Picture: dials. Libet’s famous experiments are among the most interesting and challenging in neuroscience; now they’ve been taken further. A paper by Fried, Mukamel and Kreiman in Neuron (with a very useful overview by Patrick Haggard) reports on experiments using a number of epilepsy patients where it was ethically possible to implant electrodes and hence to read off the activity of individual neurons, giving a vastly more precise picture than anything achievable by other means. In other respects the experiments broadly followed the design of Libet’s own, using a similar clock-face approach to measure the time when subjects felt they decided to press a button. Libet discovered that a Readiness Potential (RP) could be detected as much as half a second before the subject was conscious of deciding to move; the new experiments show that data from a population of 250 neurons in the SMA (the Supplementary Motor Area) were sufficient to predict the subject’s decision 700 ms in advance of the subject’s own awareness, with 80% accuracy.

The more detailed picture which these experiments provide helps clarify some points about the relationship between pre-SMA and SMA proper, and suggest that the sense of decision reported by subjects is actually the point at which a growing decision starts to be converted into action, rather than the beginning of the decision-forming process, which stretches back further. This may help to explain the results from fMRI studies which have found the precursors of a decision much earlier than 500 ms beforehand. There are also indications that a lot of the activity in these areas might be more concerned with suppressing possible actions than initiating them – a finding which harmonises nicely with Libet’s own idea of ‘free won’t’ – that we might not be able to control the formation of impulses to act, but could still suppress them when we wanted.

For us, though, the main point of the experiments is that they appear to provide a strong vindication of Libet and make it clear that we have to engage with his finding that our decisions are made well before we think we’re making them.

What are we to make of it all then? I’m inclined to think that the easiest and most acceptable way of interpreting the results is to note that making a decision and being aware of having made a decision are two different things (and being able to report the fact may be yet a third). On this view we first make up our minds; then the process of becoming aware of having done so naturally takes some neural processing of its own, and hence arrives a few hundred milliseconds later.

That would be fine, except that we strongly feel that our decisions flow from the conscious process, that the feelings we are aware of, and could articulate aloud if we chose, are actually decisive. Suppose I am deciding which house to buy: house A involves a longer commute while house B is in a less attractive area. Surely I would go through something like an internal argument or assessment, totting up the pros and cons, and it is this forensic process in internal consciousness which causally determines what I do? Otherwise why do I spend any time thinking about it at all – surely it’s the internal discussion that takes time?

Well, there is another way to read the process: perhaps I hold the two possibilities in mind in turn: perhaps I imagine myself on the long daily journey or staring at the unlovely factory wall. Which makes me feel worse? Eventually I get a sense of where I would be happiest, perhaps with a feeling of settling one alternative and so of what I intend to do. On this view the explicitly conscious part of my mind is merely displaying options and waiting for some other, feeling part to send back its implicit message. The talky, explicit part of consciousness isn’t really making the decision at all, though it (or should I say ‘I’?) takes responsibility for it and is happy to offer explanations.

Perhaps there are both processes in involved in different decisions to different degrees. Some purely rational decisions may indeed happen in the explicit part of the mind, but in others – and Libet’s examples would be in this category – things have to feel right. The talky part of me may choose to hold up particular options and may try to nudge things one way or another, but it waits for the silent part to plump.

Is that plausible? I’m not sure. The willingness of the talky part to take responsibility for actions it didn’t decide on and even to confect and confabulate spurious rationales, is very well established (albeit typically in cases with brain lesions), but introspectively I don’t like the idea of two agents being at work I’d prefer it to be one agent using two approaches or two sets of tools – but I’m not sure that does the job of accounting for the delay which was the problem in the first place…

(Thanks to Dale Roberts!)

101 Comments

  1. 1. Peter says:

    Oops – comments should not have been turned off.

  2. 2. Arnold Trehub says:

    Peter: “The willingness of the talky part to take responsibility for actions it didn’t decide on and even to confect and confabulate spurious rationales, is very well established (albeit typically in cases with brain lesions), but introspectively I don’t like the idea of two agents being at work I’d prefer it to be one agent using two approaches or two sets of tools – but I’m not sure that does the job of accounting for the delay which was the problem in the first place…”

    I assume that the “talky part” you mention is our inner speech. The delay must naturally occur because all of the cognitive work involved in analyzing a situation and arriving at a response/decision (including the evocation of conscious inner speech) is completed in the brain’s preconscious mechanisms *before* it is projected into our brain representation of egocentric space where it is consciously experienced as *something somewhere* with respect to our core self (I!). This is illustrated in Fig. 8, here:

    http://people.umass.edu/trehub/YCCOG828%20copy.pdf

    In other words, we can think of consciousness as the brain’s representation of our current situation in the world based upon the spatiotemporal registration of excitatory projections into egocentric space that originate in non-conscious sensory-cognitive mechanisms. If this is the case, then there *must* be a time lag between direct measurements of a decision in the preconscious brain mechanisms and the later phenomenal experience of making a decision. So there really are not two agents at work. There are many neuronal agents at work, but their conduct is hidden from us, and it is only the product of their work that becomes part our phenomenal world, which we can experience only in perspectival relation to ourself (I!) as the origin of our phenomenal world. In this situation we have experiential evidence (though false) of no other agent but our self.

  3. 3. John says:

    I believe Arnold is right about inner speech. What does conscious experience DO? Loss of consciousness, whether by anaesthetic, a blow on the head, sleep, delirium, PVS, mutism etc. always results in a cessation of directed activity and a lack of voluntary recall of the time spent unconscious (although some stimuli administered during anaesthesia can be recognised later). So conscious experience is required for the coordination of brain activity and for laying down recallable memory. Thats what it does.

    A geometric form such as conscious experience is an organised array of data, it is coordinated by its very nature so the coordination role of conscious experience should not surprise anyone. However, coordination can also be performed by running a program that has no geometrical form so why a geometric form is the method of choice in the brain should be a clue about the deeper nature of conscious experience.

  4. 4. Peter says:

    Arnold, as always what you say makes perfect sense. But isn’t there a residual uneasiness about the apparently epiphenomenal role of the ‘talky part’ (I’m lazily assuming that inner speech, outer speech, clear but non-verbal interior reflection and for that matter the authorship of blog posts, all have the same origin)?

  5. 5. John says:

    Sorry to butt in Peter but the “talky part” cannot be epiphenomenal when it is acoustic speech and if you listen to inner speech, perhaps by saying a word out loud and then sayng it internally you will notice that they are very similar in content and location. MRI scans show a huge overlap of the parts of the brain used during inner speech with those used during acoustic speech. The apparently epiphenomenal part is the experience containing either inner or acoustic speech, not the brain activity or the acoustical waves.

  6. 6. Gilbert Wesley Purdy says:

    Glad to see that things remain higly interesting here. Peter, I think you are more or less aware of my thoughts about the role of consciousness. Surely, there is a range of cooperation between the conscious and the subconcious. Libet (et alii) are necessarily based upon simple tasks thus the relationship between the conscious and subconscious is simple and the processing rates are fast. Deciding upon what house to buy, however, requires much more involvement from the conscious and is correspondingly slower. In particular, the memory called upon in order to successfully make the decision is a higher order than is available to the subcortical/paleo-mammalian memory areas. The operations on the contents of the memory are more complex, and, therefore, need the computing power of the frontal cortex. We have evolved, over millions of years, to the point where we make “more civilized” (better thought out) decisions than our more subconciously dominated forebearers.

  7. 7. Peter says:

    Thanks John – you’re right, epiphenomenal acoustic speech doesn’t seem to make much sense.

    Hi Gilbert! Good to hear from you.

  8. 8. John says:

    Peter, the strange aspect of experience is that it is like an observation of a virtual reality created by the brain that is used to coordinate and stabilise brain processing. Virtual realities are essential in complex navigational systems. The virtual realities in these systems are usually programmatic in that they have positions and progress coded as numbers representing vectors. We are different from most navigational computers because we have a geometrical virtual reality that contains simultaneous objects that represent the objects in the world and their relationships. But it gets weirder, in principle there is no need for awareness, no need for the geometrical virtual reality to be our experience, it can just be a cog in the machine of the brain like a programmatic virtual reality. It is this lack of any need for experience that makes it apparently epiphenomenal.

    Things get weirder still when Libet’s discoveries are taken into account. Your article is about the “readiness potential” but Libet also discovered a delay between sensation and experience of 0.5 seconds which has been confirmed by subsequent experiments. Not only is our experience an apparently unnecessary observation of a system that does not seem to need observation, it is also 0.5 seconds late. Our conscious experience occurs too late to control most behaviour, including speech, and so must be largely epiphenomenal.

  9. 9. Arnold Trehub says:

    John: “Our conscious experience occurs too late to control most behaviour, including speech, and so must be largely epiphenomenal.”

    I’m puzzled by this statement. Our conscious experience is constituted by the content of our phenomenal world (retinoid space) in the extended present. All of the phenomenal features in this egocentric world (1pp) are systematic analogs of our physical world (3pp), having the constraints to which we are tasked to successfully respond. Would you consider an accurate road map an epiphenomenal thing because it does not directly cause you to travel any of its marked routes? I wouldn’t! Because if I am motivated to drive from Amherst, MA to New York City (or any other place), the map provides the necessary visual-cognitive excitation to evoke in my brain the proper travel routines. So it is with conscious experience. See here:

    http://journalofcosmology.com/Consciousness130.html

  10. 10. John says:

    Arnold: “Would you consider an accurate road map an epiphenomenal thing because it does not directly cause you to travel any of its marked routes? I wouldn’t! Because if I am motivated to drive from Amherst, MA to New York City (or any other place), the map provides the necessary visual-cognitive excitation to evoke in my brain the proper travel routines. So it is with conscious experience.”

    Suppose the events on the map, such as the motion of your body that changed the position of your current location indicator on the map, occurred 0.5 secs after your senses registered the motion and 0.25 secs after your muscles responded to these sensory inputs. Would this be an example of the map evoking the proper travel routines or would the map be a passive display of what was occurring in the world and brain?

    It is the timings that were found by Libet in his investigations of the relative roles of the cerebral cortex and thalamus in sensory perception that are the real conundrum for philosophy of mind, not the “readiness potential”. These timings show that sensory events appear in our experience 0.5 secs after the stimulus. Given that motor responses occur 0.25 secs after sensory stimulation this means that experience is 0.25 secs behind action. How can an event that occurs after an action be the motivator of the action?.

    Libet’s findings have been extended by investigations into perceptual masking and perceptual filling-in of motion and studies of the late phase of the ERP in EEG experiments, all of which reinforce his original discovery of the 0.5 sec delay.

    However, even if experience were not delayed there would still be a problem of apparent epiphenomenalism if a process driven description of the brain is used. Processes are successions of classical state changes such as the state changes in the memory of a digital computer or the state changes in the cogs of a windmill. A processing machine is computing this output using a process in the preceding seconds or minutes before it occurs so, by definition, the output is not in the machine before it happens. The output of a process occurs when it occurs, it is not known beforehand. This means that if the workings of the machine are displayed it is not until the output occurs that it is known that the output has occurred. A decision is an output of processing so we only know our decisions once they are taken, there was no need for the readiness potential experiments to demonstrate this point, it is a simple, logical inevitability. If we watch our minds at work we can observe decisions popping into mind. A mind that has decisions popping into it is apparently epiphenomenal.

  11. 11. John says:

    Arnold, this business of epiphenomenalism is very important in the philosophy of mind and the “ghost in the machine” has driven many people away from an empirical approach. If you can persuade me that I am wrong about it I will actually be pleased! To recap, I am arguing that events in experience largely occur after actions so cannot cause these actions and even if events in experience occurred ‘pari passu’ with actions all that would be within experience is a passive canvass being painted by non-conscious processes. I can only conclude from these considerations that conscious experience is not an active agent but is some sort of stabiliser of brain activity.

  12. 12. John says:

    Gilbert – see (10) and (11). Even if conscious experience operated simultaneously with complex tasks there would still be a problem with apparent epiphenomenalism.

  13. 13. Arnold Trehub says:

    John, you wrote:

    “To recap, I am arguing that events in experience largely occur after actions so cannot cause these actions and even if events in experience occurred ‘pari passu’ with actions all that would be within experience is a passive canvass being painted by non-conscious processes. I can only conclude from these considerations that conscious experience is not an active agent but is some sort of stabiliser of brain activity.”

    If “events in experience” are events in a particular part of the brain (say *C*), and “actions” are events in a different but synaptically-connected part of the brain (say *not-C*), and if *C* and *not-C* are in a recurrent feedforward-feedback loop of excitatory activity (as in the retinoid model), then what happens BEFORE and what happens AFTER depends on how one probes the *C*-*not-C* system.

    For example:

    t ———————————————–>t+n

    *C*–>*not-C*–>*C*–>*not-C*–>*C*–>*not-C* …… etc.

    If this is the case, why should we think of conscious experience as epiphenomenal?

