SEEING: an erotic philosophy of visual perception, Supplementary notes
1. About vision (EE from Being about) Ecological optics is less concerned with seeing light than with the seeing of things by means of light James Gibson 1982, 75 The visual system is so important to primates that, in the macaque, visual cortex takes up about half the 100 cm2 extent of each hemisphere (Van Essen 1992, 419). It is very intensively studied, but it is not well understood. This is so partly because its neuroanatomy is complex, but it is a result also of conceptual difficulties that are Cartesian in origin. Gibson is helpful with these difficulties, and the following suggestions are Gibsonian in spirit. 1) We should not think of the eyes as separate sensors. The visual system is a single binocular system, which has two peripheral scanners directed toward an object from slightly different angles. We also should not think of ourselves as seeing with our eyes. We do not see what the eyes would see if they could see: we see by means of our entire visual system. 2) The classical notion of the retinal image is unworkable. There are many subsystems originating at the retina and using different aspects of retinal response, so there would have to be many retinal images. Moreover, imagining a retinal image makes us think of retinal response as punctate, the way a photographic image is composed of grain. There is point-wise response at the retinal surface; rods and cones are very small points of differential response -- to the broad spectrum of visible frequencies of light, or to narrower bandwidths. But response of neural elements connected to rods and cones is already comparative; it is already response to field properties of the array contacted by retinal sheets -- to contrasts and changes in contrast. Further, the neurons correlating points of retinal response are already of different kinds, so they are responding to different kinds of field properties of the optical array. Responses to these field properties are propagated through many matrices, where they are convolved with responses from other matrices. Trying to think of these matrices as 'extracting' 'features' of an image works against our ability to understand that vision involves numbers of networks recurrently connected and working in parallel. Rather than imagining a retinal image propagated from the eye to the brain it is probably useful to think of the retina as transparent or blind. Then we are more able to imagine the many systems of differential response as response not to an image but to objects, to backgrounds, and to the perceiver's own location and behavior. 3) Sensory action is an essential part of our ability to see, and proprioceptive response, response to the body's own perceptive action, is correlated with other sensor response at many points especially in the parietal and forebrain. What is happening in the rest of the body can codetermine what we see and where we see it: whole-body orientation, head position, gaze direction, gaze motion, and gaze slippage during saccades are all important. Eye convergence when we focus on nearby objects, and lens accommodation during focus at any distance, are especially critical. Saccades, fixation, and foveal magnification work together. Human eyes make a hundred saccades a minute; the fixation period between saccades is about 300 ms (Ballard 1996, 116). When we are looking, in other words, our eyes are moving about half the time. Saccades controlled from the superior colliculus in the midbrain often are not experienced as such. Another more intended kind of saccade is controlled from the frontal eye fields in the forebrain. The superior colliculus, the parietal, and the FEF are reciprocally interconnected, and the current position of the eyes is registered throughout spatial function areas, a constantly updated aspect of operational context that factors into seeing as it is accomplished. Gibson describes saccadic eye motion as being like the sweep of a palm across a texture again and again. An orderedness of illumination discontinuities and gradients is present in the array as a standing structure the eyes' motion is sampling "like a blind man feeling an object on different sides in succession" (Gibson 1982, 154). 4) Vision is not instantaneous, although it seems to be. Like other, slower senses, vision is essentially integrative over time as well as space. This is so as early as the retina, where rods and cones have refractory periods and respond as a function of photons absorbed within some specific time period. That visual structure is cumulative also in cortical areas which are the means of sentient vision is shown by the fact that we see video images all at once although they are scanned onto a screen pixel by pixel. We see consciously by means of a subnet of activity in the cortex which accumulates structure across time periods that include many saccades, many fixations. 5) Foveal and peripheral vision seem to be seeing different things by different means. About half the 1.07 million retinal ganglion cells serve the central 16 degrees of the retina. Foveal vision, whose resolution is the combined result of central focus and of the greater density of receptors at the center of the retina, seems to be essentially involved in object vision. It enables color vision, stereoptic depth vision, and our ability to track a moving object and not just intercept it. The contrasting form of vision should probably be called non-foveal rather than peripheral, since there is at least one system of retinal neurons that responds to events over the whole of the retina, but without added resolution at the center (Zeki 1993). Non-foveal vision seems to be vision not so much of motion as for the purpose of motion. As such it is particularly relevant to locomotion and to perception of backgrounds. 