The Depth of Consciousness

By Chris Chandler

Summary
The Problem
Ways of Knowing
An Answer to the Problem
The Center of the Universe
The Vision
Cosmology
Comparison: Double Image in the "Background"
Comparison: Concise Similarity in Focus
Stereopsis
Stereopsis in more Depth
Linking Back
On the Other Hand...
What is left?
Postscript
Footnotes
References

Summary

The mind-body problem, or hard problem of consciousness as the scientific community is coming to address it, is one that requires of us a difficult psychological commitment if it is to be adequately addressed. The ways in which we individually and collectively explore our world are many and diverse. It is only in the experience of participating in more than one of these ways of knowing that we may hope to achieve a level of insight into this long-standing philosophical problem qualitatively up to the task. Such an approach is highly subjective and it requires the upmost care to keep from inadequately blending the two ways of knowing into a muddled mush. Nevertheless, this is the challenge that must be faced in order for the scientific and moral problem of the West's understanding of the relationship between mind and body to be successfully understood.

The Problem

It has been nearly a whole century since mainstream academia has last seriously discussed the subject of 'consciousness'. Yet, in the last four years, there has been a community building in the traditional sciences around this very topic; graduate programs are even beginning to form on 'consciousness studies'. As the millenium approaches, scientists and philosophers of science are examining ideas and experiments in order to see what can be made ontologically of Descartes' famous "I think, therefore I am" (1968). One popular way of conceiving of this new scientific endeavor has been put forward by the philosopher David Chalmers(1995) as follows:

The really hard problem of consciousness is the problem of experience. When we think and perceive, there is a whir of information-processing, but there is also a subjective aspect. As Nagel (1974) has put it, there is something it is like to be a conscious organism. This subjective aspect is experience. When we see, for example, we experience visual sensations: the felt quality of redness, the experience of dark and light, the quality of depth in a visual field (p. 201).

It is truly exciting to see that scientists are willing to tackle the essence of subjectivity, giving it the same dignity of serious acknowledgement as Descartes did so long ago. The question now is, is the subjective experience of consciousness amenable to a scientific mode of inquiry? In other words, can science solve the mind-body problem?

While the more traditional areas of academia are beginning to see the light of the significance of the mind-body problem, other 'cultures' of academia have been concerned with the mind-body problem for quite some time. This philosophical problem is often seen in these alternative cultures of academia as a moral problem for Western culture in a general sense. In this view the mind-body problem (or 'split') is a problem with far-reaching, even possibly disastrous, consequences if it cannot be satisfactorily addressed.

It is my hope to address both cultures of academia and discuss one out of a whole "world" of possible answers to this mind-body problem. But first I would like to explore a particular concept that I have often encountered in the alternative academic culture. Then I will say more about my "answer" to the mind-body problem.

Ways of Knowing

Perhaps the most important insight into the mind-body problem to come from the alternative academic culture is the notion of a 'way of knowing'. The term generally means any way in which an individual or group, in the search for 'truth', formulates questions, pursues answers and verifies those answers. These ways of knowing need not be ones that the knower formulates logically. They are not usually formally analyzed epistemologies, although they may be the result of a great deal of intention, thought, reflection and experience. On a collective level there are established ways of knowing that are supported by the community as a whole or in part.

These ways of knowing may be understood to involve biologically rooted cognitive processes, psychological personality types, culturally and spiritually informed beliefs and practices or even unique habits of learning behavior. Any sense of looking for the truth in one's life through participation in such collective endeavors as science, politics, art, religion and/or sports is an example of participation in a collective way of knowing. Personality tests and learning style tests, which explore the individual's preferences in these areas, suggest the existence of ways of knowing on an individual level. In the investigation of these ways of knowing there is usually little or no judgement as to what method is right or wrong, true or false, for the idea is to capture what exists, what seems to work for people from their own point of view. The underlying assumption is that there can be no serious study of ways of knowing that attempts to use a particular way of knowing to validate them.