  14. 14. Tom Clark says:

    Arnold:

    “If “events in experience” are events in a particular part of the brain (say *C*), and “actions” are events in a different but synaptically-connected part of the brain (say *not-C*), and if *C* and *not-C* are in a recurrent feedforward-feedback loop of excitatory activity (as in the retinoid model), then what happens BEFORE and what happens AFTER depends on how one probes the *C*-*not-C* system.
    For example:
    t ———————————————–>t+n
    *C*–>*not-C*–>*C*–>*not-C*–>*C*–>*not-C* …… etc.
    If this is the case, why should we think of conscious experience as epiphenomenal?”

    It’s of course the case that if events of experience are the same thing as events in the brain (the NCC turn out to *be* consciousness), then they aren’t epiphenomenal with respect to behavior (on the assumption that there are causal links between the NCC and behavaior). But if experience is a set of “systematic analogs” with brain events, then it isn’t clear how it does any causal work, since such work is already accounted for by the NCC.

  15. 15. John says:

    Arnold and Tom, I tend to agree with Tom’s point. The retinoid array is not epiphenomenal but the experience containing the array seems to be epiphenomenal. But perhaps there is a wider problem here of the philosophy of causality. The instantaneous state of a digital computer is epiphenomenal in the sense that no-one can say exactly how it becomes the next state. If we track back within the computer to the clock that provides the signal to shift states we must explain harmonic motion but harmonic motion can be described but not explained as I will argue below using the standard notion of kinetic energy in modern physics.

    Harmonic motion is due to the continuous interconversion of kinetic and potential energy, kinetic energy is due to a shift in temporal path through a four dimensional manifold which endows a particle with increased inertia (crudely expressed as (change in inertial mass) * c^2). However, if the 4D manifold exists then we have a block universe and nothing moves; it is only the passing of time in the observer that endows the system with the passing of time that permits the inertial mass changes etc to be registered as continual exchanges between potential and kinetic energy. So perhaps the only thing that is not epiphenomenal is the observer, which is a complete inversion of the normal argument about epiphenomenalism.

  16. 16. Arnold Trehub says:

    Tom and John,

    Tom: “It’s of course the case that if events of experience are the same thing as events in the brain (the NCC turn out to *be* consciousness), then they aren’t epiphenomenal with respect to behavior (on the assumption that there are causal links between the NCC and behavaior). But if experience is a set of “systematic analogs” with brain events, then it isn’t clear how it does any causal work, since such work is already accounted for by the NCC.”

    It seems to me that the events of conscious experience are: (a) the same thing as particular physical events (most likely biophysical events in the brain), or else (b) the events of conscious experience are not the same thing as particular physical events.

    If (b) then we have substance dualism and all scientific bets concerning consciousness are off the table.

    Because science is a pragmatic enterprise, we can entertain (a) within a non-reductionist dual-aspect monistic framework while we adopt the strategy of searching for corresponding analogs between conscious events and biophysical events in scientific practice.

  17. 17. Charles Wolverton says:

    “we can entertain (a) within a non-reductionist dual-aspect monistic framework”

    This is consistent with Davidson’s “anomalous monism” as updated per Ramberg in the essay to which I (tediously – sorry) keep referring.

    This latest sequence of comments confirms my suspicions that we are all mostly in agreement although each participant expresses the common points in somewhat different vocabularies. With a little more Davidsonian “triangulating”, we might even converge on a common one – which IMO would be a huge leap forward.

  18. 18. John says:

    Arnold: “It seems to me that the events of conscious experience are: (a) the same thing as particular physical events (most likely biophysical events in the brain), or else (b) the events of conscious experience are not the same thing as particular physical events.”

    Option (a) applies but most neuroscientists are under the impression that a succession of 3D slices of the world can always be assembled to describe reality. This is not the case. A succession of two dimensional slices of a chair seem to be the same as a chair but each slice is actually an abstraction and could not exist. So it is with our analysis of the brain. We describe it in terms of a succession of three dimensional slices but a 3D slice cannot exist, nothing exists for no time at all. Worse still, if you assemble a 3D model from 2D slices you can just pile up the slices to make the model. When moving from 3D to 4D the geometry is not simply additive in this way (see An introduction to New Empiricism).

    The successions of 3D slices that neuroscientists call a “scientific” description of the brain do not even contain a proper idea of energy. Energy is a property of four dimensional systems and cannot exist in 3D. As I tried to explain in my previous post, the average scientific description of the world is epiphenomenal. It cannot initiate change.

    The mystery of conscious experience is how we can hear whole words and movement. I know I exist because the “I” and the “exist” are there together in my experience. I do not need to take data that represents a microsecond of the word “I” and symbolise it, then the next microsecond and symbolise this and so on, then place the symbols in a store then run a program to compare the symbols and end up with a store that is a 3D symbol that would mean “I exist” if I run it through the steps of a program to create a store that means “I exist” if I run it through the steps of a…

    My experience is not 3D it is 4D and so contains motions that embody “directedness” or “intention”. The explanatory gap is no more than a resolute refusal amongst neuroscientists to accept that they may need to advance their physical knowledge so that it is at least compatible with physics a century ago.

    Charles, the “non-reductionist dual-aspect monistic framework” is an expression of the problem described above. The world is multidimensional but technicians and philosophers are trained to believe it is three dimensional. When their abstract 3D slices cannot be slotted together to describe reality it is tempting to simply accept this rather than to turn to the physics books and ask if 3D abstractions are known to be imprecise/mistaken/inapplicable in some circumstances etc..

  19. 19. Vicente says:

    John, this is really food for thought, thanks.

    The mystery of conscious experience is how we can hear whole words and movement. I know I exist because the “I” and the “exist” are there together in my experience. I do not need to take data that represents a microsecond of the word “I” and symbolise it, then the next microsecond and symbolise this and so on, then place the symbols in a store then run a program to compare the symbols and end up with a store that is a 3D symbol that would mean “I exist” if I run it through the steps of a program to create a store that means “I exist” if I run it through the steps of a…

  20. 20. Vicente says:

    John, How can we hear words?

    I agree that storing and comparing wouldn’t work…

    Could it be that the brain uses a real-time selection tree function? like the text-input help of google text box, or word-processors that offers you possibilities to finish a certaing word or a statement.

    So once the brain “hears” the beginning of a word for example “m”, all possible words starting with m are selected opening the tree, when the next sound comes “u” it prunes the tree and only the branches for “mu…” are left, the final “m” + silence evokes the word mum, and you have the impression (illusion?) of hearing the word in a time sequence.

    Actually this is an old tool for comedians, to start saying a word that is most likely to be guessed than the one they actually utter, creating surprise and laugh. At some point people guess the the whole word…

    Of course how to define the time units for this model to work, and how to structure phonetics in smaller time slots is complicated, and I don’t know if there is any human semantic memory access model that considers this approach.

    Well, James consciousness flow idea as a scenes sequence is sometimes difficult to fit.

  21. 21. John says:

    Vicente: “So once the brain “hears” the beginning of a word for example “m”, all possible words starting with m are selected opening the tree, when the next sound comes “u” it prunes the tree and only the branches for “mu…” are left, the final “m” + silence evokes the word mum, and you have the impression (illusion?) of hearing the word in a time sequence.”

    Do you have the “illusion” of hearing whole words and seeing movements or are they actually arranged in time? Watch someone speak, the words occur at their lips, the phonemes do not overlap each other but are separate at the position of their lips. This strongly suggests another direction for arranging events.

    In fact we colloquially call this extra direction for arranging events “time”. So why do philosophers and some scientists absolutely and resolutely reject the possibility that experience might be arranged in time as well as space? The simple answer is that they have an intellectual model of time, a theory, that does not correspond to the reality of time and they have the hubris to reject observation in favour of their erroneous theory.

    Curiously the “erroneous theory” is not the theory of time that is current in science, it is a peculiar idea of time that is current amongst high school graduates. We should ditch high school science and try to explain our experience: if experience seems evidently four dimensional we should be happy to turn to four dimensional physics, after all, the universe IS four dimensional.

  22. 22. Arnold Trehub says:

    John: “When their abstract 3D slices cannot be slotted together to describe reality it is tempting to simply accept this rather than to turn to the physics books and ask if 3D abstractions are known to be imprecise/mistaken/inapplicable in some circumstances etc..”0

    As you know, I take retinoid space to be a 4D manifold having what might be called an “extended present”. Its *description/depiction* is an artifact that can only be *shown* as a 2D or 3D structure. The problem is that ANY scientific model of the world can only be an approximation of the reality that is modeled. This is as true of the models of physics as it is of the models of neuroscience. Electromagnetic waves, for example, are conventionally depicted in 2D as amplitude traces over time, even though we conceptualize them as events in 4D.

    John: “The mystery of conscious experience is how we can hear whole words and movement.”

    Why should this be a mystery if the egocentric biophysical retinoid space that constitutes conscious experience has a memory that holds its content, albeit with decaying amplitude, over time through a phenomenally extended present? When you think “I exist”, “I” and “exist” are arranged together and experienced together in retinoid space during the extended present.

  23. 23. Charles Wolverton says:

    John -

    I don’t see that vocabulary irreducibility orlanguage untranslatability and the related issues of dual-aspect or anomalous monism have anything to do with whether philosophers and neuroscientists are comfortable with multivariate functions for which one of the variables is “t” (ie, time). Having neither background nor contacts in either of those disciplines (other than via blogs such as this), I may not be representative of people interested in these issues, but as a comm systems analyst with substantial background in various areas of abstract math I am quite comfortable with such functions and can’t quite grasp why you consider them worth making such a fuss about.

    Language is a form of analog comm, which has been familiar to comm engineers for a century or so, and it comes naturally to me to think of the basic unit of language “decoding” as being a “word” (in the information coding sense, not the linguistic sense), and I’ve actually come to suspect that the basic coding unit of spoken language is closer to a phrase or sentence than to a linguistic “word”, never mind a phoneme. In fact, I wouldn’t be surprised if there is even a context dependency that speeds the “decoding” process. Ie, I see those coding units as possibly being spread over a relatively large time interval and possibly over additional contextual “dimensions”.

    Or perhaps I’m missing your point.

  24. 24. Vicente says:

    John,

    It is definitely a problem… for the case of movements I really don’t see how to “pack” in one single conscious instant, the present and the near past, so that we can perceive fast environment change, movement or any correlated events chain…

    This fact supports my own idea that phenomenal experience is a complete different realm, that is created somehow, somewhere. So as part of the input needed to create the conscious perception of the world, a time period (near past) content is somehow stored in a “pile / stack / heap” and then used (compressed?) to created an instataneous feeling of movement. It seems to me that additional dimensions even over 4D would be needed to do so in 4D real time…

    Or maybe we just work on a frame by frame basis, and it is just the changes detected between correlative frames that cause the illusion of movement, but then I agree with you that it is difficult to see how can we hear and understand complete words, for which the whole frames sequence is required at a precise instant. That is why a proposed the selection tree mechanism, to skip the need of the whole word “conscious frames” present at one instant.

    Are there any experiments about the time gap between a word being heard and the subject reporting about it? like Libet’s but with words instead of decisions… that could discard the storing and comparing model.

    I have the feeling that we operate on the peak of a propagating pulse, in which consciousness in the integral of the pulse, that accounts for the whole time axis, with main contribution in the near past and future, tending to zero at the tails…

  25. 25. John says:

    Vicente: “…, a time period (near past) content is somehow stored in a “pile / stack / heap” and then used (compressed?) to created an instantaneous feeling of movement”

    The geometry of a space is summarised by pythagoras’ theorem. The properties of a two dimensional euclidean space can be derived from:

    dh^2 = dx^2 + dy^2

    of a three dimensional Euclidean space from:

    dh^2 = dx^2 + dy^2 + dz^2

    of a four dimensionsal EUCLIDEAN space from

    dh^2 = dx^2 + dy^2 +dz^2 + dm^2

    But our four dimensional space is NON EUCLIDEAN, the reason time is peculiar is because it is a negative dimension in the metric:

    ds^2 = dx^2 + dy^2 +dz^2 – dt^2

    A non-Euclidean geometry can achieve exactly what you want, content can be in a “pile / stack / heap” given by locations with:

    dh^2 = dx^2 + dy^2 +dz^2

    but then also at an instantaneous point given by:

    0 = h^2 – t^2

    What is going wrong in the philosophy of mind is that philosophers and neuroscientists are fixated on a Euclidean idea of time (dh^2 = dx^2 + dy^2 +dz^2 + dm^2) so that 3D slices are stacked up to make a temporal sequence. But time does not work like this, it is what makes spacetime non-euclidean.

  26. 26. John says:

    Charles: “I am quite comfortable with such functions and can’t quite grasp why you consider them worth making such a fuss about. ”

    See post (25). The arrays of bits in communications and computing devices conform to the fact that current measuring instruments can only take a 3D snapshot of reality. In fact these devices artificially conform to our measuring technology and are composed of successions of 3D states. If we could measure a 4D state then our computers would be 4D but it is only in the past five years that we have been able to demonstrate interference effects in the time domain let alone routinely measure a 4D state.

