Living things come into being in collaboration with the world. They are embedded in a consistent world whose regularities are embodied in them. Evolutionary success of an organism can be seen as a successful embodiment, a coherent coupling between a changing organism and its changing world. Survival depends on the cohesion between the organism and its world. -student Jody Golick
I believe it is possible to experience Merleau-Ponty's radical undoing of the traditional "mind-body problem" simply by dropping the conviction that one's mind is anything other than the body itself. If one is successful in this then one may abruptly experience oneself in an entirely new manner--not as an immaterial intelligence inhabiting an alien, mechanical body, but as a magic, self-sensing form--a body that is itself awake and aware, from its toes to its fingers to its tongue and its ears--a thoughtful and self-reflective animate presence if one maintains this new awareness for a duration of time, becoming comfortable enough with it to move about without losing the awareness, one will begin to experience a corresponding shift in the physical environment. Birds, trees, even rivers and stones begin to stand forth as living, communicative presences. -David Abram,"The Perceptual Implications of Gaia"
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I believe it is possible to experience Merleau-Ponty's radical undoing of the traditional "mind-body problem" simply by dropping the conviction that one's mind is anything other than the body itself. -David Abram
Embodiment epistemology: philosophy of mind, evolution, perception studies, cognitive science.
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.
We have thought of knowledge the way we think of wealth, as something that can be put away in treasuries or concentrated in precious objects. If knowing is something I am, not something I have, an implication is that knowledge as such is not storable outside bodies: knowledge as effective cognitive structure can only be constituted and reconstituted in individual bodies. Middlemarch and the Philosophical investigations cannot hold knowledge -- they can evoke, build, organize it, but only in bodies already capable of reorganizing themselves to fit, and only in a world able to produce such bodies.
At one point that night I had to let go of her because the force of seeing was so strong, I had to look out and up at the trees and the moon. And it began again, the oh oh. I was shaking and the sounds I was making were the same as when I'm close to coming. And I suddenly understood that knowledge and love really are the same.
Receiving the world was knowing the world, but not in the sense of coming back to old knowledge or an old friend, no it was intensely new and exciting, on the edge of discovery like writing a poem or a story where suddenly connections are made and sparks fly. And it had such an intensely sexual charge to it, like the moments before climax, receiving knowledge that is never the same yet always the same, that never loses wonder and awe.
Oh oh, it is not simply the approach of pleasure, it is knowledge of self in its most intense concentration on joy, it is testing our capacity for pleasure as if to say so this is what I am capable of. Self discovering an ability to tune itself to so intense a pitch. Living on the edge, not in the sense of taking risks, defying death, but in the sense of living in my senses at their sharpest, every nerve and cell turned inside out to receive the world. This is the way the world enters us - a tree, another body. We can know through our senses if we receive with this kind of absolute attention. And love. This new way of knowing is the way I am getting to know Mary. Knowledge is love. Knowing is loving - yes that's better, it is in actions, in movement, that they are the same.
-Lise Weil (April 1981)
Three excerpts on perceptual epistemology in general and vision in particular, © Ellie Epp 1998-2002
Audition: an example (from Being about, Chapter 3, Perception)
This chapter has been considering how perceptual theory should change if we think in terms of whole body structural adaptation and cortical wide nets. The main points so far have been these:
1) Perception has two aspects always -- what is done to be oriented to something somewhere in an environment, and what occurs throughout a cortex as a result.
2) Cortical alteration as a result of sensor engagement with ambient fields is co-caused by things in the world and the existing structure of the organism.
3) Perceptual structure is distributed across many nodes along streams traversing most of the cortex. What happens at these nodes coordinates many kinds of aboutness simultaneously.
I have said that to be able to think better about perceiving and other sorts of cognition we need to be able to imagine how it is done. In this section, I will go into some of the technicalities of auditory aboutness and its cortical facilitation.
Audition is not simple, but it is simpler than vision, and it is the sensory mode we understand best. My description draws on recent neuroethology and its interpretation in connectionist models. Like much of what I have to say, it owes much to James and Eleanor Gibson. I see the neuroethology reported below as confirming and extending their vision, and the connectionism as explicating their notion of tuning.
