isaac

If you agree that there can be a red flower there that I can perceive, then I'm not clear why you're invoking a "veil". What exactly is being veiled here?

You're saying that any time we're mistaken about the properties of the object we've instead perceived nothing? If I perceive a flower, but in my mind it had red petals (I only briefly glanced at it). I return to it for a closer look and find I had merely assumed the petals were red - expectation bias - they were, quite clearly pink). Now I have to admit that I perceived nothing at all? — Isaac

The example I had in mind was a hallucination, which isn't perception. Yes of course there can be conditions where we see a flower that looks red (or assume is red), but isn't.

That seems like an odd position to take. It implies that science is a pointless exercise, forever subsumed by whatever it was we 'reckoned' was the case prior to its discoveries. We used to talk as if the sun went around the earth, we talk of sunrise, the 'movement' of the stars. Should we then say that cosmology needs to change how it talks because we had a prior linguistic convention which assumed a geocentric universe? — Isaac

Ordinary language allows the revising of claims in the light of new discoveries. One can be mistaken about what they think they're perceiving, e.g., that the sun is literally rising. In your example, people agreed on what the term "movement" meant. The dispute was instead a substantial one about which objects were moving.

The "perception" dispute is not like that. It's instead a disagreement over how the term is defined.

I think its a logical/linguistic issue. Our (public) use of words derives from our interaction with things in the world that we find ourselves a part of.
— Andrew M

I don't think they do, at least not exclusively. Our public use of words is derived as much from social beliefs, dynamics and feedback (often chaotic), as it is from the properties of objects. — Isaac

Yes, language emerges within a dynamic, relational context. We don't stand outside the world perceiving things from a God-eye's perspective.

The "veil of perception" is an alternative conception that breaks that logical dependency.
— Andrew M

I don't see how. They just seem like two models to me. Why does the fact that one of them governs everyday interaction (including interaction with brains, fMRI scans, EEG etc) and one of them govern talk about how minds work mean that one breaks a logical dependency on the other? — Isaac

Because the "veil of perception" model takes the ordinary term "image" (or "veil", or "representation") which is defined in terms of perceptible objects and then defines "perception" in terms of images (or veils or representations), which is circular. Also see the example below.

If I use an instrument which relies on electricity to investigate electro-magnetism my results are thus constrained. I'm not told "you can discover anything you like, but you cannot change how we think electro-magnetism works because the machine you're using relies on electricity" — Isaac

As I see it, it's like being told that the instrument completes its function indirectly because it relies on electricity. The point is that the instrument does what it is designed to do and uses electricity (or perhaps some other yet-to-be discovered means) to do it. There isn't a barrier in the way.

Similarly, the term "perception" does what it is designed to do. There's no barrier or veil in the way because the term "perceive" has been defined ostensively (which is to say, relationally between a perceiver and what is perceived). That is, this red flower here is the intended object of my perception. When I look and become aware that it is there, then I've perceived it. If I'm mistaken about what is there (because, like the above instrument's operation, things can sometimes go awry) then I haven't perceived anything.

Scientific investigation is a natural extension of everyday experience where the language and knowledge is simply more specialized. There doesn't need to be a conflict.

I'd just add that it doesn't then follow that we perceive images or, alternatively, respond to images. Instead we respond to things that we perceive, such as red flowers.
— Andrew M

But the latter doesn't follow either. I mean, I agree it doesn't necessarily follow that we respond to images (as in 'I have an image of my house on this USB stick'), simply from the fact that such a definition is plausible, but then it also doesn't necessarily follow that we respond to things we perceive from the the fact that such an definition is only plausible. Neither case has been made nor refuted. — Isaac

It's the way we ordinarily use our words. That thing there that I'm pointing to (cue, a red rose in a vase on the table) is what I understand a red flower to be. I can see it, take it out of the vase, and react if I drop it.

That a scientist could potentially put probes on my brain and view an image of what I'm looking at doesn't change anything about what I'm looking at.

I think a lot is made here of the status of an intermediary in the process of perception, which seems to be to be wrongly hinged on epistemological concerns when it's rightly more ontological.

That something causes us to respond when seeing (what we call) a red flower is not in dispute. That there are intermediary step between the flower an our conscious 'logging' of having seen it is also (I hope) not in dispute. — Isaac

I think its a logical/linguistic issue. Our (public) use of words derives from our interaction with things in the world that we find ourselves a part of.