  27. 27. Tom Clark says:

    John in 15:

    “However, if the 4D manifold exists then we have a block universe and nothing moves…”

    Seems to me on the block universe view movement is only created by the conscious appreciation of a succession of 3D states, with the experienced succession and duration being what we call the flow of time. So, I’d hazard to say that it isn’t as if nothing moves in the block universe, it’s rather that both movement and immobility don’t apply to it outside experience and our experience-based descriptions of events unfolding along the time axis.

  28. 28. Vicente says:

    John,y
    OK, but for events in the brain and ordinary interactions, the euclidean approximation works pretty well… I could undertand that fitting consciousness into the brain might require a quantum approach, but I dont’t see relativistic corrections needed for this system…. Maybe I haven’t really understood your point, I thought you were refering to a memory and information management problem resulting from “psychological time” concept… and that adding dimensions to the system could help to solve it.

  29. 29. John says:

    Vicente: “Maybe I haven’t really understood your point, I thought you were refering to a memory and information management problem resulting from “psychological time” concept… and that adding dimensions to the system could help to solve it.”

    I was starting from a scientific rather than a technical approach. In a technical approach we take existing theory and use this to describe events. In a scientific approach we take our observation and attempt to describe this with a theory. My observation has events arranged in space and time. It is clearly a spacetime of some sort.

    Vicente: “for events in the brain and ordinary interactions, the euclidean approximation works pretty well…”

    Yes, within the domain of applicability of school physics this physics works OK. But everyone knows that school physics is just a reduced set of the real thing and cannot be used to describe events that are outside of its domain. You only need to look at this screen and track back the light to realise that the high school student will have no chance of explaining the view with their limited set of theories. All that I am asking is that we look at our observation and work from the description of that observation back to theory. I have pointed out that when I do this myself my observation is more like reality than being like school physics.

    As for placing your hope in quantum approaches without relativity, this suggests that you do not believe that time exists. See The excellent Wikibook on Special Relativity then take a look at any modern, advanced textbook such as Sean Carroll’s excellent Lecture Notes on General Relativity which says the same thing using more advanced maths. Part of the love of QM by those who reject relativity is due to the pervasive use of the Schrodinger equation rather than the Lorentz invariant Dirac Equation which explains spin, anti-matter etc.

  30. 30. John says:

    Tom: “Seems to me on the block universe view movement is only created by the conscious appreciation of a succession of 3D states, with the experienced succession and duration being what we call the flow of time.”

    Yes, I suspect that “time” is a label for at least two linked phenomena. Dimensional time is a geometrical dimension which contributes the negative part of the signature of the metric tensor of spacetime (ie: it is an axis for arranging things in a non-euclidean geometrical manifold with a signature +++- or —+). Time passing is a phenomenon that shifts the location of the observer in a 4D manifold. Time passing is linked to entropy. It is manifest in my observation by the way that events always appear from earlier to later, for instance “hello” should really be in my observation as “olleh”, even if it were time extended, but somehow it is oriented in the correct direction. I am tempted to suggest that time passing is to do with my observation point moving forward in time but this observation point is clearly no more than the centre of the manifold of events and nothing in itself. Another suggestion is that time passing is a fifth, time like dimension…

  31. 31. Arnold Trehub says:

    John: “Time passing is a phenomenon that shifts the location of the observer in a 4D manifold. Time passing is linked to entropy. It is manifest in my observation by the way that events always appear from earlier to later, for instance “hello” should really be in my observation as “olleh”, even if it were time extended, but somehow it is oriented in the correct direction.”

    Your comment highlights the fallacy of the “*observer*”. There is *no observer* in the egocentric space-time of the retinoid. There is only a *phenomenal experience in the extended present* — a perspectival manifold with short-term memory organized around a fixed locus of origin, which is the core self (I!). “hello” is not experienced as “olleh”; it is experienced holistically in the *extended present* as the phonological sequence “hello”, with diminishing saliency over time from the “o” to the “h”.

  32. 32. Vicente says:

    John, there is no domain of applicability of school physics, there is a domain of applicability for the range of values of certain parameters. I don’t see that the distribution of matter and energy in the brain causes a distorsion in the metric tensor that requires a general relativity formulation, it is not a star. Regarding Dyrac’s equation… well when the range of energies requires a relativistic correction, let’s do it, of course. First, we should identify the quantum processes involved in consciousness and then see the best formulation to treat them, maybe no relativistic corrections are required. Nevertheless I agree that the more general a formulation is the best, it is easier to move from the general to particular. Why am I denying the existence of time?

    Recalling your comment about harmonic movement and the computer clock, an electronic oscillator (necessary ) has little to do with potencial and kinetic energy interconversion, it is not a pendulum or a spring, which by the way only have a harmonic movement in first order approximation solutions, since you like so much not to neglect terms. Actually all the kinetic energy in the circuit is dissipated and resupplied in each cycle by the power source.

    John are you bluffing?

  33. 33. John says:

    Arnold: ““hello” is not experienced as “olleh”; it is experienced holistically in the *extended present* as the phonological sequence “hello”, with diminishing saliency over time from the “o” to the “h””

    I can see that if the parts of a word were placed in a system that shifted them over time to increasingly less salient locations then the word would have a direction. Effectively the phonemes might be laid out successively along a sheet of neurons at ever increasing distance from a locus that acts as “now” (even though that “now” would be 200-250 ms late and the sheet would contain events covering, say, 300 ms). This would allow the system to “snuff out” whole words when their time was up in the same way as whole words suddenly disappear from our experience. The whole sheet would form a 4D geometrical manifold as in the first possible interpretation in The Value and Interpretation of Meditations.

    I have a concern in that article about how such a sheet of neural events might be laid out to separate the phonemes so that they are present at the same instant but laid out as if in time. If we were truly talking about a sheet then the problem could be resolved by curling the sheet with distance from the events that are nearest to “now”. Unfortunately the sheet must actually be a volume of neurones to account for perception over the whole of the space of experience so I still cannot see how the parts of a word are kept separate in experience.

    If such a layout were possible it would make Tom’s (and my own) misgivings about the passing of time into a problem of the non-conscious part of the brain.

  34. 34. John says:

    Vicente: “an electronic oscillator (necessary ) has little to do with potential and kinetic energy interconversion, it is not a pendulum or a spring, which by the way only have a harmonic movement in first order approximation solutions, since you like so much not to neglect terms”

    Are you sure that periodic motions do not always involve a discharge and recharge of potential energy? There is no requirement for the kinetic component of both the discharge and the recharge to be supplied by the potential energy source but one or the other must involve it to produce periodic changes in potential of a fixed period. As an example, a simple RC discharge has a time constant due to the conversion of potential energy in the capacitor to kinetic energy in the passive components. This time constant can be used to trigger a recharge cycle that produces kinetic energy from an external source of potential energy such as a battery that recharges the capacitor. The overall process is still an interconversion of potential and kinetic energy.

    Vicente: “I don’t see that the distribution of matter and energy in the brain causes a distortion in the metric tensor that requires a general relativity formulation, it is not a star.”

    I think that the crucial difference between our viewpoints occurred in your previous post where you pointed out that simple physical ideas were sufficient to explain the behavioural effects of the brain. I agree. Where we disagree is that I do not believe that conscious experience itself usually creates behavioural effects (see post (10)). Certainly the content of conscious experience may create behavioural effects and it is this fine distinction that keeps on causing disagreements between Arnold and myself.

    My point is that conscious experience has a “form” as well as a content and it is this form that appears to be epiphenomenal. The form is very clear, just look at the view around you, it has simultaneous events that appear to be separate from a central point and contains whole series of events such as whole words. But according to school physics this form cannot exist and forms do not do anything. It is quite evident that without the presence of the form the brain is severely compromised, it is unconscious, so the form does something related to stabilising the brain. I am proposing that we start from the phenomenon of the “form” and derive a theory that will explain it. The form involves time so the physics of spacetime are a good place to start. The universe is, after all, non-euclidean and the fact that behaviour can be explained by 3D approximations is a non-sequitur if we are analysing something that is apparently epiphenomenal.

  35. 35. John says:

    ps: you said that “I don’t see that the distribution of matter and energy in the brain causes a distortion in the metric tensor”. I agree, my point was purely that the brain sits in a non-euclidean spacetime, not that it bends it! There is no need for Penrose’s ideas in what I am proposing.

  36. 36. Arnold Trehub says:

    John: “My point is that conscious experience has a “form” as well as a content and it is this form that appears to be epiphenomenal.”

    1. How would your “form” differ from the representation of a volumetric space around a fixed origin (I! in retinoid space)?

    2. If selective excursions of the excitatory activity of I! — selective attention — is *needed* to parse and capture any other content in retinoid space for the processes of perception and adaptive behavior, are we justified in calling the activated I! epiphenomenal?

  37. 37. Vicente says:

    OK, Just a clarification I don’t know if physics (school, caltech, MIT or Sierra Leona IT) explain the behaviour of the brain, probably not for the moment. You have to differentiate between understanding the physiology of the brain as a body organ, and understanding the workings of the brain as a “cognitive organ”, both are related but not indentical. Similarly, the workings of a processor are related to solid state physics and theory of circuits but it requires of and additional logical layer (its architecture) in order to have a global overall view of the device.

    BTW, semiconductor theory does not require Dyrac’s equation to achieve its main successes. Schrödinger did it on his own devices ;-) .

    What I am sure is that physics in its current state of progress does not explain consciousness at all. I agree with you that space and time, as fundamental categories need to be incorporated to a theory of consciousness in the first place, which has not been done for the moment.

    You might be right in that “form” is a good starting point. It did work for psychologists (or not…) with the “gestalt” current.

    Regarding the oscillator, well… if you track back the energy source to the very origin, maybe fusion reactions in power stations, with fuel created in the gravitational collapse of gas… I don’t know… but the oscillator is just an unstable amplifier, not a tank circuit in which you move electric potencial energy of the capacitor to potencial magnetic energy of the induction and so on….(still I don’t find the kinetic energy).

    It is like this, when you want it to amplify is oscillates, and when you want the oscillator it amplifies, one of the most frustrating lab practices for students.

    Finally the core point, epiphenomenal mind !! I don’t know… could be, I believe not, but I have no evidence. Actually I believe that one of the goals in life is to kill the zombie, to take control, to be fully conscious every single instant. To me, Epiphenomenalism is being an idiot watching what the wimmy autonomous modules of your brain do. But who knows.

  38. 38. John says:

    Arnold, If I wired a house I could lay out the wires on the distribution board according to the layout of the house with the connections for each room in separate little rectangles but there is no real need to do such a thing so long as the correct wires are interconnected. Form is not required for function. I could model retinoid functionality in a digital computer and the layout of the nodes and connections would might bear no relation at all to the geometry of events in the world. The form of the retinoid system would not appear to be needed for its function. I think this answers both of your questions, a specific form is not needed for the “I” or for activity in retinoid space.

    Yet the brain usually preserves a topological mapping of events and our experience conforms to this mapping. But form is not required for function, the form appears to be epiphenomenal. Despite this we find that the form of events is crucial to making our conscious experience what it is. As Vicente says:

    Vicente: “Finally the core point, epiphenomenal mind !! I don’t know… could be, I believe not, but I have no evidence. Actually I believe that one of the goals in life is to kill the zombie, to take control, to be fully conscious every single instant. To me, Epiphenomenalism is being an idiot watching what the wimmy autonomous modules of your brain do. But who knows.”

    The content of experience is almost certainly not epiphenomenal but why isn’t it spread out rather than topologically mapped? Why is experience placed in the full 4D geometry of the world and not in a symbolic processor? I believe that the form of experience is only apparently epiphenomenal because when my own body lacks the form in its brain, during anaesthesia etc., it is useless. The geometrical form of experience clearly has a function and my suggestion is that is required for the global stability of the brain. Well, it obviously is needed for this function but I have no firm idea why.

  39. 39. Arnold Trehub says:

    John: “… a specific form is not needed for the “I” or for activity in retinoid space.”

    Isn’t this another way of asserting the dual-aspect nature of consciousness; i.e., the best we can do from the scientific stance is to find brain mechanisms that generate proper brain *analogs* of salient phenomenal events? We are not justified in asserting the *identity* of events in the brain (3pp) and the form of conscious content (1pp). This is why I propose the investigatory principle of searching for brain events that are analogous to exemplar instances of conscious content. The SMTT experiment, random-dot stereograms, the pendulum illusion, among other relevant experiments, are good examples of this.

  40. 40. John says:

    The Lilac chaser is another good example.

    When you say that consciousness has a dual aspect do you mean that a retinoid system that is implemented in a digital computer would have conscious experience?

    If I analyse conscious experience and compare its form with the form of topological maps in the brain it seems quite possible that the three dimensional part of this form might be instantiated in neurons in the brain. If I compare the form of my experience with a distributed processor that has parts in Rio de Janeiro, Paris and Sydney that are connected by the internet yet performs the same function as my brain then I cannot see any possibility of relating the two. There is no need to be mystical about the connection between experience and brain, they probably do map onto each other but not in 3D.

  41. 41. John says:

    The “Lilac Chaser” is at the bottom of: Why Direct and Naive Realism are unscientific. WordPress blocked my img coding above.

