Private perceptions and public images

Discussion in 'Philosophy' started by billy_mabrey, Dec 28, 2006.

  1. Something I was thinking about while performing surgery on an artist statement:

    Our cameras are devices which recieve and assemble physical information
    (photons)into "public images".

    Our bodies and brains recive and convert physical information (photons,
    pressure/tempurature variations) into "private perceptions".

    Perceptions = images?
    Bodies = cameras?

    The camera is used in an attempt to make a private perception into a public
    perception.
    Is it possible?
    Is there any other purpose to photography?
    Or is this worthless psychobabble?


    Sorry, these are incomplete thoughts.....
     
  2. Go and have a beer - sounds like you need one badly!
     
  3. Interesting question, I think it boils down to this "Can you really ever show anyone exactly what you are seeing?". IMHO perception is everything. And with perception, you are then dealing with one's personal learned associations which are never exact;y like anyone else's.
     
  4. "The camera is used in an attempt to make a private perception into a public perception. Is it possible? Is there any other purpose to photography? Or is this worthless psychobabble?"

    A snapshot, my version of photographic life, in the simple.

    The concept of the "camera," at inception was to aid the painterly artist; camera obscura; light (photo)/writing (graphy). "Tain't no thang."

    The cliches were infused with content in 1915 with Steichen's "Milk Bottles"; Spring, New York, 1915. From the above, you have the advent of the Progressive Humanists, Surrealism; enters Andre Breton, stage right. In the 40's & 50's, Henri Cartier-Bresson enters stage left, breathing life, movement into photography and today, it's up to you and what you want to make of it all.

    Look, it's a cliche (Weston), it's calender art (Galen Rowell); no, it's piss you off time (Andre Serrano); anything you want photography to be; Postmodern.

    "I'll take Neomodernism Alex."
     
  5. There are some remarkable analogies and dis-analogies between camera/ imaging systems and the way bodies and perceptions form useful pictures of this world and alternative worlds.

    The analogy is strongest for digitally based imaging systems and surprisingly weak for film based picture making. Maybe this is why film based photography so often disappoints in the task of turning the picture in the mind into the picture in the hand.

    The human eye is like a digital camera. It has a lens of about 25mm focal length, aperture range approximately f 2.8 to f 11, and is backed with a 100 megapixel fixed array sensor called a retina. Not all the retinal cells are equal in size, sensitivity, or colour discrimination but collectively they form an effective sensor. Strikingly the output from the eye (that is transmitted down the optic nerve) is a series of coded electrochemical pulses of a digital character. The digital camera also turns an image into a coded stream of data, ones and zeros, and stores the result in a memory module, CF card, SD card, or the like.

    The film based camera forms an image just like the eye but effectively does nothing with it; no encoding, no data, no transmission. The image just sits there in the back of the camera until a chemical substance sensitive to the electromagnetic field of the image is introduced. Chemical changes happen and eventually a picture is formed. But the entire sequence happens in the physical world and the possibility of perception as a facet of consciousness does not happen. At least not a this stage.

    The brain as receiver of data from the optic nerve stores that data as neurochemicals and axonic and dendritic interconnections. The data is in code. I have seen numerous brain sections under the microscope, including slices of the optic lobes, and there are definitely no pictures. Imagine for a moment if there were pictures. What implications!

    Stored coded data, either in a SD card (say) or in the brain can be displayed either on a monitor screen (via video software) or in the minds eye by the process of conscious recollection. No hardcopy is needed. The photograph on film conversely exists only as hardcopy, brute matter, that you have to go and fetch everytime you want to look at it.

    Even the production of hardcopy reveals nice parallels. SD card data can be interpreted by software (card reader plus printer-driver) to control the activities of a mark-making engine, say an ink-jet printer to produce a picture. The brain's memory can be used to inform a mark-making engine, say an artist's arm, hand, and brush to make a real picture. The software for this takes about three years to load at art school and it could be referred to as "How to paint."

    Film based pictures never go into code, never enter cyberspace, control nothing. They are what they are, obdurate lumps of matter that can be perceived but cannot constitute perceptions. This gives them their iron grasp on physical reality but closes off the possibilty of picturing imaginative fancies. And the world of things that can be imagined is far richer and often a lot nicer than the world of things that just are.
     