The supposition that there exists more than one valid way of knowing implies a spatial geography for human truth that is analogous to how we are now to understand, according to the special theory of relativity, that there is no privileged frame of reference by which we can measure the motion and position of physical objects in the universe. In other words, according to the best science, one person's stop is another person's go. Of course, this does not mean that an objective sense of the measure of motion and position is entirely lost; all you have to do in physics is declare your inertial frame of reference and the objective laws of physics will hold with little controversy. Similarly, the existence of multiple ways of knowing does not imply the loss of an objective sense of truth between knowers, only the perpetual relevance of one's sometimes very personal frame of reference. This unavoidable subjective dimension of one's sense of the truth and the bias that it casts upon our psyches is a challenge that must be faced and not a problem to be circumvented or even objectively solved. This is the moral challenge of engaging with people different than us, with different views, who are equally inquisitive and equally sincere in their pursuit of truth and meaning. It is also the gateway to understanding the mind-body problem.

It seems to be a rule that individuals develop a preferential relationship to certain ways of knowing in certain contexts. Challenging one's own monocular view is a great personal struggle. It begins with the realization that other ways of knowing besides the one that you are familiar with may be equally as valid even if they don't make sense or seem right to you. This is often extremely difficult to realize due to the fact that different ways of knowing are differently able to formulate objective views on the one world that we live in, and, thereby, will be made to seem inferior in the eyes of one's favored way of looking at things. Judging the value of the formulations of an "alien" way of knowing using one's own preferred way of knowing is an endlessly circular way of convincing one's self that one's own way of knowing is superior in a categorical sense. Usually, if one is to engage in a new way of knowing, there is a period of time during which one must struggle to learn how to make use of it. There is a period of time involving an open-mindedness, or faith, that holds back the sense of futility and incredulity that one will inevitably feel as the more familiar way of knowing voices its concerns. We are each unavoidably close to our preferred ways of knowing and bringing in another way of knowing inevitably causes conflict.

If one consciously undertakes to involve one's self in two different communal ways of knowing, especially two very different ones, then one will soon understand the appeal of sinking back into just one mode or the other. Where you may find it easy to go back and forth between the two, others will protest this indiscriminate thinking or behavior. These protests from either side are correctives that should be acknowledge, at least within that given way of knowing. They may not be applicable to the individual's search for truth as a whole, but when certain claims are made to a particular community, one must be willing to accept the standards, to some extent, by which that community understands truth.

A choice of which community one is involved in is obviously crucial to individual integrity, and a diversity of choices is a healthy feature of any extensive human society. However, even supposedly democratic societies oppress the voice of certain cultural constituents because the controlling culture does not understand or value the truths of the suppressed ways of knowing. Any dominant cultural voice will tend to do this in at least some areas of its concern. There is a tension between being open to other ways of knowing and living one's life based on what one has personally established as true, reliable and meaningful knowledge. This tension, whether on a personal or a cultural level, is, again, not a problem to permanently solve but an unavoidable feature of the dynamics of interpersonal and intercultural engagement.

An Answer to the Problem

I propose that is it through this great personal challenge of bridging the gap between two fundamentally different ways of knowing that one may hope to address the gap between the Western sense of the mind and the body. Can science alone, which functions to paint an objective picture of the world, bridge the gap between that picture and one that convincingly includes subjectivity? My own sense is that science, as a collective endeavor, can only paint itself out of the subjective picture. That is why it is up to the individual to engage in another way of knowing in addition to science. From the personal, subjective combination of two ways of knowing may come the experience of an answer to this unique philosophical problem. The answer must be unique in the experience of the knower for the experience of understanding the subjective nature of consciousness best appears when we believe to have made a significant discovery.¹ Yet such discoveries, especially if they are deeply informed by two ways of knowing will be hard won and short-lived. The answer will come from the unstable relationship between the two voices of truth that the two ways of knowing represent. It is then up to the individual to attempt to find in that experience what is of value to him or her and to science.

It is important to understand that in this view an answer to the mind-body problem is, in an objective sense, a momentary and subjective experience. Further tinkering with an answer using either way of knowing will undermine this sense of having achieved and answer and a sense of disillusionment inevitably sets in. This dynamic scenario is necessary considering the problem. The very sophistication of an answer belies its own instability. The problem defies the rationality of any single way of knowing, and it is only in the moment in which two rationally distinct ways of knowing suddenly seem to correlate that an answer comes. When suddenly the two views combine then the answers come with a qualitative strength far above anything either way of knowing could achieve independently. The answer will be in the pairing of seemingly coincidental or otherwise dubiously related views that seem to unite the two great worlds of the mind and the body. All one can do is try to preserve the original moment and hope that others will still be able to catch a glimpse of your answer in that form of preservation.