  42. 42. Arnold Trehub says:

    John: “When you say that consciousness has a dual aspect do you mean that a retinoid system that is implemented in a digital computer would have conscious experience?”

    No. A digital super-computer might be able to run a *simulation* of a retinoid system but, by its very design, it can *not implement* a retinoid system. As a matter of fact, I have asked knowledgeable people if they know of any existing artifact that has a volumetric 3D space with a coherent short-term memory and a dynamic component of perspectival origin (I!). So far, no examples have been given. Do you know of such an artifact?

    The “Lilac chaser” example, as such, depends on well-known retinal properties and doesn’t need to be explained by the special structure and dynamics of the retinoid system. What happens in this example is that there is a rotating gap in a ring of lilac-colored discs. The color of the discs “bleaches” the red cones of the retina so that wherever the rotating gap appears, the opposing color cones (green) provide the stronger excitation and we see lilac discs “chasing” a green disc round and round. Of course I would claim that the fact we are *conscious* of these retinal events is explained by the properties of the retinoid system.

  43. 43. John says:

    Arnold, why is the geometrical form of the retinoid system so important when its functional outputs for a given set of inputs could be achieved using other types of processor?

    On the subject of the “lilac chaser” you say: “Of course I would claim that the fact we are *conscious* of these retinal events is explained by the properties of the retinoid system.” I would agree, the afterimage and modelling of motion of the afterimage are in the CNS (the retina being an outgrowth of the CNS). The interesting feature of this illusion is that it is a phi illusion using pure CNS data so contradicts Direct Realism and, given that the illusory motion disappears if the interval between the disappearance of the dots exceeds 0.5 secs, demonstrates the 0.5 secs delay. It is a nice illusion to use in the debate against direct and naive realism.

    I was going to develop an argument from the form of the illusion on the retina to the form in experience and query why the intermediate systems should be devoid of form but this would really just be repeating the question at the start of this post.

  44. 44. Arnold Trehub says:

    John: “Arnold, why is the geometrical form of the retinoid system so important [1] when its functional outputs for a given set of inputs could be achieved using other types of processor?[2]”

    1. Both the spatiotopic organization and the geometrical form of the retinoid system are important to its causal role in consciousness and preconscious cognition. In my theory, consciousness is constituted by the 4D field of autaptic-cell activity within the egocentrically organized Z-planes of the retinoid system (retinoid space). I suspect that you have no question about the spatiotopic organization of retinoid space. Why must we take its geometrical form into account? Consider the geometric form of an electromagnet in relation to the local strength of its magnetic field. If we have an iron core with ten turns of insulated copper wire tightly wound around it and pass a current through the wire at a fixed voltage, we generate a magnetic field with a particular flux density. If ten turns of the copper wire are loosely wound around the iron core, the flux density changes. So the geometric organization of the electromagnet makes a real difference in the physical world. Similarly, in the brain’s Z-plane space the actual physical arrangement of the autaptic cells will affect the intensity and distribution of the 4D electromagnetic field that they generate in the brain.

    I agree that the phi-illusion aspect of the “lilac chaser” is another example of the falsity of direct realism.

    2. What other types of processor can you suggest?

  45. 45. Kar Lee says:

    Vicente, I have been lagging behind for so long in the discussion…. finally there is something I can quickly comment on.

    You say,
    “Actually I believe that one of the goals in life is to kill the zombie……To me, Epiphenomenalism is being an idiot watching what the wimmy autonomous modules of your brain do. But who knows.”

    To me, epiphenomenalism is like watching a movie playing out on the screen (the mind screen?), with the actions of the principal character logically plotted that you finally forget that you are watching a movie and merge (identify) yourself with the character you are watching and take responsibility for the character’s actions. At the end, you also realize that there is no other choices other than the path prescribed in the movie because the movie follows a path in the “physical” realm, which is causally closed to your (the movie viewer’s, not the character’s) intervention.

  46. 46. John says:

    Arnold: “In my theory, consciousness is constituted by the 4D field of autaptic-cell activity within the egocentrically organized Z-planes of the retinoid system (retinoid space)”

    I agree that something very similar to this must be happening to create conscious experience. This is a very specific geometrical and functional organisation that is, in principle, a basis for both the geometrical form of experience and the intervention of the content of conscious experience in behaviour.

    So why am I, in this recent series of posts, dwelling on epiphenomenalism? Epiphenomalism arises because the 3D arrangement of the retinoid system alone is adequate for explaining the functional output of the system but 3D alone is not adequate for linking the system to conscious experience. In fact, although the brain uses a topological method of processing the perceptual field this could also be done using a digital computer with data laid out in linear memory as storage (like using beads on a string) or even using linked lists where the topography of the storage medium would bear no relationship at all to the topography of physical space. So a system that gives the functional output of the retinoid system does not require a specific geometrical form. It just happens that for some reason the brain prefers topologically mapped processors.

    The way that functional outputs are not tied to the form of objects is demonstrated by your electromagnet example. The functional output in your example is a switch from a field of say, 1 tesla, to a field of 1.2 tesla at a particular place.This could be achieved as in your example loosening or tightening the turns on an iron core but it could also be achieved by placing another magnet in the system, by placing a ferromagnetic core near the observer of the field, by placing a magnet of opposite polarity behind the observer etc. It is not until we get to the molecular level of size that functional outputs become tightly linked to form.

    It may simply be the case that topologically mapped processors are convenient for a biological organism. In which case the 3D layout of the retinoid system is just an accident of evolution. Alternatively the topological mapping may be essential because otherwise the organism cannot have conscious experience that involves at least 4 dimensions. However, from the functional viewpoint a 3D organisation or even no topological organisation at all would provide the functions. It seems that the 4D form that gives the retinoid system an egocentric perspective is unnecessary for function. The 3D part of the form of the retinoid IS necessary but not obligatory. The egocentric, 4D, bit is not necessary for function. I say “seems” above because I suspect that the egocentric layout is indeed required but I cannot say for certain why it is needed.

  47. 47. Vicente says:

    Arnold

    Why must we take its geometrical form into account? Consider the geometric form of an electromagnet in relation to the local strength of its magnetic field. If we have an iron core with ten turns of insulated copper wire tightly wound around it and pass a current through the wire at a fixed voltage, we generate a magnetic field with a particular flux density. If ten turns of the copper wire are loosely wound around the iron core, the flux density changes. So the geometric organization of the electromagnet makes a real difference in the physical world.

    Well, not really, you could achieve the same field intensity increment, just increasing the current keeping the same geometry. There is no relevant difference in the physical world.

    This is not the point at all, consciousness is a matter of quality, not quantity. The point would be, that changing the geometry of the wire turns, you create a new kind of force, a different interaction, or that over a threshold number ot turns or current intensity the field appears in an on-off fashion…. which is not the case.

    What you are saying is that maybe by changing the topology of brain neural networks you can change some intellectual capabilities, for example to be able to compare shapes faster, add numbers faster, construct sentences for efficiently etc. But that explains very little about how conscious experience arises.

  48. 48. John says:

    Vicente: “But that explains very little about how conscious experience arises.”

    Topological mappings do correlate with conscious experience. at least in as far as “what is adjacent to what” is concerned. A topological map in Minkowski spacetime (ie: in the natural world) could become an egocentric mapping in 4D. So Arnold seems to me to be right about the need for geometrical form in a neural network that produces conscious experience. The only problem is the hoary old problem of apparent epiphenomenalism of the 4D part of the form (the 3D part is not epiphenomenal but not obligatory either).

    Function is indeed dependent on form at the micro-scale. It is the form of the wavefunction of an electron that fits around a nucleus, it is the form of a molecule that predisposes it to hydrogen bonding etc. This suggests some wild speculations such as the form of conscious experience being related to the form of the wavefunction that is the small part of the brain where the experience resides…

  49. 49. Arnold Trehub says:

    John: “It seems that the 4D form that gives the retinoid system an egocentric perspective is unnecessary for function. The 3D part of the form of the retinoid IS necessary but not obligatory. The egocentric, 4D, bit is not necessary for function. I say “seems” above because I suspect that the egocentric layout is indeed required but I cannot say for certain why it is needed.”

    It seems to me that the “devil” is in the concept of “function”. As far as I can see as a neuroscientist, NO function can happen in zero time. So any function *must* occur in 4D space-time. Am I wrong?

    My claim is that *subjectivity* (having an egocentric perspective) is absolutely necessary for a creature to be conscious. There is no phenomenal world without subjectivity. The function at issue is the function of subjectivity. Creatures without subjectivity (without a retinoid system) adapt to events in the world in a stimulus-response fashion (see Fig. 1, here: http://journalofcosmology.com/Consciousness130.html).
    We might think of this as a lower level of cognition similar to the function of a thermostat, for example. The kind of cognitive function that consciousness enables — having an egocentric perspective in a phenomenal world — is at a much higher evolutionary level of creature adaptation. It is this consciousness-enabled cognition that we now exhibit in our present exchanges.

  50. 50. Arnold Trehub says:

    Vicente: “Well, not really, you could achieve the same field intensity increment, just increasing the current keeping the same geometry.”

    In order to increase the current with the same geometry of the electromagnet you would need to increase the applied voltage. I stipulated a FIXED voltage in my electromagnet example because ionic potentials in the neurons of the retinoid system can NOT exceed physiological limits. With a sufficient change in the geometry of the brain mechanism there will be a change in electromagnetic field potentials that can not be compensated by natural ionic potentials.

  51. 51. Vicente says:

    Arnold,

    That was not my point, and actually I was lying, it is not true that increasing the current is equivalent to adding turns, because the space distribution of current elements is different, and thus the integral, i.e. contributions to the field for each point of space are different. On the solenoid axis the effect is equivalent, due to the symmetry, but nowhere else.

    The equivalent question is: why currents produce magnetic fields? how can the spin, an intrinsic angular momentum exist, and when associated to charge produce a magetic field? quantum electrodynamics take a step forward to answer these questions, but you just have to take another step, and that’s it, lost again.

    The point is that there is nothing new, no difference in the laws of physics,with one or a billion turns. The geometry has no impact on the laws of physics.

    So, why does the topology of the retinoid system, or the maximum membrane voltage, or any other anatomical, histological or physiological parameter helps to create the conscious experience, within the laws of physics, how?

    John, you must be kidding again: Topological mappings do correlate with conscious experience

    Then give me the space time coordinates of each pixel(*) of the conscious image of what you are reading. And tell me in what precise point of the brain, the centre of this X is.

    (*)If conscious images can be represented in terms of pixels, at least small checkered areas.

  52. 52. Vicente says:

    Kar Lee, you could be right. I want to believe that we can also be script writers and directors… with all the constraints impose by circumstances of course, might be just wishful thinking.

    We always get back to the same circular inconsistencies, who is watching what? who merges (identifies) with what? what is the screen of mind? etc

    You know, it is funny. Throughout my life I’ve had to work in different fields and disciplines… and in all of them, studying and knowledge gained with effort and experience, have made me feel that eventually I had a better understanding of each field, more solid, more knowledgeable overall. But with this topic of consciousness it is the other way round, I get more and more confused with time…. well I am just a layman… but pros don’t seem to me to be more clearer as far as I can see… what do you think?

  53. 53. John says:

    Vincente, topological maps do correlate with the content of conscious experience.

    You wrote: “The equivalent question is: why currents produce magnetic fields? how can the spin, an intrinsic angular momentum exist, and when associated to charge produce a magetic field? quantum electrodynamics take a step forward to answer these questions, but you just have to take another step, and that’s it, lost again.

    The point is that there is nothing new, no difference in the laws of physics,with one or a billion turns. The geometry has no impact on the laws of physics. ”

    See Evidence for length contraction: the field of an infinite straight current

  54. 54. kcuhcttenneb says:

    Perhaps this question is too basic for this forum, but something I’ve always wondered about Libet-type experiments is whether they’re just measuring the growing “anxiety” of the test subject about when to trigger the button. I’m a software engineer, and when I imagine myself in the experiment, I’m wired up and I sit there waiting, with a sense of time going by. At some point, there’s some part of me that has a growing sense that there’s been enough time, so I push it. So there’s something akin to a software timer that nags at me until I push the button, and I can’t imagine a scenario where I wouldn’t feel that. Seems like that would correspond in some way with the Readiness Potential.
    One other question–how does the test account for pushing the button rapidly, which anyone could do, multiple times in periods of less than 1/2 second?

    Thanks for your patience with these elementary questions!

    Kcuchtteneb

  55. 55. John says:

    kcuhcttenneb, could you imagine a great debate about the headline:

    “Neuroscientists prove that you cannot know you have taken a decision until you have taken it!”

  56. 56. John says:

    Arnold: “It seems to me that the “devil” is in the concept of “function”. As far as I can see as a neuroscientist, NO function can happen in zero time. So any function *must* occur in 4D space-time. Am I wrong?”

    I agree. Functionalists are Presentists and Presentists must not only explain how anything can happen but also how anything can even exist. On the other hand Four Dimensionalists such as ourselves are left with the problem of how time is observed to actually “pass”. I suspect that “becoming” is a physical phenomenon that is often mistakenly mixed up with “time” because it correlates with the order of events. Physicists should really get stuck in to this problem of time, I suspect that our whole problem with consciousness results from the lack of proper physical explanations of time.