  6. It's like seeing my world and giving my perception to them. They may not look at a photo and see the world I see, or they may look and say," wow, yea I never looked at it in that way". They may read something into the photo that I never realized while taking it. It's always the viewers perception. Different everytime.
     
  7. Yes, it's "worthless psychobabble".
     
  8. The analogy is strongest for digitally based imaging systems and surprisingly weak for film
    Please explain that. I simply do not understand unless you mean that it is more difficult to make pictures with anything but an auto-everything camera. If that's what you mean, then you are ignoring the mastery of the medium, removing the human element.
    The human eye is like a digital camera.
    The eye is not a camera.
    he output from the eye (that is transmitted down the optic nerve) is a series of coded electrochemical pulses of a digital character.
    Not even close. The signals from the eye are thorougly analog, and they are transformed dramatically in various parts of the brain.
    Your analogy is interesting only in its uninformed impressionism.
     
  9. Yes, it's "worthless psychobabble".
    No, it's an artist's statement which is literature, not the art it speaks to, and valuable when understood for what it is.
    OP - keep on it.
     
  10. You're pretty much defining photographic art - the attempt to
    make a public image as close as possible to your private
    perception. It depends on mastering the techniques of taking,
    manipulating and printing the image - whether the result is
    interesting to others or not depends on the originality and
    "added-value" of your private perception (about which much is
    already written).
     
  11. I believe that Ernst Haas said it best, "A picture is the expression of an impression." The rest, in my opinion, is all commentary.
     
  12. Pico,

    Maris is right. The eye and resulting vision is very much like a digital camera both in the way the sensor detects and transmits it's information and the fact that the sensor is not altered. There are analog-like components to the processing in the retina itself (via gap junctions) but the transmission of information to the brain is very much digital in nature, as it is in all neuronal tissue.
     
  13. As for conscious recollection: close your eyes and try to imagine two colors side by side. Say, red and green. Not a very good digital data storage system, is it.
     
  14. "As for conscious recollection: close your eyes and try to imagine two colors side by side. Say, red and green. Not a very good digital data storage system, is it."

    Not a very good analog storage system either.
     
  15. The brain isn't really digital although impulses are sort of digital. There is a whole lot of analog stuff going on in the cells that determine when a cell fires.

    I think the OP's comments are right on the mark. At least I use the camera to capture things that I saw and wanted to make into something to discuss.
     
  16. "The brain isn't really digital although impulses are sort of digital. There is a whole lot of analog stuff going on in the cells that determine when a cell fires."

    Digital electronics also have a great deal of analog modulation as well. The point is that the transmission ('impulses') are by and large 'all-or-nothing'. Don't forget that the gating of many of the ion channels have definite voltage thresholds.
     
  17. Maris is right. The eye and resulting vision is very much like a digital camera both in the way the sensor detects and transmits it's information and the fact that the sensor is not altered. There are analog-like components to the processing in the retina itself (via gap junctions) but the transmission of information to the brain is very much digital in nature, as it is in all neuronal tissue.
    Nonsense. When the paradigm was clay for everything, the mind was likened to clay. When electricity prevailed, it was like electricity. Now it's digital. Bullocks.
    The eye's "sensor" is indeed altered by the light entering it. Study up on that.
    And just because cells, synaps and so forth are discrete does not make the system digital. Some signaling is slow chemical, and some is fast electric (believe it - yes, true electricity, microvolts) and although I am not convinced, it has been posited by some very bright people that some of it is quantum. Quantum is not digital, either.
     
  18. "Nonsense. When the paradigm was clay for everything, the mind was likened to clay. When electricity prevailed, it was like electricity. Now it's digital. Bullocks.

    The eye's "sensor" is indeed altered by the light entering it. Study up on that.

    And just because cells, synaps and so forth are discrete does not make the system digital. Some signaling is slow chemical, and some is fast electric (believe it - yes, true electricity, microvolts) and although I am not convinced, it has been posited by some very bright people that some of it is quantum. Quantum is not digital, either."

    Where do I start on this one! I have studied how the eye works as well as neuronal signalling. I also worked in the field of neuroscience for 10 years measuring the ionic currents of single cells in brain tissue (including human) as well as tissue culture.