Mediated distal perception
The atmosphere can mediate acoustical contact because it is elastic: it takes and propagates structural alteration. A vibrating object broadcasts every tremor. When one blade of grass is blown against another, every detail of the temporal structure of that tiny event travels away from it in all directions. Anything happening on a scale that starts a pressure wave train patterns the air.
Near its source, a wave train is precisely correlated with object, event and location: its component periodicities, their relative energies and timing, are exact consequences of what happened and what or who it happened to. Because pressure wave trains travel outward like expanding concentric spheres, they also are exact consequences of where it happened.
A complication is that all these crossed and interwoven wave trains reflect, or are absorbed, or partly reflect, or partly are absorbed, wherever they meet an obstacle or change of medium. The perceiving creature, standing in the atmospheric sea, will intercept many wavetrain versions of the same event, or will intercept a wave train when its energy is unevenly attenuated.
But order lost can here be seen as order gained. Wave trains converging on the perceiving creature are changed in ways precisely correlated also with where they have been -- through miles of desert air, back and forth inside a canyon, under a door. Pressure wave trains by the time they reach the perceiver also are exact consequences of the atmospheric conditions and the reflective and absorptive environment. In consequence, many things about the surrounding world are specified at any point in an acoustic field; particular objects or events or directions or atmospheric facts will be specified by different covariances present in the array. Creatures who hear at all hear successfully, so we know auditory systems are able to do this very complex thing -- comb out the different covariances that specify object, location and environment.
We do not hear with our ears. We hear with the help of our ears, but properly speaking we hear by means of the entire auditory system -- all the streams, loops, matrices and multiplexing through-nets of the auditory nervous system, and all the motor states by which we search for acoustic pattern. Senses are not end organs: they are systems that reach all the way up into the brain (where they intersect and interpenetrate other senses) and then down again into muscles that turn the head or twitch in the pinna.
Hearing is knowing by means of the auditory body. Auditory knowledge is the spatiotemporal structuredness by which the listener is managing to hear, and which is occurring so that the listener's auditory system can pick out one set of higher-order patterns rather than another. Auditory competence is the listener's pre-structure, the auditory system's inherent and experienced order. The listening moment is that pre-structure selectively, responsively active, picking out, "resonating to", higher-order pattern in the ambient array. It is a listener physically configured in a way that is specific to something about the world, to what is being heard.
A listener comes to be so configured by being in contact with the world. Pressure wave trains are patterns of impact. The world never stops touching us. It can touch the inside as well as the outside of our bodies: when a helicopter rises over our heads, we feel ourselves touched in all our tissues. Some voices are felt as very pleasant touches in the solar plexus. Other kinds of acoustic touch are so fast and sharp we don't feel them as touches, and yet we hear by means of them because and only because they are touches. They literally communicate with us: they communicate energy and pattern. The tympanum is the window by which the smaller-scale patterns can get into us: a bottleneck. From that point on it is the wider nervous system that finds the patterns in the patterns.
We are temporally entrained by what we are hearing: when we hear a truck shift down at the lights, we hear it not quite when it happens, but in the order that it happens. And we are spatially reorganized in hearing it, though in very minute ways. Temporal entrainment and responsive spatial reorganization are what Gibson means by resonance. What Gibson's approach gives is a way of understanding the acoustic and neural processes of perception not as signal processing but as comprehensive contact.
Generally speaking we hear the sorts of things we have evolved to hear -- the sorts of things that are relevant to the kind of creature we are. We hear what we can attend to. We don't hear the fluttering passage of a raised dot on a moth's wing, although a bat does. We do hear our friend's pleasure or the wetness of the street.
Hearing a seagull fly over the roof we are also hearing the open air that allows its passage. In the particular balance of the seagull's cry with traffic noise we hear that it is early morning. When we hear a train at the crossing seven blocks away we are also hearing the presence of that reach of space around us.
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From Leaving the land: perception and fantasy
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.
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About vision (from Being about, Chapter 3, Perception)
Ecological optics is less concerned with seeing light than with the seeing of things by means of light Gibson 1982, 75
This chapter's remarks about vision are intended as establishing general guidelines for a discussion to be continued in more detail in Chapter 4.
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.