  57. 57. Charles Wolverton says:

    Arnold -

    In the triangle-behind-slit SMTT experiment how much a priori information is the subject given about what is happening in their FOV: that there is a screen with a slit in it and something unspecified happening behind the screen? that there is unspecified movement of an unspecified object behind the screen? that the movement is periodic? horizontal? that the object is a geometric figure? that the figure is a triangle?

  58. 58. Arnold Trehub says:

    Charles, in the SMTT experiment the subject is simply asked to turn the controller to make the top “dot” that is visible to the subject in the slit of the screen go *up and down faster or slower*. NO OTHER INFORMATION IS GIVEN. Later analysis of the data show that when the rate of horizontal oscillation of the hidden triangle is ~= 2 cycles/sec (250 ms autaptic-cell refresh interval) a complete triangle is suddenly seen instead of the two “dots” on the vertical visual meridian (the actual retinal stimulus).

  59. 59. Charles Wolverton says:

    Arnold: It seems to me that the “devil” is in the concept of “function”.

    Quite so, and a corollary of the point of my comment 23 is that:

    Arnold: “any function *must* occur in 4D space-time.

    is trivially true if the domain of the “function” includes space and time (duh!)

    John’s comment 26 about bits and digital computing devices in response to my comment 23 seems a nonsequitur given that I explicitly addressed “analog comm” functions (I said “language” but should have said “speech”). It seems that John’s complaint may be less with philosophers and neuroscientists in general than with those so young as to conceive of all processing “functions” as necessarily digital. (Geezers like me recall analog computers, processors, etc.)

    And:

    John: “Functionalists are Presentists

    suggests a sense of “function” perhaps more along the lines of “one function of a nail is to hold two boards together” rather than the sense I have in mind – as apparently does Arnold – of a mapping from a space of time-varying inputs to a space of outputs possibly also time-varying.

    To generalize my comment 23, I lean toward viewing us as analog processors with time-varying state that take in time-varying sensory inputs and respond with time-varying outputs (actions), either immediate or latent (ie, stored for future use). That may be wrong on many counts, but one of those counts is not that the time dimension is ignored.

  60. 60. Arnold Trehub says:

    John: “On the other hand Four Dimensionalists such as ourselves are left with the problem of how time is observed to actually ‘pass’.”

    I don’t think we *observe* time passing; we *experience* time passing. If you recall how the short-term memory property of autaptic cells in the retinoid system maintains our *extended present*, I propose that time passes slower or faster depending on the duration of the extended present. Under conditions of extreme cns arousal with high diffuse excitation of autaptic cells in retinoid space, full decay of cell-activation in the extended present — the content of our experience –is delayed and the extended present is stretched out over clock time. This accounts for reports of “time standing still” in cases of sudden accidents or other stressful incidents. With lower diffuse arousal, the clock time of the extended present is shortened and phenomenal time passes more quickly.

  61. 61. John says:

    Charles: “..is trivially true if the domain of the “function” includes space and time (duh!)”

    There are two ideas of space and time. In the classical physical model time is part of a geometrical manifold in which space and time are interdependent in a similar way to how length and breadth are interdependent:

    h^2 = length^2 + breadth^2

    and

    s^2 = length^2 + breadth^2 + depth^2 – (c x time)^2

    Notice that time has a negative sign in from of it so instantaneous forms cannot be simply stacked one on the other to make a succession of events.

    The Alexandrian concept of time is as the index of a succession of 3D forms and not related to space at all.

    When Arnold used “4D spacetime” he was explicitly describing events in a four dimensional geometrical form with a negative time dimension (like the real world).

  62. 62. John says:

    “in from of it” above should have been “in front of it”

  63. 63. Charles Wolverton says:

    Armold:

    OK, then I don’t understand why you describe the results as showing that “the human brain has internal mechanisms that can construct accurate analog representations of the external world.” They certainly are suggestive of some interesting inferential processing, but the “external world” from the subject’s POV comprises only the two dots. And if I understand the experiment correctly (eg, I assume the slit is effectively transparent to the subject), the same phenomenon should result if the dots were merely projected onto a slit-less screen so as to move in the same way. In which case in no straightforward sense would the “external world” include a triangle.

  64. 64. Charles Wolverton says:

    “When Arnold used “4D spacetime” he was explicitly describing events in a four dimensional geometrical form with a negative time dimension (like the real world).”

    John, I have understood all along that when you talk about time, you have the spacetime equations in mind. What I don’t understand is why they are relevant. My understanding is that they are applicable in situations where accounting for relativistic effects is necessary (for example, as in my past life involving fast moving satellites keeping extremely precise time). What I take Arnold to be (and know I am) addressing are issues involving relatively static organisms having experiences that evolve relatively slowly over relatively long time durations. Ie, day-today human experiences subject to no relevant relativistic effects.

    So, Arnold, which is your understanding of the role of time in the topics under consideration here? If it is John’s, perhaps you can take as stab at explaining to me why. On this specific issue, I simply have no idea what point John is making.

  65. 65. Arnold Trehub says:

    Charles,

    You wrote:

    “… I don’t understand why you describe the [SMTT] results as showing that “the human brain has internal mechanisms that can construct accurate analog representations of the external world.”[1] They certainly are suggestive of some interesting inferential processing[2], but the “external world” from the subject’s POV comprises only the two dots. And if I understand the experiment correctly (eg, I assume the slit is effectively transparent to the subject)[3], the same phenomenon should result if the dots were merely projected onto a slit-less screen so as to move in the same way.[4]

    1. I say this because when the subject was asked to adjust the rate of oscillation of the “hallucinated” triangle so that its base equalled its height as the height of the occluded triangle was independently varied by the experimenter, the subject was able to do so. In other words, the retinoid mechanism was able to construct a phenomenal representation of a particular kind of triangle as it would appear if presented in the external world. Since no triangle was actually presented, even though it was vividly perceived, I suppose one might call it a hallucination. But notice that it was a hallucination with the visual properties asked for by the experimenter. The subject actually perceived a triangle with its base equal to its height as it would appear in the external world — a proper analog of a real triangle.

    2. I wonder if it would be correct to call this processing “inferential” since the end product is not simply a conceptual classification but a *vivid perceptual experience* –just as vivid as if the moving triangle were an actual stimulus in front of the subject.

    3. From the subject’s POV, initially, there are two dots, but at the critical oscillation threshold from the subject’s POV there is a complete triangle moving back and forth in horizontal motion. When the triangle suddenly appears, the slit becomes transparent to the subject.

    4. I haven’t tried it without an occluding screen. I suspect that if there is no visible occluding contour, the phenomenon might not occur.

  66. 66. John says:

    Charles: “John, I have understood all along that when you talk about time, you have the spacetime equations in mind. What I don’t understand is why they are relevant. My understanding is that they are applicable in situations where accounting for relativistic effects is necessary ”

    These equations are essential to an understanding of “relativistic” effects such as magnetic fields, kinetic energy and dynamics. However, the linear approximations that we call Newtonian physics are also descriptions of four dimensional spacetime, people forget this fact because these approximations are taught as if they apply to a universe that is a simple succession of 3D forms but they are truly approximations to a 4D universe.

    You seem to be saying that the approximations are adequate for all biological investigations. Are these linear approximations appropriate for all investigations in biology? Certainly investigations of most dynamical properties can be easily and accurately described by the approximations. In biology, it is only when we stray into events at the nano-scale and considerations of geometry that the approximations may not apply. In the case of geometry, the Newtonian approximations are DYNAMICAL equations and so are not even applicable to many geometrical questions.

    Our minds are geometrical forms. Just look. We are not going to describe the form of this “view” using dynamical equations, not even relativistic dynamics. The view is a form, not a motion of material objects. If we use geometrical equations to describe the form we discover that it conforms to a simple four dimensional manifold with one negative dimension. Surprise, surprise, this is the known geometrical form of our universe.

    The real problem here is that elementary physics teaches us that all events have a dynamical origin: elementary physics is functionalist. The physics of the past century has blown this away. The study of QM entanglement demonstrates that two distant points can spring into existence with preset properties and this is just the most persuasive of many observations that suggest that we live in a multiverse in which a measurement can give rise to a complete, consistent, classical 4D universe. The past is a fixed, 4D block universe with a peculiar geometry and causality is actually the operation of decoherence – all events look causal but all outcomes can happen, its just that only one happens in our own “classical”, 4D history. The 4D block universe is actually a geometrical form and dynamics is an illusion.

  67. 67. Arnold Trehub says:

    Charles: “So, Arnold, which is your understanding of the role of time in the topics under consideration here?”

    My objective is to understand consciousness and cognition as natural biophysical events. I am agnostic about the ultimate nature of time in the universe we live in. As a neuroscientist, without John’s understanding of current models in theoretical physics, I think the notion of space-time makes sense. But I am most interested in the brain MECHANISMS having neuronal components that can be demonstrated to generate biophysical events that are analogs of salient conscious content.

    I expressed my overview of ALL scientific theory in the book, *What Is Your Dangerous Idea?* (Harper Collins 2007). Here’s what I wrote on
    page 234:

    “The entire conceptual edifice of modern science is a product of biology. Even the most basic and profound ideas of science — think relativity, quantum theory, the theory of evolution by natural selection — are generated and necessarily limited by the particular capacities of our human biology. This implies that the content and scope of scientific knowledge is not open-ended.”

    Would you agree?

  68. 68. Charles Wolverton says:

    Arnold:

    I referred to the processing as “inferential” because if you exclude some vision physiology-based phenomenon like phi-illusions, the brain has to construct the triangle logically using whatever information can be gleaned from the appearance of the test setup and the behavior of the dots. But I’m open to an alternative term.

    For example, if the subject is aware of the slit (which from your reply I gather is the case) and is familiar with focal-plane shutters in cameras, it might be natural to interpret the relative motion of background and slit as the latter moving across the former rather than vice versa. Then “seeing” (ie, reconstructing) the figure displayed on the computer screen would be, in that sense, “taking a photograph” of that figure. The oscillation of the reconstructed figure could be the result of the brain compensating for the actual motion being of the background rather than of the “focal-plane shutter”

    Alternatively, the processing might involve the subject’s assuming (why isn’t at all clear to me) that there is some figure oscillating behind the screen and trying to reconstruct it based on estimates of the characteristics of the motion of the upper dot (eg, constant speed in both directions, equal or unequal, etc).

    It seems to me that the subject must infer something about the background in order for any image to be constructed. Otherwise, why would two dots on a field, one of which simply moving up and down above the other, cause any 2D figure to be constructed?

    This suggests several possible extensions of the test:

    1. The one suggested in my previous comment. My understanding is that we in some sense “complete” occluded surfaces, so I’m with you in suspecting that in the absence of a visible slit – ie, of any implication of an occluding entity – there will be no completion, ie, no figure reconstructed.

    2. Extension 1, but tell the subject (untruthfully) that there is a figure moving behind the screen and the dots are being seen through a slit.

    3. Use different figures, in particular more complex ones. Failure to produce corresponding mental images might exclude the “focal-plane shutter” idea. If images are produced, try moving the slit along different axes – vertical, angled.

    4. Try it with young subjects. If my hypothesis of “inferential processing” were correct, they would have fewer concepts with which to work in producing the images.

  69. 69. Arnold Trehub says:

    Charles: “I referred to the processing as “inferential” because if you exclude some vision physiology-based phenomenon like phi-illusions, the brain has to construct the triangle logically using whatever information can be gleaned from the appearance of the test setup and the behavior of the dots. But I’m open to an alternative term.”

    An “inferential” process is a *logical* process based on propositional structures. The processing in the brain’s retinoid system that constructs the moving triangle is based on the processing of neuronal *images* in retinoid space. This processing of phenomenal experience is not inferential, but is predictable from the neuronal structure and dynamics of mechanisms in the retinoid system. An account of the relevant operational details of the retinoid mechanisms is given on pp. 228-230 in *The Cognitive Brain*, here:

    http://people.umass.edu/trehub/thecognitivebrain/chapter14.pdf

    Charles: “Use different figures, in particular more complex ones. Failure to produce corresponding mental images might exclude the “focal-plane shutter” idea. If images are produced, try moving the slit along different axes – vertical, angled.”

    Many different kinds of complex figures have been used, including drawings of animals, faces, complex objects, etc. The results are the same as predicted by the properties of the retinoid system — subjects experience a complete figure when only tiny fragments of the figure are provided as input to the foveal meridian. When the slit is angled, the whole figure is perceived as angled even though the figure behind the occluding screen is *not* angled. This too, follows from the neuronal structure and dynamics of the retinoid mechanisms.

    Charles: “Try it with young subjects. If my hypothesis of “inferential processing” were correct, they would have fewer concepts with which to work in producing the images.”

    It has been tried with all kinds of subjects, younger and older. The SMTT phenomenon occurs with subjects having meager conceptual resources. It seems to be just a natural consequence of the properties of the brain’ retinoid system. It supports my claim that activity in retinoid space constitutes consciousness.