    The point about the retinal cells not changing was referring to the fact that they are not permanently changed when exposed to normal light levels. This is very much like a sensor in a digital camera whereas film IS changed permanently. The cells do send out discrete signals which, depending on the cell type, will carry information on the colour and intensity of the light. Put together this will form a complete image after processing in the brain. If you are going to compare the eye, and how it transmits it's information, to anything man-made then a digital camera would be it. The currents may be different (ionic versus electronic) but the actions are the same.
     
  19. If you are going to compare the eye, and how it transmits it's information, to anything man-made then a digital camera would be it.
    It is not helpful to attempt such an analogy. It is far too much of a reach.
    You must understand the fallacy of argument by analogy. It is misleading.
    The retina is analog, as you know. To leap into "it is like a digital camera" because the brain might have a signaling method somewhere that strikes one as "digital" is incautious at best.
    So going back to the top of this thread, I suggest to the OP that he use no such analogy as Perception = images, Bodies = camera.
     
  20. "To leap into "it is like a digital camera" because the brain might have a signaling method somewhere that strikes one as "digital" is incautious at best."

    Might? It is digital in nature Pico. If you've taken any courses at all about neuronal signalling or even action potentials you would know this. Everything from single ion channels to synaptic vesicles are discreet entities.
     
  21. Might? It is digital in nature Pico. If you've taken any courses at all about neuronal signalling or even action potentials you would know this. Everything from single ion channels to synaptic vesicles are discreet entities.
    Synapses work via chemistry to create microvoltage at the location, correct? That just doesn't seem digital to me.
    I can live with this mutual disagreement. No problem.
    However, I'll be a bit of a stickler if someone posits that the brain is a digital computer. :)
     
  22. Pico, you're missing the point, splitting hairs and forgetting that transmission of information (via AP's) is not a continuous function. It's a discrete event that is heavily modulated by many inter and intracellular processes. Most of the modulation, at a basic level, is not only if an AP will be generated but also the frequency of the generation. Even synaptic transmission is a fairly discrete event since the vesicles containing the neurotransmitters are relatively constant in size and will produce a repeatable effect. Have a look at some of the basic research on synaptic transmission and also of single channel recordings - which will give a good graphic represenation of the voltage changes at a very minute level.
     
  23. Andy, if we deconstructed the brain to an absurdly microscopic part and ignore the whole
    it strikes me as oversight, a real stretch. Fairly discrete is not discrete. Digital is binary,
    perfectly discrete. Maybe it is a modestly useful analogy but I don't find it a compelling
    one.

    If we go smaller we can get into microtubules which with the right medium inside might be
    able to sustain quantum interactions.

    How does a single-cell animal interact with its environment if it is not purely chemical,
    analog, and possibly via quantum communication?
     
  24. Digital electronics also have a great deal of analog modulation as well. The point is that the transmission ('impulses') are by and large 'all-or-nothing'. Don't forget that the gating of many of the ion channels have definite voltage thresholds.
    Andy, I don't agree. Digital computers were invented because people wanted computers which give exact answers and work reliably, not subject to analog effects or noise. Thus we now have computers which have two signal levels, 0 and 1. They're distinctly different voltages, this together with discretized time (the system clock) prevents noise from affecting the result of the computation. How is "analog modulation" present in digital electronics?
    In the brain, while some signal transmission is carried out in impulse trains, essentially for the same reason, to enhance reliability, a lot of stuff is carried out by processes which I would have a hard time describing as digital. Yes, there is a threshold, but there are multiple inputs to a cell and the membrane potential is affected by them in various ways. The "addition" is performed in form of ion transfer, and there is a great deal of randomness in this process. Sometimes when you give a person a stimulus, such as an electrical pulse to the median nerve, you get a response in the somatosensory cortex. Sometimes you do not. It's very unlike how a digital computer would process things.
    Unlike the computer, the brain is very flexible. It changes itself in response to external inputs. Its calculations are erroneous. I am sure everyone here will agree that sometimes we just don't calculate correctly. How often do you get a wrong result when using a computer to crunch numbers?
    The analogy between digital technology and the brain is IMO without foundation.
     