Not only is it difficult to "talk the talk" of two ways of knowing, but to "walk the walk" is an even greater challenge. Humbly I hope to demonstrate in what follows that this may be done. I think you will find that this article, as a whole, rests somewhere between a kind of story involving a small cast of diverse characters (scholarly views) considered one after another with equivalent emphasis and a concisely woven argument with a single train of thought. In addition to making use of scientific insight into the nature of consciousness, I will also be drawing upon a moral reading of myth. I hope that I may treat both the scientific and mythic subject matter in a way that will not alienate those educated in either. I am asking for the reader's trust now, and I hope to have earned it by the end of this paper. At the same time, I hope to show how perspectives from these two ways of knowing can allow us to see something in the nature of consciousness that we would not have been able to see with only one way of knowing. By attempting to ground my argument in two incompatible ways of knowing, I hope to demonstrate the elusive quality that is the mind-body relationship. It is this experience of trying to chase down an answer, with all its moments of success and failure, that I claim constitutes how one may answer the hard problem of consciousness. Out of this pursuit there will be fruits for the scientist.

Now I will begin to tell a story of, and so make an argument for, how this problem can be solved.

The Center of the Universe

Where am I/are we located in the universe as a whole? The popular tale tells that Western science has forced us out of our presumptuous belief that the universe acts as a kind of glorious frame around the preeminent activity of human beings. It has done so by placing us in one tiny corner of one of an astronomical number of galaxies. This classic battle between religion and science, between old common sense and subtle empirical discovery is still told. It may, then, come as somewhat of a surprise that there is a scientific view to match a particular mythic view that states the following: as we look with the widest possible vision at the shape of the whole universe, we are, in an intriguingly paradoxical way, in the center of the universe. In what follows, I will describe the vision that Black Elk, a healer of the Oglala Sioux, had as a young boy, and I will describe one cosmologist's account of a standard assumption of his peers. Both of these views agree that everywhere is the center of the universe. After describing these two perspectives I will suggest how this intriguing "agreement" is no agreement in any intended sense, but it may point toward the nature of consciousness.

The Vision

As a young boy lying very sick in bed, Black Elk had a great vision. As he lay unconscious he saw two men approaching from the sky. They escorted him up into the clouds. He was shown a great many things by the beings that were there. He was led forward through history to be shown something of the suffering his people would know. He was taught how to treat the suffering and given gifts in order to achieve this healing. Eventually he was brought to the "center of the earth" (Neihardt, 1932)

Then a Voice said: "Behold this day, for it is yours to make. Now you shall stand upon the center of the earth to see, for there they are taking you."

I was still on my bay horse, and once more I felt the riders of the west, the north, the east, the south, behind me in formation, as before, and we were going east. I looked ahead and saw the mountains there with rocks and forests on them, and from the mountains flashed all colors upward to the heavens. Then I was standing on the highest mountain of them all, and round about beneath me was the whole hoop of the world.⁸ And while I stood there I saw more than I can tell and I understood more than I saw; for I was seeing in a sacred manner the shapes of all things in the spirit, and the shape of all shapes as they must live together like one being. And I saw that the sacred hoop of my people was one of many hoops that made one circle, wide as daylight and as starlight, and in the center grew one mighty flowering tree to shelter all the children of one mother and one father. And I saw that it was holy.

⁸Black Elk said the mountain he stood upon in his vision was Harney Peak in the Black Hills. "But anywhere is the center of the world," he added.(pp. 42-43)

One can allow one's own imagination to recreate a sense of what Black Elk might have seen. Add to that the power of a dream to convince us of its reality while we are "in it", and I think most people would understand that such an experience is possible, even if they choose to believe it was all just a dream. What I would like to examine is a possibility that lies hidden in the above quotation from Black Elk's vision. This possibility comes from a personal insight that I have had that was inspired by the vision that Black Elk has had. In the way of knowing that is myth it is entirely permissible to respond to a vision with one's own vision. What proves the truth of such a response is a matter for one's heart. So you the reader may judge what follows but make sure your heart is in that judgement.