6) The classical notion of a hierarchy in cortical visual response is metaphorical and inexact. V1 and V2 are visual receiving areas at the occipital pole. There are many secondary visual areas; Van Essen (1992) reports 32 areas with some retinotopic organization in the macaque, 25 thought to be primarily visual and the remaining 7 thought of as polymodal. Secondary visual areas are much smaller than V1 and V2. Most are less than one tenth their size. Until recently, we have thought of the relation of primary and secondary visual cortex as hierarchical, differentiations made at V1 and V2 being early stages of 'processing' finalized further on. At the same time, theseareas are thought to be the areas most important to conscious vision, because conscious vision can survive lesions to secondary areas but not to these primary areas. It has not been obvious how the supposed lowliness of V1/V2 in a hierarchy should be reconciled with the centrality of these areas to conscious vision. The fact that forward connections are usually reciprocated, along with Edelman's notion of synchronous recurrent reentry, can help with this puzzle. We should probably think of V1/V2 as organized simultaneously from above and below, by a convergence of response propagated from sensors and from the many contextualizing matrices in secondary and multimodal association cortex (Farah 1990, Pollen 1999). 7) Finally, the visual system is robust but tunable. Sensitivities of neurons as early as the retinal ganglion can be altered via recurrent connections with more central areas. The more important tuning, however, is the tuning set up by the environment. When we look at different things, and when our visual circumstances change (illumination for example), differential response propagated from the retina will automatically activate different through-paths, customizing the system to existing conditions. Looking at something with central focus will, for instance, activate focal subsystems right through the brain, and these subsystems will automatically activate other subsystems at many levels. Similarly, patterns of response in peripheral areas will automatically activate other subsystems at many depths. These subsystems can function coherently in parallel because the visual system has evolved and developed in surroundings where many kinds of spatial fact -- facts about body, world, and their relation in action -- are consistently correlated. This consistency allows cortical function to be coherent overall. 2. From Leaving the land: perception and fantasy (EE) So another way I work to stay in touch with my original piece of land is that I work to defend the very idea of it. One of the things that means is defending a description of perception that supports peoples' ability to be and stay in contact with the here and now which is their land. In the last ten years a lot has happened in neuroscience, and subsequently in the connectionist philosophies of mind that track these findings. We have discovered things about the brain that have instantly revised centuries of error in the ways we've talked about perceiving and about the relation of perceiving to thinking and knowing. There are a number of new ideas that seem as if they can be really helpful, and I want to describe some of them briefly. The first one isn't new, of course. It's evolutionary theory, which is our form of creation myth. It's one I like a lot, because it says that the universe, rather than being created from outside, by some outside guy or some outside force, is self-creating. It's self-creating from the beginning, and we are part of its self-creation. Human beings have this lively and minutely organized, not at all chaotic, but exquisitely complexly organized, history and actuality as self-structuring entities in a universe which is also that. What it amounts to is that we are made by the land, we are made as part of the land. The implication then is that perception is the complement of the land. It is the complement in human beings, of the land. Perception is how the land itself has constructed us capable of being in contact with it. The second idea is a correction of the more recent academic fad for talking about perception as if it and every other kind of mental action were a kind of computation. Perceptual computationalism is a new variant of old forms of representationalism. Hume's version talked about perception as involving images "in the mind"; a 1980s version talks about codes in the brain. Both have a kind of brain-in-a-vat feel, as if perception is a purely internal transaction. What they leave out is the sense of a living creature in active contact with a world. Contact means two things: a person or animal who is perceiving is often acting on the world, going up to something, touching something, poking its nose into something. At the same time it is entered by parts of the world, deeply altered, structured by the world. When we are attending to where we are, we're spatially and temporally entrained by patterned energy -- we're synchronized with what's with us. A perceptual state is a physical state that's relevantly, responsively organized; perceiving is relatedness. It is more like feeling than it is like calculating. Suzanne Langer and James Gibson were making these points in 1942 and 1956, but they weren't understood. What's different now is that brain science has got more of the detail of what can be meant by saying a sensory system like vision or audition actually resonates with something happening in the world. Another very old misunderstanding about perception -- it goes back to Plato or before -- says that perception is simple, animalistic and primitive, and that the really sophisticated, evolved and important capabilities of human beings belong to some other faculty, like 'Reason'. In fact perception in any organism is as complex as that organism is. A human brain in the act of perceiving is probably the most finely organized kind of complex structure in the world. Perception doesn't even have to be specialized to be virtuosic. Think of a day when you drive for twelve hours through landscapes you haven't seen before, sixty miles