  25. Ups, I missed the last two posts. I would like to emphasize that in neurons, the membrane potential fluctuates up and down depending on input, and this is clearly an analog signal. It is trhresholded, yes, and this determines if the impulse is generated, but in a computer the input signals are binary and thresholding a binary input (represented by an analog signal which is one of two voltages) is a quite different thing from thresholding a fluctuating analog signal. If you have two excitatory inputs to a neuron, do you really believe that it just adds them up? Although an ion channel is triggered by a certain threshold voltage level, and it remains open for a precise time, the number of ions that transfer across the membrane during the opening time is not the same every time. And since the membrane potential fluctuates the triggering of a subsequent impulse is definitely determined by an analog process (although you might consider it discrete because ions are discrete units). The number of ions is so large and there is so much variability that the outcome is just not determined by the inputs alone.
     
  26. Unlike the computer, the brain is very flexible. It changes itself in response to external inputs. Its calculations are erroneous.
    There are many computer applications which can adjust themselves, and programs that rewrite themselves. If you want a glimpse, look at Danny Hillis' Patterns on the Stone in which he describe a program that writes programs. It is given a model of the expected outcome, for example a sorted list, and input. It rewrites the code until the outcome is made true for any input. Funny thing, but it even came up with an inscrutible novel technique.
     
  27. Pico, my point is that the brain is changing all the time and this happens at the basic building block level. How many microprocessors change the way they work? Yes, software can be made which changes itself, for sure. But this is not the way computers normally operate.
     
  28. You are speaking of today. Tomorrow will be different.
     
  29. Ilkka,

    You are missing my point entirely which is that the eye is more like a digital camera than film. Not only is it regenerative but also the transfer of the information from the eye to the brain is by action potentials, which are discrete and repeatable. Action potentials are more 'digital' in nature than analog. I also said there was a great deal of modulation which is what you are mainly talking about. But that modulation is concerned with whether an action potential is going to be generated or not and at what frequency. There is also a great deal of modulation in digital electronics.

    As for Pico's discussion on quantum mechanics I'm not sure why that's even being brought up, especially in such large cellular structures as microtubles. To me it just seems like a red herring.
     
  30. You are missing my point entirely which is that the eye is more like a digital camera than film.
    "than film"
    Talk about a strawman. The eye is more like a digital camera than a loaf of bread, too!
    But in reality there are more differences than similarities. The eye is not a camera. The eye is not like a digital sensor. The eye is an eye and a sensor is a sensor.
     
  31. This is probably one of those discussions best avoided...

    I would argue that there are interesting similarities and differences between a biological sensor like the retina and electronic and chemical sensor arrays like CCD's and film, but that arguments about which of the latter two are most like the former are probably unresolvable and beside the point.

    That said, consider the first stage of each:
    Retina involves a destructive, photochemical process (photoisomerization of rhodopsin). This is not "spontaneously" regenerative at the molecular level until the chromophore is chemically regenerated.

    Film involves a destructive, photochemical process. This is never "regenerated" until another sheet of film is put in.

    CCD involves non-destructive production of charge by photon absorption. Regeneration is unnecessary.

    Here I would say the nod goes to film - destructive and photochemical.

    Next, first stage sensor "output":

    Retinal photoreceptor (vertebrates here, inverts can be different) output is strictly analog (neglecting quantized output at low light levels due to guantal nature of light).

    Film is "digital" if I can use the term that way. That is, film silver halide crystals are either converted to metallic silver or not depending upon light absorption.

    CCD individual sensor output is analog. Subsequent analog to digital processing produced the digital signal.

    CCD (e.g. digital camera) gets the nod here - analog sensor output.

    One could argue that the retinal cells prior to the ganglion cell stage, which outputs digital signals to the brain, operate *in part* as A/D converters.

    Really tho' any mention of film versus digital outputs of retinas and CCD's is inappropriate - film is a sensor array with no inherent processing beyond the first stage unlike retinas and digital cameras.

    Finally areguments whether neurobiological systems such as the brain, eye etc are either digital or analog miss the point. Clearly analog components (e.g early sensory processsing) and analog processing (for example the massive dentritic arborizations of cerebellar Purkinje cells are primarily analog signal processors) are essential as are also the digital signals of the nervous system, the action potentials.
     