  70. 70. Kar Lee says:

    Vicente,
    In the past, there were several times I came to the conclusion that this world could not possibly be real because of the absurdities one often got himself into. But then the reality always fought back and I was always brought back into the “reality”.

    Looks like there is definitely a “movie” going on (some called it the external world). And then there is a watcher: you. But the movie is so real that you think you are inside the movie. You think you “will” the action of the character you are watching. But the movie provides enough hint that what you “will” is something that has been given to you instead of generated by yourself, so that the movie can go on and plays out consistently. I may think that I am the author of these words in this posting. But the fact is, anyone with a brain identical to mine would sit down and type out the same words, which is what the movie script would have it anyway. I think for the movie watcher to be able to come to this conclusion, and at times able to realize that he is just watching a movie, before the movie drags him back into the “reality” is already a huge advance, compare with the era when all the watchers simply took the movie as the reality.

  71. 71. Charles Wolverton says:

    Arnold -

    That’s interesting and seems to suggest that the mechanism, whether implemented per your retinoid system concept or otherwise, is somewhat analogous to a focal-plane shutter. I find this a surprising idea, but that means nothing since I’m almost perfectly ignorant of visual sensory input processing and therefore singularly unequipped to speculate on how processing of inputs from the visual FOV might be implemented in the brain.

    In any event, if that analogy applies, I agree that “inferential” is an inappropriate descriptor of the process leading to reproduction of the occluded figure in the subject’s visual phenomenal experience (by which I mean the apparent “mental images” consequent to processing visual input data). However, I still have problems with claims such as “activity in retinoid space constitutes consciousness”. I can buy a claim something like “activity in retinoid space plays a critical role in the occurrence of visual phenomenal experience”, but I’m not clear on how to interpret “constitutes” in this context (mightn’t it be interpreted so as to violate what I take to be your and Tom’s agreement about the non-identity of neural activity and phenomenal experience?)

    And as always, “consciousness” doesn’t seem to me sufficiently well-defined to render claims about what it is, or does, etc, meaningful. For example, if one assumed requirement of being “conscious” is the ability to recognize a figure in phenomenal experience (whether reconstructed from partial data collected over time ala SMTT-type experiments or not) as a specific figure (eg, as a “triangle”), then more much than the occurrence of the phenomenal experience is required to “constitute consciousness” – at least if one accepts Sellars’ challenge to the “myth of the given”.

    One can, of course, choose to define “consciousness” as including or excluding any particular feature, but that degree of flexibility in the use of a word would seem to render the word meaningless for any concept of “meaning” with which I’m familiar. (Which is pretty much how I see the current state of affairs for “consciousness”.)

  72. 72. Charles Wolverton says:

    PS to Arnold re comment 67:

    Yes, I agree with the essence of the comment.

  73. 73. Vicente says:

    Charles,

    then more much than the occurrence of the phenomenal experience is required to “constitute consciousness”

    Yes, that is why I have always understood that we have to make clear the difference between just consciousness and awareness , or conscious awareness. To me, the key is in the concepts of “meaning” and “understanding”, always so slippery.

    I agree with you, that language is definitely not helping much to solve the conundrum.

  74. 74. John says:

    Charles: “And as always, “consciousness” doesn’t seem to me sufficiently well-defined to render claims about what it is, or does, etc, meaningful.”

    This is why we should stick to currently unexplained phenomena such as conscious experience. If we could even explain the form of the experience containing this screen it would be a giant step forward.

  75. 75. Arnold Trehub says:

    Charles: “However, I still have problems with claims such as ‘activity in retinoid space constitutes consciousness’. I can buy a claim something like ‘activity in retinoid space plays a critical role in the occurrence of visual phenomenal experience’, but I’m not clear on how to interpret ‘constitutes’ in this context (mightn’t it be interpreted so as to violate what I take to be your and Tom’s agreement about the non-identity of neural activity and phenomenal experience?)”

    I have used the term “constitute” after some deliberation. I use it in the dictionary sense of “to form” or “to make up” something (consciousness). My claim is that supra-threshold autaptic-cell activity within the Z-planes of retinoid space is NECESSARY AND SUFFICIENT for consciousness to exist. If this is the case then I think it proper to say that activity in retinoid space *constitutes* consciousness. Of course you might disagree with this claim, and the burden is on me to provide evidence. Also, I would argue that my claim does *not* violate our agreement about the non-identity of neural activity and phenomenal experience. In order to assert the logical identity between brain events (3pp) and phenomenal events (1pp), both classes of events would have to have a common domain of description. Referents outside of your own brain (3pp) are described in different terms than referents that are inside of your own brain (1pp). In this case there can be no corresponding logical *identities*, but there can be *corresponding analogs*.

    Charles: “And as always, ‘consciousness’ doesn’t seem to me sufficiently well-defined to render claims about what it is, or does, etc, meaningful. For example, if one assumed requirement of being “conscious” is the ability to recognize a figure in phenomenal experience (whether reconstructed from partial data collected over time ala SMTT-type experiments or not) as a specific figure (eg, as a “triangle”), then more much than the occurrence of the phenomenal experience is required to ‘constitute consciousness’ – at least if one accepts Sellars’ challenge to the ‘myth of the given.”

    I have argued that ALL instances of consciousness have a common feature. That is *a sense of something somewhere in relation to oneself*.
    Without this fundamental egocentric sense of being at the origin of a volumetric space (subjectivity) there is no phenomenal experience — unconsciousness. The structure and dynamics of the retinoid system provide a biological substrate for subjectivity/consciousness. I believe that the evidence for this claim is very strong.

    Charles: “One can, of course, choose to define ‘consciousness’ as including or excluding any particular feature, but that degree of flexibility in the use of a word would seem to render the word meaningless for any concept of ‘meaning’ with which I’m familiar. (Which is pretty much how I see the current state of affairs for ‘consciousness’.)”

    If one adopts what I think is a reasonable definition of consciousness (see above) then there is no room for the kind of arbitrary flexibility that would impede a scientific exploration of consciousness.

  76. 76. Tom Clark says:

    Arnold writes in #75:

    “I have used the term “constitute” after some deliberation. I use it in the dictionary sense of “to form” or “to make up” something (consciousness). My claim is that supra-threshold autaptic-cell activity within the Z-planes of retinoid space is NECESSARY AND SUFFICIENT for consciousness to exist. If this is the case then I think it proper to say that activity in retinoid space *constitutes* consciousness. Of course you might disagree with this claim, and the burden is on me to provide evidence. Also, I would argue that my claim does *not* violate our agreement about the non-identity of neural activity and phenomenal experience. In order to assert the logical identity between brain events (3pp) and phenomenal events (1pp), both classes of events would have to have a common domain of description. Referents outside of your own brain (3pp) are described in different terms than referents that are inside of your own brain (1pp). In this case there can be no corresponding logical *identities*, but there can be *corresponding analogs*.”

    Some reflections on this very interesting comment:

    On Arnold’s account, consciousness isn’t caused as an extra, separate thing. It isn’t a further effect, something beyond its constituting physical conditions that we can point to in public space. We don’t see consciousness in public space, only its constituting conditions. This is why it isn’t identical to those conditions.

    My brain events are part of the class of publicly observable events – a domain of description – described in physical, non-qualitative terms such as quantities, location, motion, etc. This is the public objective 3rd person world, available to all.

    My phenomenal events (my conscious experiences) constitute the class of privately undergone events – a domain of description – described via qualitative terms (red, painful, sweet, etc.). This is the private subjective 1st person world, available only to me.

    So the physical and phenomenal constitute two different domains of description that pick out types of events that can be correlated but not identified. The question is, why is it that we have these two domains, and how are they related? I take a representationalist stab at this at http://www.naturalism.org/appearance.htm

    I’m not sure that the contrast between “referents outside of your own brain” and “referents inside of your own brain” lines up with the contrast between physical and phenomenal domains of description, since the inside brain/outside brain distinction is captured within the domain of physical descriptions. Phenomenal descriptions of experience refer to phenomenal events, not brain events.

    Of course experience itself is our own categorically private, subjectively available model of the *world outside the brain*, hence the fact that when describing my experience of tasting an apple as sweet, I’m also describing characteristics of the apple as captured by my experience. The apple is also describable in strictly physical, non-qualitative terms as well.

  77. 77. Arnold Trehub says:

    Tom: “I’m not sure that the contrast between “referents outside of your own brain” and “referents inside of your own brain” lines up with the contrast between physical and phenomenal domains of description, since the inside brain/outside brain distinction is captured within the domain of physical descriptions. Phenomenal descriptions of experience refer to phenomenal events, not brain events.”

    The meaning I intended to convey was this: The referents of *your* descriptions of *your* phenomenal experience (1pp) are indeed “referents inside of your own brain” because they are *constituted* by the activity within your brain, BUT these 1pp referents are *described* by you in *qualitative* terms (as you say) such as sweet, painful, red, loud, etc., instead of in terms of the neuronal activation patterns in your own brain (3pp). All of your brain activities, as biophysical events, are completely transparent to you at the same time that your phenomenal experience is opaque to you. I don’t think we are in disagreement here.

  78. 78. Tom Clark says:

    Thanks Arnold (77). When I describe an experience I have in qualitative terms, I am referring to that experience – so the experience is the referent. You say that since my experiences are constituted by my brain events that these events are being referred to by my qualitative descriptions, so we have two different descriptions of the same thing, namely brain events. But they aren’t the same thing since according to your two domains of description account, experiences aren’t identical to brain events.

    This suggests to me that the physical-phenomenal relation of being “constituted by” is problematic. It isn’t as if experience is literally built up from physical constituents, or literally consists of physical constituents. If that were the case, we’d see experience in public space, and we don’t. I think we can safely talk about correlations between these different domains of description, but constitution, I’m not sure.

  79. 79. John says:

    Tom: “You say that since my experiences are constituted by my brain events that these events are being referred to by my qualitative descriptions, so we have two different descriptions of the same thing, namely brain events. But they aren’t the same thing since according to your two domains of description account, experiences aren’t identical to brain events. ”

    It seems to me that what Arnold is doing is like referring to slices of salami and saying that they are the same as the whole salami sausage and then using the words “dual aspect” to describe this mistaken identification. We have instruments that measure 3D slices of a 4D reality and then we either confuse the slices with the whole or, more commonly, use the mismatch between the parts and the whole to declare that reality cannot exist.

    Charles gave a good example of this approach when he argued that because we only measure events in the brain in one frame of reference we can just ignore the geometrical form of the world. I would agree with him if measurement and dynamics were the only issues but that is not the case. I cannot explain the geometrical form of the view containing this screen using three dimensional geometry. In fact all of my conscious experience, like the view containing this screen, appears to be at least four dimensional.

    Tom said: “It isn’t as if experience is literally built up from physical constituents, or literally consists of physical constituents. If that were the case, we’d see experience in public space, and we don’t. I think we can safely talk about correlations between these different domains of description, but constitution, I’m not sure.”

    Well Tom, experience could be built up from physical constituents that combine to form a point in public space (Arnold’s first person perspective). In fact successions of events in the real world naturally combine in this way – it is only events on the surface of a light cone that can be observed at any instant and the events on this surface are also at a point, the apex of the cone.

  80. 80. Arnold Trehub says:

    Tom: “When I describe an experience I have in qualitative terms, I am referring to that experience – so the experience is the referent.”

    Yes, but the experience you call the “referent” is constituted by a particular pattern of brain activity. I make a distinction between the words expressed in public sentential descriptions and the brain REFERENTS of these same words. If, for example, you say “I see a *red* ball”, in common language you are *talking about/referring to* a ball having the quality *red*. You implicitly assume that others will understand *your kind of color quality* picked out by the word “red”. But, according to the retinoid theory of subjectivity, your quality *red* is *constituted* by a particular pattern of neuronal activity in your retinoid space. This personal pattern of brain activity is the particular biophysical referent that justifies your saying “I see a *red* ball.”

    I’m trying to come to grips with the problem by thinking about it this way:

    1. Some descriptions are made public.

    2. Some descriptions remain private.

    3. All scientific descriptions are public.

    4. Phenomenal experience (1pp) is *constituted* by brain activity (3pp).

    5. All descriptions are selectively mapped to egocentric patterns of brain activity in the producer of a description and in the consumer of a description.

    6. The egocentric pattern of brain activity — the phenomenal experience — to which a word or image in any description is mapped is the *referent* of that word or image.

    7. But phenomenal experience cannot be reduced in description to the egocentric brain activity by which it is constituted (there can be no identity established in description) because there is always a gap between a description and its referents.

    8. It seems to me that this state of affairs is properly captured by the metaphysical stance of dual-aspect monism.

    Does this make sense?

  81. 81. John says:

    Dual Aspect Monism mystifies the obvious:

    1. Measurements allow us to represent the world in a 3 dimensional manifold. People have seen 3D models from a first person perspective but no-one has ever been a 3D model! Three dimensional manifolds are a simplification of reality.

    2. We see things in a first person, at least four dimensional, manifold of events. Look around folks, there it is. It is your experience. It seems like a point observation but it has stuff distributed in space and time as well. Arnold calls it an “egocentric” perspective.