an hour on two lanes with oncoming traffic, different colors of light and times of day, towns, all kinds of terrain. Think how much you've seen in such a day. Think of how much you've had to do, as an organism, to see so much. We get it right, we get it right in the most complicated circumstances, and the ability to get it right is stable through hunger, sickness, lack of sleep, great changes of locale. We get it right because we're aboriginal to this planet; we're all aboriginal to the real. The misunderstanding that says perception is simple is usually the same one that says that other capabilities, which are thought to be the truly human ones -- like thinking, speaking and imagining -- or doing math or designing jet engines -- are accomplished by 'faculties' or parts of the brain other than perception. The recent evidence is that all of these abilities necessarily and centrally depend on structures formed in the processes of perception, for the purposes of perception. What we see in PET scan and magnetic resonance imaging is that when we think, imagine, speak and dream, it is sensory cortex that lights up. When we talk about a bird we're using some of the same tissue we use when we're seeing a bird. Reasoning and imagining, rather than being apices of some hierarchical progression are actually subabilites of a more general ability to perceive. Another related misconception is that perception is only of particular things, and we need a 'higher' faculty to give us categories and other kinds of abstraction. Kant for instance said categories have to be applied to the materials furnished by the senses by the faculty of Understanding. But the world builds the brain so we see things immediately as kinds of things. Eleanor Rosch, a perceptual psychologist who was first writing in the 70s, worked something out that has been used a lot since. Her discovery was that, at a base level, which is to say at the level most relevant to the survival of animals and humans, perception is automatically categorical. In other words, we see categories before we see particulars. Categories are the easy part of perceiving. The world builds the brain so we'll run away from all tigers. As we get smarter and more experienced we're able to see differences within a category. As we get to know someone better, we begin to see that although they're still them, they look different every day. It's the same with the land, anything. The deeper we get into something, the more we are able to see the particularity of it, so that the higher function, the more experienced or the more educated or the more evolved function, is to see particulars as particular. Our notions about the relation of perceiving and abstraction also need to be turned around. The new evidence is that abstraction has to do with using parts of the brain in a segregated or dissociated way -- literally abstracting from the normal completeness of perception. For instance, the parts of the cortex we use to see are quite widely distributed. Primary visual cortex is in the occipital lobe, right at the back of the skull. Premotor cortex, which controls eye movements, is in the frontal lobe. Color vision and visual object recognition happen in temporal cortex, behind the ears, but the parts that have to do with space perception are in parietal cortex, higher up and more toward the back of the head. So in ordinary vision there is a kind of wide net of interconnected activity, which I sometimes imagine as a kind of tree or 3D lacework made of light. As we see different things the light structures shift. If we are thinking about space in an abstract way, when we're doing math, for instance, we use the area in parietal cortex that's used for space perception, without using the other vision centers; we're using just one quadrant of the tree. Color field painters presumably are isolating the temporal area that does color perception. We can learn to segregate sensory areas in endless different ways, but none of these ways are 'higher' than perception. They are just culturally supported ways of using parts of what in every day perception is an integrated whole. Another misdescription of perception -- I think this is number seven -- is that we perceive with our outside edges, that we see with our retinas, feel with our skins, hear with our ears. That isn't how it happens. Perception starts at the sensory surfaces, but goes on being accomplished by structures at all levels all the way up to the cortex and then looping back down into the muscles. And the senses aren't functionally separate from each other on the way up: vision, hearing and muscle proprioception are collaborating as early as the midbrain, and they go on feeding back onto each other all the way to the cortex and beyond. Space perception in the parietal for example is heavily visual but also has converging fibers from auditory and motor cortex -- which is why blind people can do math. So it's not that there's one place in the brain where it all comes together and perceiving happens. We see and hear and touch with our entire nervous systems, and any moment of ordinary contact with the world will be a standing texture of simultaneous microperceptions, normally integrated but sometimes, transiently, separable. Another thing that isn't generally known -- this is my last point -- is that our brain can change quite a lot depending on what we do. People who practice playing an instrument, for instance, massively increase the number of neural connections available for fine finger movement. We customize our brains. Someone interested in certain kinds of perception can actually increase the amount of cortical tissue they use for that kind of perception. This explains how people can develop unusual kinds of skill. A physicist called Evelyn Fox Keller wrote a wonderful book called A Feeling for the Organism, which is about a corn geneticist, Barbara McLintock, who got the Nobel a few years back. It is the story of the development of McLintock's ability to perceive