  32. Andy, where is "modulation" in digital electronics? I don't get it.
     
  33. "...analog processing (for example the massive dentritic arborizations of cerebellar Purkinje cells are primarily analog signal processors) are essential as are also the digital signals of the nervous system, the action potentials"

    = modulation of digital signals
     
  34. "= modulation of digital signals"

    Not really a helpful or even meaningful comment, rather simply a redefinition of terms.

    According to your logic if, in this case, analog processing is simply modulation of digital signals, then just as helpful a redefinition is digital processing = modulation of analog signals.

    Since all first stage sensory output is analog as is also most input to axon hillocks and other sites of action potential initiation (negelcting things like nodes of ranvier which are not relevant) I would argue that if either, digital processing = modulation of analog signals. Really tho', neither restatement adds anything.
     
  35. Andy, you didn't answer my question. Earlier you wrote "Digital electronics also have a great deal of analog modulation as well" (comparing electronics and the brain).

    Where is this analog modulation in digital electronics?
     
  36. Very curious indeed. Analogue is analogue...dgital is digital. There are no two ways about it. The brain operates on chemical transmissions...not digital transmissions. The camera operates on mechanics alone.
     
  37. This has sure strayed from Billy's question at the start of the thread, which han nothing to do with whether or not the brain is analog or digital. When we look at a scene we want to make a photograph that evokes the same feeling as we're experiencing (private perception) as well as just recording it (public image). Is this possible?

    Some photographers are better at evoking feelings than others, but that just begs the question: are they the SAME feelings? I think that it might not matter all that much as long as the viewer gets pleasure from the photograph.
     
  38. Ilka,

    anything circuit using capacitors or inductors could be analog modulation.

    Yes the chemical transmission in the brain is chemical in nature and does not use electrons. However the AP, which is the transmission that I'm referring to is 'digital' in nature. Either it happens or it doesn't. There's no in between. It's the major tranmission source for information along axons. You can delve as deeply as you like into all of the biological systems involved in signalling (such as second messenger systems etc.) but you won't alter the fact of the AP. That's the last I'm going to comment on this. I stand by what I say and nothing is going to sway me, so live with it :p
     
  39. anything circuit using capacitors or inductors could be analog modulation.
    Digital electronics doesn't work that way. The presence of inductors or capacitors is irrelevant. Digital electronics is implemented in such a way that the signal level is always far away from the threshold between 0 and 1. When a signal switches from 0 to 1 or 1 to 0, it happens during a part of the clock cycle which is such that the intermediate values of the signal voltage are not able to affect output. There is no analog modulation unless you're talking about measurement systems which have analog-to-digital converters. But that's at the threshold of analog and digital electronics.
    However the AP, which is the transmission that I'm referring to is 'digital' in nature. Either it happens or it doesn't. There's no in between. It's the major tranmission source for information along axons.
    I don't dispute that neuronal impulses are digital in nature. But the decision whether to fire is determined by complicated biological processes which are NOT digital. This is the key difference: digital signals are only used in the brain for signal transmission. Computations are analog. In digital electronics, computations are digital. They're carried out by logical operations with 0s and 1s.
    You can delve as deeply as you like into all of the biological systems involved in signalling (such as second messenger systems etc.) but you won't alter the fact of the AP. That's the last I'm going to comment on this. I stand by what I say and nothing is going to sway me, so live with it :p
    I recommend that you pick up a book on computer architecture (e.g. the classic by Tanenbaum) and read how computers really work. It's an entertaining read.
     
  40. "I recommend that you pick up a book on computer architecture (e.g. the classic by Tanenbaum) and read how computers really work. It's an entertaining read."

    Did I say anything about computers? You're reading what you want into my comments.
     
  41. And what exactly is the difference between computers and digital electronics, from the point of view of analog modulation? Neither has any of it.
     
  42. (apart from analog-to-digital converters in computers)

    Instead of taking on the excellent Tanenbaum book, if you are impatient you might just read

    http://en.wikipedia.org/wiki/Digital_electronics

    to see whether your views on digital vs. the brain are generally accepted. In fact virtually nothing mentioned on the page about digital electronics can be said about the brain!
     

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