    Arnold and Charles will both declare that the three dimensional manifold is “reality” and experience is something else or perhaps does not even exist because it cannot be explained by three dimensional “reality”. The truth is actually well known to be the opposite, isolated 3D forms are abstract entities and the universe is more complicated than 3D. In fact it is far more like our egocentric manifold than a succession of 3D states.

    The first person perspective is composed of vectors (directed elements) that are pointed at a centre point of a sphere, the vectors have no net length (null vectors). These vectors are very reminiscent of the paths of photons – virtual or real photons. Seek them in a small region of the brain, probably in the thalamus. OK, experience will not be directly in the neurons, it will be in the field that surrounds them, but it will be a physical form in a physical substrate. It will be possible to measure the 3D form of this field but a simple mathematical transform will be needed to convert these measurements so that they describe the form that is our experience. The need for such a transform does not prove “dual aspect monism”, it just shows that our measuring devices can only probe 3D slices of reality at the moment.

  82. 82. Charles Wolverton says:

    Charles will … declare that the three dimensional manifold is “reality”

    Being a Rortian, I would of course do no such thing, “reality” being one of many words I eschew in serious conversation.

    You have recently attributed to me several positions that I don’t even recognize, never mind subscribe to. The polite way to handle such matters is to state a position and ask if someone agrees.

  83. 83. Arnold Trehub says:

    John: “Dual Aspect Monism mystifies the obvious:”

    The characterization of 4D space-time might be “obvious” to someone like yourself, schooled in modern physics and committed to your particular view of the universe, but its implications are not generally obvious. The same is the case with the notion of dual-aspect monism. Neither formulation, however, is free of mystery. As science and metaphysics answer a question, the event that is demystified usually begs another question. The domain of mystery might shift, but mystery always remains.

    John: “Arnold and Charles will both declare that the three dimensional manifold is “reality” and experience is something else or perhaps does not even exist because it cannot be explained by three dimensional “reality”.”

    Speaking for myself, I don’t think your characterization is accurate. I believe that there is a 4D space-time reality, and that phenomenal experience *does exist* in the 4D manifold as activity in a particular kind of biophysical mechanism (the brain’s egocentric space within the retinoid system). However, even though this is my belief/theory, I cannot *prove* it. So I cannot claim that I speak the TRUTH. The best I can do is to provide evidence in support of my theory. All scientists are subject to the same limitation.

    John: “Three dimensional manifolds are a simplification of reality.”

    I agree. Science is a pragmatic enterprise that progresses as its simplifications of reality — its theoretical models — are able to explain and predict relevant empirical findings.

  84. 84. John says:

    Charles: “The polite way to handle such matters is to state a position and ask if someone agrees.”

    My apologies. You seemed to say earlier that simple physics is sufficient to explain brain activity. The point that I am making, and I think Arnold is making in a different way, is that brain activity is insufficient to explain experience, it is also necessary to consider the overall form of brain activity. This does not mean proposing that neurones go flying off at relativistic speeds and affect the physics of the brain but examining some of the fields in the brain that do move outside of the normal frame of reference of the brain (such as electric and magnetic fields) and also considering the paths taken by virtual/real photons because these paths exist even when there are no photons to traverse them.

    Consider a photon (an electric field carrier) going between two points in the brain. The photon travels along a path which, if you could travel along it, takes no time to traverse and has no length at all. If an entity were a field of photons it would be a small world indeed. But it is the paths in spacetime that have no length and no temporal displacement, a photon just happens to use these paths. This means that even if the photons are removed there are places joined by the paths that might be used by photons in the four dimensional brain that are very close to each other.
    Do you disagree?

  85. 85. Charles Wolverton says:

    Reply to Arnold’s 80 (with aside to Tom at the end):

    1. Some descriptions are made public.

    2. Some descriptions remain private.

    I’ve been going round and round about these seemingly straightforward premises, thought I had a grasp on them, and now am more confused than ever. Here are the problems I see.

    A description per premise 1 presumably is “public” in the sense that it is assumed to be based on observation of a publicly accessible object or event. But there are (at least) two possible ways that such a description might be effected. The obvious way is that it is really a description of the observer’s phenomenal experience when viewing (assume visual observations) the object or event. But then it seems that the description is actually private, assuming that in the case of premise 2 a description is based on observation of an event that is accessible only by the observer.

    Another way that a description of a publicly accessible object might be effected is directly based on the neural activity attendant to observing the object or event without involvement of the associated phenomenal experience, which then becomes in some sense an a posteriori reporting function. That’s the way I understand Tom to be championing, and I am quite receptive to the possibility that he is correct. (That seems one possible interpretation of the Libet et al experiments.)

    Just to avoid any additional ambiguity, I assume we all agree that however descriptions are effected, they are expressed in a “public” language.

    3. All scientific descriptions are public.

    Even with the clarification that “are public” means “are of publicly accessible events”, I find the premise problematic since it embodies the (IMO, unjustified) assumption that “3pp/public” descriptions are “objective”, presumably meaning inherently credible (or at least more credible), whereas “1pp/private” descriptions are “subjective”, presumably meaning inherently incredible (or at least less credible).

    I understand scientific investigation to be credible is not because it produces only premise 1-type (public) descriptions but because the process of producing scientific descriptions is characterized by:

    - the redundancy of multiple independent descriptions of objects or events of a defined type, whether multiple descriptions of the same (or equivalent) publicly accessible object or event, or multiple descriptions of the same type of privately accessible event.

    - a common, reasonably precise vocabulary that most members of a specific scientific community adhere to most of the time

    - an assumed normativity within the community that constrains the descriptive behavior of its members; eg, having actual expertise in the topic under discussion; appropriately structuring experiments; no fudging data, plagiarizing, compromising for gain, etc. I take this to be analogous to Davidson’s “Principle of Charity” re language speakers in general, viz, the assumption that in order for communication to proceed at all, speakers must mostly use language in accordance with certain implicit norms.

    - a flexibility that allows correction of positions that are assessed as inconsistent with new evidence

    If this is correct, I don’t see that restricting scientific descriptions to publicly accessible events is required since credibility would then be a function of various factors, and although observational perspective would be one of them it would not be privileged. Also, there can be factors like those listed above for public descriptions that enhance the credibility of private descriptions (eg, specialized training ala Sellars’ “Myth of the Given”, Chap XV). So, it would seem that depending on the specific circumstances, either a public or a private description can be the more credible. (Consider the credibility of public descriptions by members of a community with a partisan political agenda.)

    4. Phenomenal experience (1pp) is *constituted* by brain activity (3pp).

    I’ll grudgingly assent to “constituted”, but I think I now have a clearer idea of why I don’t care for the 1pp-3pp distinction (a distinction to which I think John also objects – right, John? ;-) ). Should it turn out that public descriptions are observation reports of one’s perceptual experience, they are really just a special case of private descriptions, which would seem to render the “3pp-1pp” distinction irrelevant.

    I don’t disagree with premises 5 and 6, but neither do I understand their relevance nor see why describing communication that way is useful.

    7. But phenomenal experience cannot be reduced in description to the egocentric brain activity by which it is constituted

    If you accept my translation of this into:

    7′. The vocabulary used to describe phenomenal experience and the vocabulary used to describe associated neural activity are not reducible or translatable one to the other.”

    then I agree – and interpret Tom’s position re “explanatory spaces” as being essentially the same idea.

    But at this point, I diverge from Arnold and Tom who from 7′ draw conclusions about ontology and/or consciousness and/or other deep matters. Following Ramberg and Rorty, I draw the not-at-all deep conclusion that vocabularies arise to meet the specific requirements of a specific topic, so the vocabularies appropriate to different topics are typically – drum roll – different. And there seems little more to say except that any two such different vocabularies are irreducible one to the other since otherwise there would be no need to complicate matters by having both. (There actually is more to be said – and is said at length in the Ramberg essay – though I think it’s a bit afield from the present discussion.)

    In particular, Tom – you might want to try Donald Davidson’s “3 Varieties of Knowledge” (my knowledge of my mind, of your mind, and of the shared world) which develops the idea of “triangulation”, a primitive, incomplete, and not necessarily accurate summary of which I have offered here from time to time. I have only recently attacked the essay itself (previously encountered only indirectly) and to the limited extent that I “get it” (like Sellars, DD is notoriously difficult), it appears to me inconsistent with some of your conclusions. The essay appears in several Davidson collections, in particular the volume titled “Subjective, Objective, Intersubjective”. A bootleg copy (possibly illegal and therefore subject to removal, altho it’s been there over two years so far) is at:

    http://kvond.wordpress.com/2008/10/08/davidsons-three-varieties-of-knowledge/

  86. 86. Charles Wolverton says:

    John (84):

    Being a satcom system engineer by trade, I am used to thinking about complex systems in terms of different levels of integration and different functionality at each of those levels. I find that experience applicable in this arena in that I am consequently quite familiar with the concept of the untranslatability/irreducibility of the descriptive vocabularies appropriate to each of those different levels and am not inclined to read very much into differences in vocabularies that arise for quite different purposes, as suggested in my previous comment. It is quite clear to me that notwithstanding the fact that the molecular properties of materials used to fabricate parts in satellite subassemblies are critical to some aspects of system performance, it would be quite unproductive to try to discuss most high level system performance requirements in terms of those molecular properties. Similarly, I see no reason to try to discuss the high level issue of how organisms learn languages – the level at which I have to function due to my limitations – in terms of how relativity effects influence the behavior of ions in permeating cell membranes. Even so, I might consider that I was overlooking something important were it not that in all the reading I’ve done over the last few years of works by many of the acknowledged greats in the area, neither have any of them considered it necessary to do so.

  87. 87. John says:

    Charles: “Even so, I might consider that I was overlooking something important were it not that in all the reading I’ve done over the last few years of works by many of the acknowledged greats in the area, neither have any of them considered it necessary to do so.”

    The truly greats in the field of philosophy of mind have all taken the approach of describing their experience and then trying to develop a theory from this empirical knowledge. In doing so they usually end up pointing out that it is the form of conscious experience that is crucial.

    Take the following philosophers: Aristotle concludes that mind is a phenomena involving the preservation of separateness in a point, Descartes declares that experience is like stuff laid out on the pineal but viewed from a point that of necessity must be supernatural, Leibniz is forced to conclude that experience converges at a point, Whitehead surveys the thinking of contemporary philosophers and points out that they have no idea of nature and ignore its form becuase they are ignorant. (You could add Plato, Reid, Malebranche, Berkeley, even early Wittgenstein and many more to the list of those who have focussed on “form” rather than, or as well as, function).

    As for great physicists, Weyl says that only conscious entities appreciate the passing of time in a 4D manifold, EInstein says that death is unreal in a 4D universe, Eddington thinks similarly.

    I am not surprised that you missed the way that the “greats” in the field always consider both form and function and conclude that it is the form of conscious experience that is the mystery. Anyone reading a modern journal on the philosophy of mind would also be oblivious to this fact. The problem is exacerbated nowadays because neuroscientists are technicians who make their reputations from pointing kit at brains and correlating results and the great polymath philosophers seem to have died out in the last century.

  88. 88. Arnold Trehub says:

    John: “I am not surprised that you [Charles] missed the way that the “greats” in the field always consider both form and function and conclude that it is the form of conscious experience that is the mystery. Anyone reading a modern journal on the philosophy of mind would also be oblivious to this fact.”

    This is why the SMTT experiment is so important. It gives us compelling evidence that the brain’s retinoid system performs the function of CREATING the FORM of an object moving back and forth, LEFT and RIGHT, in 4D spacetime some distance in FRONT of one’s perspectival “point” of geometric origin, the 0,0,0 retinoid coordinate of the self-locus (I!). The SMTT experiment, which was motivated by the retinoid model, demonstrates how biology creates subjectivity/consciousness.

  89. 89. Vicente says:

    Arnold[88],

    “performs the function of CREATING the FORM”

    this expression could just trigger the same discussion you all had with CONSTITUTES, just replacing consitutes by creates.

  90. 90. John says:

    I agree with Arnold. Our experience is a projective geometrical space and the projection requires at least one extra dimension.

    A new scientific phenomenon involves both form and function. If an observation is a result of a new set of functions then it is just more of the same, perhaps bigger, perhaps swifter or brighter but just more of the same. If the form and function of a phenomenon are new, such as the superposition of electron positions or the layout of a black hole or the “view” containing this screen, then we have a new scientific phenomenon. In this age of computers and the treatment of the brain as an information system, the idea that it might also contain a new phenomenon does not compute. Arnold is prepared to deal with the unexpected but it is surprising how few real scientists are “out there”.

    The egocentric “view” is clearly not a dynamic process in which information about the contents of the view are transferred to a centre point, instead it is just geometry. The centre point is the contents of the view where they are adjacent to each other in four dimensions. The contents of the view are also the same objects separated in space and time. There is nothing in our mind that is not its contents but the separations and “sidedness” of these contents changes depending on whereabouts in the manifold you observe them.