I believe that in this vision, Black Elk may have seen, in a geometrical sense, a paradox involving the notion that every people's moral center is the center of the world and that no one people's moral center is privileged above any other's. Black Elk describes how he saw the sacred hoop (or circle) of his people. Harney Peak marks the center of the world for Black Elk's people. It is the tallest peak in the region and will afford anyone who stands at its top a view of the horizon all around. But the horizon-hoop as seen from this vantage point is but one of many horizon-hoops. The other hoops are the hoops of the other peoples of the world. Yet, Black Elk is recorded to have said, "But anywhere is the center of the world." I believe that this statement applies to his vision of "the shapes of all things in the spirit, and the shape of all shapes as they must live together like one being". I am somewhat justified in this as Black Elk states his inability to fully express what he saw at this point: "I saw more than I can tell and I understood more than I saw." I believe that the footnote truly belongs there as more than a simple aside.

As we all know a circle has only one center. But what of a circle composes entirely of circles? Where does the center lie then? We may picture the "mighty flowering tree" as standing in the center of a chain link fence of the people's hoops. But I think that Black Elk was struggling with an image that was paradoxical and that he had to struggle to find a sensible way to express this relatively inexpressible image although its message was also, somehow, loud and clear. Black Elk may have seen a paradoxical shape, a circle of circles creating a space where everywhere was the center. Such a geometry would probably have been unknown to Black Elk, but we may imagine it today because of our inheritance of scientific knowledge and mathematics. In fact, today, in the realm of cosmology, we have an equivalent vision of the universe that explains how such a paradoxical geometry can exist. So to explain further my supposition regarding Black Elk's vision, I would like now to examine a scientific view on the shape of the universe as a whole.

Cosmology

In what context would a scientist say that anywhere is the center of the universe? In a chapter from his book A Brief History of Time (1988), Stephen Hawking explains how scientists have come to understand that the universe is expanding:

[Alexander] Friedmann made two very simple assumptions about the universe: that the universe looks identical in whichever direction we look, and that this would also be true if we were observing the universe from anywhere else. From these two ideas alone, Friedmann showed that we should not expect the universe to be static. In fact, in 1922, several years before Edwin Hubble's discovery [that all other galaxies were moving away from ours], Friedmann predicted exactly what Hubble found!

...Now at first sight, all this evidence that the universe looks the same whichever direction we look in might seem to suggest there is something special about our place in the universe. In particular, it might seem that if we observe all other galaxies to be moving away from us, then we must be at the center of the universe. There is, however, an alternate explanation: the universe might look the same in every direction as seen from any other galaxy, too. This, as we have seen, was Friedmann's second assumption. We have no scientific evidence for, or against, this assumption. We believe it only on grounds of modesty: it would be most remarkable if the universe looked the same in every direction around us, but not around other points in the universe! (pp. 40, 42)

Any place in the universe we look out at the galaxies, we will see them all rushing away from where we stand as if we are in the center of a universe still exploding outward from its primordial birthplace. With the notion of the universe as a whole as an exploding volume, starting at a tiny point and increasing in volume as time passes, it would appear that every point in the universe now is in the center of that vast volume. As Hawking here states, he finds it a matter of modesty to think that this is true since otherwise our planet would turn out to be in the exact center of the vast universe. Not that being in the center necessarily means anything special for us scientifically. It is simply so statistically unlikely that it is highly suspect.

But how can everywhere in a volume be the center of that volume? The way in which Hawking's modest option is even possible is if we understand the shape of the three dimensions of space to be curved. One might ordinarily think of the expanding universe as the space inside of a balloon. A better analogy would be that the expanding universe is just the surface of a balloon. Where, on the surface of a balloon, is the center? This is like asking, "Which country on Earth is in the center?" Just as no country on the Earth is uniquely in the center of the surface of the Earth, no matter where you are in the universe, you are in the center of the universe. The trick then is to imagine a three-dimensional balloon surface in a four-dimensional space-volume (Hawking, 1988). This may not be possible in terms of mental imagery, but it is quite possible to express this in mathematics. This four-dimensional space-time is, in fact, the legacy of Einstein's general theory of relativity.