There's no dispute that perception involves a physical process that can involve any number of steps. The dispute (if there is one here) is with the suggestion that we're not perceiving the things we ordinarily think we are - that we're instead subject to a "veil of perception" (i.e., that we're either perceiving images or else inferring things via an image).

The ontological commitment seems to be that the proper object is the first outside of our body. We could just as easily say it's the first outside of our conscious awareness. — Isaac

Yes, our perception starts with "medium-sized dry goods", so to speak - the everyday things we observe and interact with.

But perception is not limited to that. Brains aren't outside the body, yet we can open up a skull and see a brain. We can use a microscope to see neurons. And we learn that seeds (which we can also perceive) grow into flowers.

We can also use more abstract language - "image", "representation", "appearance" and so on. But those abstractions depend on the concrete things we perceive and interact with. The "veil of perception" is an alternative conception that breaks that logical dependency.

I agree that we respond to things that we perceive (such as red flowers). But I was referring to KK's "image of 'red flower'". Where does that fit into the "perception" story, on your view?
— Andrew M

Well I can't speak for Kenosha Kid's understanding (although I just did in my post to you, so... oops), but I think we can justifiably use the term 'image' to describe what exits the visual cortex. We're already not a million miles away from being able to directly decode the neural signal leaving that area into an actual computer image. Much like I might say "I have an image of my house here on this USB stick" — Isaac

Cool. I'd just add that it doesn't then follow that we perceive images or, alternatively, respond to images. Instead we respond to things that we perceive, such as red flowers.

I think we all had the "does separating out experience from perception create a perceptual intermediary + invite the Cartesian theatre criticism" discussion before. Somewhere around page 30 here. Jack Cummins may find the discussion of the article in that thread's OP useful. — fdrake

:up: Preparing for another 90 pages of this...

No, this is a misrepresentation. Kenosha Kid is not suggesting that we're 'looking' at images of flowers, the 'looking' is the name we give to the entire process. What @Kenosha Kid is referring to is our responses. Speech, action, emotional responses, strategies, and more complex mental reactions. These all result from the perception of the flower, not the flower. — Isaac

I agree that we respond to things that we perceive (such as red flowers). But I was referring to KK's "image of 'red flower'". Where does that fit into the "perception" story, on your view?

It's the assumption of an image between the perceiver and the object that suggests the dualism.
— Andrew M

For you maybe. To me it suggests retina. — Kenosha Kid

Sorry, you've lost me! See my question above.

Thee's the cartesian theatre.
— Banno

Do you seriously observe no difference between recognising that we don't have direct perception of objects and a full-on subscription to dualism? I get the comparison you're making, but unfortunately it's regarding uncontroversial statements about the brain. There's plenty of examples of the brain doing processing that we're not conscious of that feeds into stuff we are conscious of. I'm certainly not conscious of how photons get converted into an image of 'red flower', and anyone who pretends they are is full of it. Calling it a Cartesian theatre or humunculus is just misleading. — Kenosha Kid

It's the assumption of an image between the perceiver and the object that suggests the dualism. That's the Cartesian theater - that we're only ever looking at images of red flowers, never red flowers.

Can they use an electronic eye to see and record where the photon actually goes, and half the time delete the results before a human becomes aware of it and half the time let it known to a human? I want to know if the electronic eye is interfering with the experiment and collapsing the wave function, or if it is awareness by a conscious human being. — TiredThinker

It's possible to mark which slit a photon goes through and then later erase that mark. With a stream of marked and then unmarked photons, an interference pattern will be formed as per the original double-slit experiment. See the quantum eraser experiment. However, apart from that kind of carefully controlled experiment, once information leaks out into the environment (say, to an electronic eye) there is no practical way of erasing it and no interference pattern would form. That's the case even if no human ever learns which slits the photons went through.

Such a wavefunction does not exist. Dirac deltas are not eigenfunctions. They are distributions. — GraveItty

Yes, I was envisaging a wave function that just approximates those statistics. Also, welcome to the forum!

Obviously invented and projected upon physical reality. It's reasonable that math is effective. Math is derived from structures in the physical world. — GraveItty

And what is structure? I notice you give a nod to Aristotle in another post, who defined things in terms of matter and form.