the genetic structures she was tracking. Out in the field, she knew the plants individually. She knew the shapes of their leaves and their growth habits and the colors of their kernels and so on. So then, when she looked at slides under her microscope, she got so she could see the individual genetic components of a plant. She could tell which plant the slide was from. McLintock did science by working up an always more informed integration of theoretic knowledge and eyesight. Keller called it erotic science, because it was science based on contact. It was not science done as if by aliens: it's science as done by someone who knows the land has made scientists as well as corn plants, so a scientist can adapt herself to a corn plant well enough to be able to really know it. The world exists and we're made to perceive it. We're also made to act and make. One of the things we can make is our own ability to be with where we are. We begin instinctively, but then we can work at it more deliberately. The perception of a mature, smart, brave, adventurous, experienced person has great virtuosity, great idiosyncrasy, and also great contact. Such people can be in community because they have formed themselves to be deeply in contact with a common world. And, since it's the perception-built brain that's used for everything else -- even for dreaming, which is fantasy at its limit -- people who are or have been in good contact with land will also be well-founded when they're making it up -- writing novels or designing jet engines. 3. Excellence / ethics / aesthetics / epistemology
She understood that the colors and textures of the world we live in are body to our sense of self. Djikstra of Georgia O'Keefe, 1998, 3 If the necessary conditions of human aboutness include the human body and its environment, our paradigm of knowing should no longer be the self-conscious ponderings of a man shut away dreaming alone in a room. Manners of speaking founded on alienation and incapability rather than contact and efficacy become suspect. Taking it further, an evolutionary account of knowing and intelligence seems to me to imply an ethical imperative within which the arts and every other human enterprise would share an interest in the conditions needed for excellence of contact.
Our evolved origins imply the central value to persons of contact with the world in which we are native. If there is a real world, contact is gold. If we are structured to succeed in that world, abilities to be present, perceiving and acting, are of primary value. Perception and action in the real world is our cognitive base. There are depths of order in the natural world - many scales of order coherently co-present. Color, texture, smell, timbre, motion, and shape are all aspects of this order. Our ability to perceive order is our ability to respond with order of our own. Perceived complexity of order always implies that we ourselves are complexly ordered in perceiving. We can see only as much order as we are capable of embodying. When we imagine perception as perception of an image or other mental representation, we imagine it as a sort of skin of appearance projected onto objects. Perception understood as responsive structure, and, further, as multiple, simultaneous, interactive, differentiative, self-organizing response in a widely distributed structure, can be imagined as deeper and wider than sentient perception. There can be responsive structure that is not part of sentient structure, and it can also be more or less accurate, more or less complex. 'The unconscious' can also be more or less responsive, more or less accurate, more or less complex and ordered, and above all more or less integrated with sentient structure. Perception must be understood to be knowledge and it must be understood that there are degrees of excellence of perceptual knowledge. Learning to perceive more builds out from a core or base of evolved ability. Perceiving becomes more particular - we can become more able to perceive particulars in detail - and it becomes more general - more deeply, widely, exactly, and flexibly categorical. If we can think of perception as complex, there is less need to differentiate perception from what was called insight or understanding. The whole gestalt of response in the moment can be understood to be perception. We perceive not only the thing, but what it can do - its effectivities - and what we can do with it - its affordances. Theoretical understanding may be built into the nets by means of which we perceive. With theoretical instruction - theoretical structuring - we may for instance become able to see principles of formation. When we see something in the world we may be able to see how it is organized, how it functions, how it came to be. When we see differences of color of plants on a dry hillside, we can see the course of water in another season. Looking at streaks on a shell or spots on a giraffe, we can see the reaction diffusion processes that engendered them. Looking upward at the Milky Way we can see it as our galaxy's horizon (Churchland 1989). Looking at colors on an oil slick we can see the relative depth and the rapid reorganization of areas of a thin film. In perceiving objects, it also happens that we can perceive their relations, and even our specific relatedness to them, for instance our own emotional or other evaluative response as such. We may also momentarily be able to see them as they will look to someone else whose habits we know. Understanding perception as responsive structure implies something about perceived beauty too. Perhaps it implies a goodness of fit between the object's order and our own, a fit that makes it possible to respond well: clearly and vividly. The simplest way to talk about beauty is probably in terms of liking - liking to perceive, liking to be that form of order. Beauty is thus not subjective and it is not objective. It is a structural fact of some sort, a co-determined fact: something about it, something about us.