For Black Elk, his world was probably a two dimensional surface with a sky above and the earth below. The people's of the earth would be literally arranged within the wideness of the hoop that contains them all as "wide as daylight and as starlight", the hoop of the ultimate horizon. The shape then of these two-dimensional hoops somehow all having centers that are the centers of the whole hoop is indeed a paradox. This paradox could, to a great degree, be resolved if one were to then realize that Black Elk's two-dimensional world is curved in a third dimension as a sphere. If you think of each people in their separate land, and each with a spiritual-political- geographical landmark within their land that stands at their center, then one could again ask the question, "Which country on the surface of the earth is at the center of the surface of the earth?" The answer, again, would be that anywhere is the center of the surface of the earth.² So in both Black Elk's vision and Steven Hawking's description, a paradoxical belief about the shape of the whole world-universe, is resolved by the inclusion of an added dimension beyond what is commonly understood to exist in that world.

Actually you might say with equal accuracy that there is no center of the universe if you insist that a center only exists if there is a universally unique one. Either everywhere is a center, or there is no center. Either view is valid. The "no center" view removes the possibility of a center by its own absolute guidelines. The "everywhere is the center" view allows for an infinite relativity of perspective with a shared definition for the form of a center if not the location of a center. These two views on our location in the universe are analogous to the two main options available toward a scientific understanding of consciousness and subjectivity. The first option is to use a self-described objective way of knowing to try to understand subjectivity itself (the polar opposite in meaning of objectivity). But objective science automatically cuts out of the picture the possibility of subjectivity by its own apriori assumptions of what constitutes truth leaving the notion of consciousness an inapplicable one as some reductionists will argue.

The second option is to consider consciousness through more than one way of knowing and to attempt to understand what it is that these different ways of knowing agree upon that consciousness is. In the case of consciousness, however, we cannot expect anything like a simple consensus from all parties. In fact, we may expect quite the opposite, a dynamic relationship of perspective on this one word that mirrors the elusive character of the subject itself. To illustrate this I will now further explore the relationship between the vision of Black Elk and the science of Steven Hawking.

Comparison: Double Image in the "Background"

A way of knowing can be considered as a supporting background to any of its statements of truth. Even though these two views appear to agree on our significantly ambivalent location within the universe, it is easy to see that this same "truth" would be understood and built upon in extremely different ways in the mode of these two very different ways of knowing. One way of knowing is that of an oral, hunter-gatherer, mythic culture imprinted on a young boy. Black Elk was later advised by an old wise man to begin his career as a healer based upon this vision. So Black Elk's vision was a personal experience that served to shape his life, guiding him toward his vocation years before he would undertake that vocation. To underscore the depth of this moral vision it is interesting to note that in our own time this vision could be seen as a guiding, prophetic image for a world of relatively autonomous nation-states struggling to establish mutual trust and a fair, democratic world order in the form of a "United Nations". Such an achievement would be the realization of Black Elk's insight that no people are morally more central than any other.

The other way of knowing is embodied in a man raised in a literate (having a written language), industrial, scientific culture. Hawking, considering the nature of a bizarre vision of a four-dimensional, relativistic universe crafted by others before he himself became a scientist, helped to develop the theory of black holes. These incredibly powerful objects remain still an extremely remote phenomenon of less than certain existence. Certainly contemplating the strange shape of the universe and our place in it has played just as central a role in his life as it did in Black Elk's. But Hawking's universe is composed of massive stars separated by vast stretches of space. Black Elk's world was filled with people in mutual relationship. There is no morality in the order of the vast physical universe, only relative mathematical simplicity. Black Elk's world is permeated with a meaning of things being in a right order and appeals, as such, for its beauty, not to mathematics, but to the human heart.