    As an example of how a 4D manifold works, the path to a star that is 4 light years distant and four years in the past is no distance in length, if you probe this path with a spaceship going at almost the speed of light the journey will take no time and the star will be no distance from the earth according to the instruments on the spaceship. If you look down similar paths in the brain that are a nano-lightsecond away and a nanosecond in the past they will also contain objects that are no distance from the observation point. The objects are no net distance along the path from the observation point but they are also spread out in space and time. Reality contains the analogue of fairground mirrors, the same objects have different 4D arrangements at different points.

  91. 91. Tom Clark says:

    Charles (85):

    “In particular, Tom – you might want to try Donald Davidson’s ’3 Varieties of Knowledge’.”

    Many thanks, I will.

    Btw, following up a little on the content of your and Arnold’s posts, I don’t think we’re dealing with public vs. private descriptions, since descriptions are always public. Rather, we’re dealing with two classes of events/objects that get described, one of which is privately undergone (experience), the other of which is publicly observable (physical objects).

    In describing an experience of mine as involving the quality red, I’m referring to that quality as it appears to me, and that appearance can’t be compared to anyone else’s – it’s categorically private. But the description is available intersubjectively and does useful work, since other’s can reproduce in their mind’s eye their experience of red.

    In describing a red ball as red, I’m referring to a characteristic or property of the publicly observable ball in terms of my qualitative experience. But since there is a stable, reliably reproducible set of physical properties that produces what everyone calls their experience of red, red is a useful intersubjective term for describing physical objects. The fact that red as a sensation is privately undergone (never observed in public space) doesn’t detract from its utility in describing public states of affairs. The exact subjective quality doesn’t matter, and doesn’t play a role in third-person descriptions.

  92. 92. Charles Wolverton says:

    Tom: Agreed on all points, especially about the utility of “private” descriptions. (Note that in my long response to Arnold, I try to clarify his use of “public/private descriptions” and explicitly note that in one sense, all descriptions are “public”.)

    John: You might find the following quote from Sellars’ “Empiricism and Phil of Mind” of interest:

    [There] may [be] some place in the total philosophical picture for the statement that there “really are” … particulars [of that specific type] … But this place is not to be found by an analysis of ordinary perceptual discourse, any more than Minkowski 4-D Space-Time worms are an analysis of what we mean when we speak of physical objects in Space and Time.

    Here Sellars is characteristically obscure, but I assume he’s making a point about when use of a specialized vocabulary is appropriate.

    Another well-known Sellars quote is:

    “in the dimension of describing and explaining the world, science is the measure of all things, of what is that it is, and of what is not that it is not” .

    Ie, he appears to be one contemporary (I inadvertently neglected to include that qualification) “great” who not only was well-attuned to modern science but could even be accused of “scientism”.

  93. 93. Arnold Trehub says:

    Tom: “Btw, following up a little on the content of your and Arnold’s posts, I don’t think we’re dealing with public vs. private descriptions, since descriptions are always public.”

    Not so. I’ve produced many descriptions which I discarded in the waste basket before they were made public. I have also produced many descriptions that are now in my filing cabinets and computer memory, Some of these have been made public, some will later be made public, and some will probably never be made public. I suspect that you too have produced descriptions that will never be made public.

    Tom: “In describing a red ball as red, I’m referring to a characteristic or property of the publicly observable ball in terms of my qualitative experience. But since there is a stable, reliably reproducible set of physical properties that produces what everyone calls their experience of red, red is a useful intersubjective term for describing physical objects. The fact that red as a sensation is privately undergone (never observed in public space) doesn’t detract from its utility in describing public states of affairs. The exact subjective quality doesn’t matter, and doesn’t play a role in third-person descriptions.”

    Yes, but the problem we face in arriving at a physical EXPLANATION of subjective experience/consciousness resides in the RELATIONSHIP between the 3rd-person description and the 1st-person description. It is here that I suggest that simple correlation will not do the job, and that it is necessary to apply the principle of corresponding analogs and develop theoretical models that can be demonstrated to generate biophysical analogs of subjective experience (conscious content). In this effort, the structural and dynamic properties of the retinoid model have successfully explained/predicted salient aspects of the SMTT experience. Another successful test of the retinoid model is given by the prediction of the novel pendulum illusion. See *A New Visual Illusion*, p. 239 and Fig. 14.5, here:

    http://people.umass.edu/trehub/thecognitivebrain/chapter14.pdf

  94. 94. Tom Clark says:

    Arnold (93),

    I’m not sure about the distinction between 1st and 3rd person descriptions. Perhaps you could give an example of a 1st and 3rd person description of the same thing, the same referent. When I describe the ball as red, that’s a 3rd person description since it uses a term available to everyone, namely red. We can all observe unambiguously red objects and agree that they are in fact red. This is the case even though the quality red in each observer’s experience is a strictly private, unobservable phenomenon. In saying I have the experience of red, I’m not describing that experience, only naming it; the quality red itself isn’t amenable to description. But I can describe the ball as being red.

    The relationship at issue in the problem of consciousness, seems to me, isn’t between two different descriptions of the same phenomenon, it’s between two prima facie different phenomena, namely qualitative experience and its neural correlates. Although your SMTT experiments establish close parallels (analogs) between the SMTT experience and neural events, the salient aspects of the SMTT experience being correlated with the neural events aren’t qualities (e.g., colors), but shapes. That the conscious content of experiencing a shape would line up with the correlated neural analog of the shape seems unsurprising. What’s puzzling (to me) about consciousness, in trying to understand it scientifically, is that the private, unobservable subjective qualities that make up the experience of shapes exist at all, and the nature of the relationship of those qualities to their publicly observable neural correlates.

  95. 95. Arnold Trehub says:

    Tom (94),

    Thanks for your comments. They expose some of the important traps in trying to come to grips with subjectivity. I’m not sure, but I have the sense that a central problem revolves around an initial stance of *essentialism* vs *pragmatism*. As I see it, there is no level of explanation at which the subjective *essence* of “redness” or “roundness”, or any other quality, can be resolved. On the other hand, as a scientist, I believe that subjective qualities can be usefully understood at a biological level by formulating biophysical models which can successfully generate proper analogs of overt expressions (3rd-person) of covert (1st-person) subjective experience.

    Tom: “Perhaps you could give an example of a 1st and 3rd person description of the same thing, the same referent.”

    Consider your own example of describing a ball as being red. You say:

    “In saying I have the experience of red, I’m not describing that experience, only naming it; the quality red itself isn’t amenable to description.”

    To apply the name “red” to an object is to categorize it and distinguish it from the color quality (in your mind) of other objects. It seems to me that this is a description of your experience. If I were to present you with a green ball, a red ball, and a blue ball, and I point to the red ball and and ask you to name its color, would you claim that you were not describing your impression of the ball you selected? In this case the 1st-person referent is the covert egocentric activation pattern in your brain’s retinoid system, and the 3rd-person referent is your overt verbal expression/description “red”, which I can note, and perhaps qualify you as not being color blind.

    Tom: “The relationship at issue in the problem of consciousness, seems to me, isn’t between two different descriptions of the same phenomenon, it’s between two prima facie different phenomena, namely qualitative experience and its neural correlates.”

    This is precisely what is at issue! You might be justified in claiming that neuronal events in the brain are an essentially different phenomenon than qualitative experience/conscious content. And I might be justified in claiming that certain kinds of neuronal events in the brain are just the 3rd-person aspect of 1st-person qualitative experience — dual-aspect monism. From the scientific standpoint, the significant question to ask is: “What follows from these two different claims.” How do each contribute to our scientific understanding of consciousness?” What empirical evidence can be brought in support or refutation of these opposing views of consciousness?

    Tom: “What’s puzzling (to me) about consciousness, in trying to understand it scientifically, is that the private, unobservable subjective qualities that make up the experience of shapes exist at all …”

    It seems to me that the sheer existence of consciousness is no more puzzling than is the sheer existence of the universe. The sheer existence of anything is a deep mystery. But, of course, if NOTHING existed, and we were privy to this fact, then this too would be a deep mystery! Bottom line, science is a pragmatic enterprise.

  96. 96. Charles Wolverton says:

    Perhaps Arnold is on the right track in 93 by emphasizing “explanation”.

    We can consider a subject’s verbal response to a red ball in his FOV – eg, “That’s a red ball” – to be a description of the content of that FOV, a learned reaction to the neural activity attendant to visual sensory stimulation. Here, “description” is used in the common sense of trying to convey to another the perceived features of the content of the subject’s FOV, in which case it is “1pp” only in the trivial sense that subjects will describe even a publicly accessible scene slightly differently depending on their personal life experiences. Alternatively, we could consider the response to be a description of the associated private (not publicly accessible) phenomenal experience (AKA, “mental image”). But this seems to be using “description” in some other sense, as it’s unclear what is being “described”, from what POV, as seen by who/what.

    In any event, as mentioned before, I think it possible – even likely – that the associated phenomenal experience is only attendant to, but not causal with respect to, the verbal response (a position seemingly consistent with occurrences of blindsight). Then the verbal response would be in no sense a description in the phenomenal experience. (I think Tom agrees with this position.)

    A complete “explanation” of the phenomenon presumably would address the neurological activity patterns behind both the verbal response and the phenomenal experience. And once those patterns has been identified, it seems that in principle they could be separated into those that appear to play a role in causing the verbal mode of reaction, the phenomenal mode of reaction, or both. If they could be independently stimulated, it might be possible to resolve the question of the role of phenomenal experience.

    But whatever the results, what would be seen by the researchers would be publicly accessible neural activity, each “description” of which would raise precisely the same issues. (My point in comment 85, item 2.)

  97. 97. Charles Wolverton says:

    To keep John happy, I’ll amend that last sentence to “publicly accessible evidence of neural activity”, although I suspect everyone else will read the original as meaning that.

  98. 98. Arnold Trehub says:

    Charles: “In any event, as mentioned before, I think it possible – even likely – that the associated phenomenal experience is only attendant to, but not causal with respect to, the verbal response (a position seemingly consistent with occurrences of blindsight). Then the verbal response would be in no sense a description in the phenomenal experience. ”

    I’m puzzled by this statement. As I understand blindsight, the subject denies (verbally) having a visual experience of an event/object, but behavioral tests show a better than chance response to the event/object. Are you attributing to the person with blindsight a conscious visual experience that is nevertheless denied by the afflicted person?

  99. 99. Charles Wolverton says:

    “Are you attributing to the person with blindsight a conscious visual experience that is nevertheless denied by the afflicted person?”

    The phrase “conscious visual experience” is ambiguous and, as best I can tell, hasn’t appeared before in this thread. I’m not sure how to interpret it, so I’ll assume that it is refers to what I call “phenomenal experience”, AKA “mental imaging”. To (tediously) repeat, I think it critical that we adopt a common vocabulary and stick to it if we are ever to reach agreement, or at least mutually understood disagreement.

    My understanding is that in some blindsight experiments, the subject denies having a phenomenal experience consequent to objects or events in his FOV but nonetheless can produce accurate verbal descriptions of them. So, if that’s the essence of your query, the answer is yes.

    That suggests to me that the subject somehow analyzes the sensory input consequent to objects or events in the FOV in such a way as to recognize known objects or events and to be able to produce an accurate verbal description of them despite being unable to generate a corresponding phenomenal experience.

  100. 100. Arnold Trehub says:

    Charles (#99): “The phrase “conscious visual experience” is ambiguous and, as best I can tell, hasn’t appeared before in this thread. I’m not sure how to interpret it, so I’ll assume that it is refers to what I call “phenomenal experience” [1], AKA ‘mental imaging’ [2].”

    1. Yes, a *conscious visual experience* is a particular kind of *phenomenal experience*, namely a *visual* phenomenal experience.

    2. I don’t agree that a *mental image* is necessarily a *phenomenal experience*. In formulating the putative neuronal mechanisms of the cognitive brain, I found it necessary to posit *non-conscious* imaging matrices in all sensory modalities. For example, in the visual modality, see TCB Ch. 3, “Learning, Imagery, Tokens, and Types; The Synaptic Matrix”, pp. 40-44, here:

    http://people.umass.edu/trehub/thecognitivebrain/chapter3.pdf

    If a visual pattern is represented in the imaging matrix of a synaptic matrix but, for some reason, is not back-projected into egocentric retinoid space, it will not be consciously/phenomenally experienced. But even though it is non-consciously experienced it can be cognitively processed and can produce relevant verbal reports or other kinds of appropriate responses. So non-conscious mental images can account for blindsight.

  101. 101. Charles Wolverton says:

    I didn’t mean to equate “phenomenal experience” and “mental image”, just to help identify what I meant by the former. With or without phenomenal experience, it has always seemed clear to me that the ability to recognize objects required something akin to what you are calling “non-conscious imaging”.

    It appears that we are even closer than I thought. Tom and I have each alluded to the processing of sensory input as producing the ability to formulate a behavioral response even if no phenomenal experience occurs. Since neither he nor I are trying to hypothesize an implementation, we don’t need to separate the processing into a part that produces phenomenal experience and a part that doesn’t. But I did speculate on such an architecture here:

    http://www.consciousentities.com/?p=742#comment-166200

    and related it to blindsight.

    Perhaps we are now to the point of going in circles.

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