Do we know what to mean by excellence of cognitive structure? There are clear cases of cognitive failure, structural disorganization, failure of aboutness. They include failure to thrive, failure of energy and health, failure to act in one's own interest. Madness, alienation, withdrawal, a life in fantasy. Incoherence, or coherence so fragile it can only be sustained within a contracted sphere. Narrowness, conformity, dogma. Imperception. Isolation, depression, anxiety. Irresponsibility. By contrast, good structure - a good soul, psuche - would show vital competence: energy, flight, detail, scope, autonomy, fertility, enjoyment, coherence, love, street smarts, vividness and trust, effectiveness in being alive. If there is such a thing as excellence of aboutness, we become interested in therapy/ethics, that is, we study how contact is spoiled and how it is restored. For example, we need an understanding of lying, of addiction (which is a form of biological lying), and of the ideological pathologies founded on evasion. An evolutionary epistemology suggests that maintaining a clear distinction between contact and simulation is important. We need to stay aware of the limitations and powers of simulational cognition. Excellence of simulation might itself be judged in relation to its perceptual origin. We might ask of imagining how accurate it is, how comprehensive, how integrated. If contact-cognition is the gold standard and if abstract and simulation-based cognition is, structurally speaking, less secure, more prone to dynamical freewheeling, we should also be particularly aware of the fragility, the relative ungroundedness, the limitations of thinking structured simulationally. We could make conscious and provisional use of structural metaphor, for example. Such metaphors work, in a way. There is something we are able to do by means of them. Something about them feels right. But they are forms of fantasy and need to be understood as such. If the tendency to think in asymmetrical binaries is understood as fantasy, for example - the deep necessity to think by saying "...on the one hand, and ...on the other hand" - the need to make one of the hands always preferred becomes less compelling.
What does the biological sense of mind have to do with art: excellence in art, the value of art, directives for art? What could a biological sense of mind add to the practice of art? A new biological epistemology seems to me to be a base for an aesthetical ethics, that is, an ethics for the makers and users of representational artifacts. Accurate responsive self-construction, over time, and in the moment, seems to me to be a personal imperative implied by evolutionary realism. This is not to say that anything is simple. There are always interests to be balanced. There must also be provision for the self-construction of others. But these interests may at times be aligned rather than competing. Evolved effective structure comes into being through necessary mutualities: through epistemic reciprocity. Perception requires world structure and personal structure equally. Ordered persons require ordered communities. Excellence in art has traditionally been described as excellence of the art object. This description belongs to the tradition that thinks of the representational object as the locus of representational effect. Excellence of representational making needs cognitive excellence of the maker, however, and requires and creates excellence of aboutness in the people who use what is made. The excellence or value of an artwork, like the representational effect of any representational object, will depend on something about the maker and the user as well as on something about the object itself. What are the implications for art (or science, or philosophy) if they are seen as practices requiring and forwarding the effective formation of persons? Excellence in art can be thought of as a subset of representational excellence, but it is related also to excellence of nonrepresentational making, for instance excellence in the making of boats, houses, meals, gardens. It is further related to excellence in friendship, romantic love, child rearing, education, community activism, and other sorts of intervention in the making of persons. All are, like art-making, subsets of excellence of aboutness. Representation-makers are like magical operators in the sense that they use perceptible form to evoke illusion. Like magicians, artists have and rely on powers of seduction. If representational experience structures us, and if most representational experience is simulational, and if the simulation evoked is shallow or false, art can be used to disorganize, to ruin cognitive order. This is where aesthetics and ethics overlap. Artists need to understand the relation between artifact structure and human structure. A well-ordered thing will be more able to set up a well-ordered person. If the ordered thing that structures us is made by someone whose own structure is in wide, competent contact with the world in which we evolved, it will structure us in ways congruent with our foundation. In these ways cognitive value is added. Humans structured by art become more able to enact and to enjoy contact. - Ellie Epp from Chapter 10 of Being about: perceiving, imagining, representing, thinking
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