If you were to approach Black Elk and ask, "How can everywhere be the center of the world?" he might have replied, "We each walk our own path. You cannot truly judge the actions of another unless you have walked a mile in that person's shoes." If you were to ask Stephen Hawking the same question you might get this perplexing response, "Well, if you were to start walking from the point you now stand out into the universe in any direction, then theoretically, if you do not divert from your original trajectory, you would be walking a path that leads right back to where you started." Each answer involves walking, but I think that you can see that they have little to do with each other otherwise. It should be obvious just how different are the two collective ways of knowing in which these two views are embedded. It would be difficult to say that these two worlds are at all comparable. Yet they do both say that the center is everywhere.

Comparison: Concise Similarity in Focus

As I have suggested, each view, supporting the notion that everywhere is the center of the universe, has done so by virtue of adding to the commonly assumed "shape" of the universe an added dimension. In both cases a rivalry between two or more perspectives is neatly resolved. In Black Elk's view it is the rivalry between each peoples' certainty of their own moral superiority. In the cosmological view it is the conflict engendered by the assumption that all the galaxies would appear to be moving away from any other point in the universe as well as our own suggesting that the expanding explosion of the Big Bang started everywhere rather than at one point.³ So within this narrow range of focus one has the sense that when looking at the universe or world as a whole it seems to embody a deep conflict that is only resolvable by an appeal to a geometric space one dimension larger than what one might have commonly supposed.

Regardless of the vast difference between the two ways of knowing that support these two remarkably similar views, I believe that noting this similarity may be of great use in an understanding of consciousness. In this scientific and moral-mythic view might there be a common mechanism? One wonders whether this "adding-of-a-dimension" isn't some sort of tour de force capability of the human brain to integrate otherwise contradictory understandings, even those embedded in complex collective ways of knowing. Could it be that the reason why these two views--grounded in such different ways of knowing and the worlds that they invoke-are so similar is because something similar is occurring in the brains that "contemplate the truth" of these views? Is there a neural architecture in the structure of the brain itself that is, through providing its "conflict resolution" services, leaving its footprint on these perspectives?

Stereopsis

Pursuing two ways of knowing is like looking with two eyes in order to perceive the world in depth. Now I would like to bring into this discussion one of the known mechanisms in the human brain for depth perception, stereopsis. Stereopsis is the term used in the scientific investigation of vision for the ability of the visual nervous system to discriminate the relative distances of objects by virtue of the positional incompatibilities, or disparities, between the objects as seen by the two eyes. This works within a range of distance near to that at which the two eyes are focused. Objects which lie outside of this "Panum's area" of focus appear as displaced double images (Matlin & Foley, 1997). To experience this doubled image simply focus your eyes at a distance and hold up your finger close to your eyes. You should see two fingers coming from two hands where you know that view of the world only contains the one hand (assuming your other hand is out of sight).

One can literally experience the apparent creation of depth by one's own brain by virtue of stereopsis performed upon two flat images. I have provided figure one in order that you may have this experience now.⁴ Place a notecard perpendicular to the page along the dotted line. Place your forehead against the near edge of the card. Now focus your eyes such that the two images overlap. You should perceive that the inner rectangle seems to lie in front of the outer one as if you were looking down onto a two layer, rectangular pyramid. Looking at the images without the notecard and without crossing your eyes reveals again the existence of two flat pairs of rectangles. The inner rectangle is in a slightly different orientation in each pair. When you cross your eyes until the two separate images seem to overlap, the visual nervous system automatically interprets the disparity between the two inner rectangles as the disparity between the image your eyes would normally detect for an object closer than the outer rectangle. While the two outer rectangles line up nicely as if they are in focus, the relative incongruity, or disparity, between the positions of the two inner rectangles is interpreted by your brain as a single, closer rectangle. ⁵ The brain assumes, at a "lower" perceptual level, that the contradiction in the position of the two rectangles is due to distance rather than the fact that each eye is looking at a different illustration, which you know, at a "higher" level of awareness, is the case.

The question that neuroscientists exploring stereopsis attempt to address is "How does the brain match up horizontally disparate visual objects?" In other words, how does the brain know to take the two different inner rectangles in figure one and make them into one? The earliest levels of visual processing in the visual nervous system rely on a response to a change in color (hue), brightness (bright or dim) or lightness (black, gray or white) within a small "patch" of the visual scene (Matlin & Foley, 1997). These edges or contours serve as the lingua franca of all subsequent neural discrimination (in a bottom-up view of neural "computation"). As figure one shows, simple line drawings with their simple lightness edges (the edge being between the region of black within the line and the white paper on either "side" of the thickness of the line) are sufficient visual information to support an experience of depth. By showing such simple, idealized visual stimuli, the mechanism of depth perception can be concisely explored in a scientific fashion. Measurement of individual neurons in the cortex of cats (Ohzawa, DeAngelis & Freeman, 1990; DeAngelis, Ohzawa & Freeman, 1991) and owls (Wagner & Frost, 1993) has revealed that specific neurons send impulses in the presence of edges that don't spatially match up when the visual scene as seen by both eyes is compared. ⁶

Stereopsis in More Depth

Are these disparity sensitive neurons the neural correlate of our conscious experience of depth? And are these neurons somehow involved in the vision of Black Elk or the science of Steven Hawking or the meaningful relationship between the two? Lets consider the first question first and from the point of view of the neural mechanism isolated from the world that provides the sensory stimuli. In the back of each eye there lie the nerve cells that are able to respond to the presence of light. These cells are the first layer of two succeeding layers of nerve cells in what is called the retina. A neuron in the first layer responds to the presence of light by sending nerve impulses (a wave of electrochemical energy) down along its axon (a long extended arm of the cell that physically touches other nerve cells). These impulses influence the electrochemical state of the next neuron in the next layer. This may cause neurons in this layer to send their own impulses to the cells in the third layer. The neurons in the second layer do not respond directly to the presence of light, only to the impulses from the neurons that do. The neurons in the third layer, if they are caused by sufficient influence to send impulses, do so through long axons that eventually reach all the way to the back of the cerebral cortex in an area known as the primary visual cortex. ⁷

The cerebral cortex as a whole, like the retina, is a two-dimensional layer-cake of neurons. This layer cake is composed of functionally distinct pieces, such as the primary visual cortex. These areas can be found to have special inner structures as well as a general pattern of connectivity to other pieces of the cortex and the brain in general. The primary visual cortex is an area where sensory information from the eyes first reaches the cortex. Also, it is the first place in which impulses originating from both eyes may influence a single neuron. Hence, this is the "lowest" layer in which we may expect to find neurons that are sensitive to horizontal disparities. This is where such neurons have been found (Ohzawa, DeAngelis & Freeman, 1990).

The images that the world presents to us fall upon the retina just as light falls upon film in a camera. The neurons receive focused light from a specific portion of the whole field of view in such a way that a miniature "map" of the scene illuminates the neurons in the back of the eye. It is the case that the earliest layers of neurons preserve this "map" of the visual image in that those neurons in the first layer tend to only influence correspondingly positioned neurons in the second layer. In this way, the map of the scene as seen by one eye is preserved to a large extent all the way to the primary visual cortex where neurons involved in depth perception are first to be found. In fact, other areas of the brain contain their own maps, some of the visual scene, while others, such as the motor cortex, may contain other maps. The motor cortex contains a map of the muscles along the bodies' surface(Zeki, 1993). There is a one to one correspondence between these maps and locations in the extra-neural world. This is how information about the relative spatial position of objects in the world can be preserved in the deeper layers of neural activity beyond the sensory neurons. Other regions of the brain have seemingly less coherent maps, while still others do not seem to have maps with any one to one relationship with the world external to the nervous system at all.

Neurons in the primary visual cortex that respond to horizontal disparities ⁸ are arranged in a kind of accurate map of the visual scene. This map is composed of the two accurate maps arriving from the two eyes. The area of overlay between these two two-dimensional maps is large. Within this area of overlap horizontal discrepancies in the location of edges abound when a three-dimensional scene is being observed. The disparity sensitive neurons may be seen as a third map that creates a map of the presence of a third dimension. In other words, the activity of these neurons signifies that instead of two contradictory two-dimensional worlds, there are two incomplete two-dimensional views from which one may extract information (horizontal disparities) and with this third map construct a three dimensional view that is complete.

Are there other maps of the discrepancies found between two similar maps? It was found that the disparity-sensitive cells in the visual cortex of the owl operate analogously to disparity-sensitive cells in the owl's auditory cortex (Wagner & Frost 1993). The same mechanism, as in vision, of a disparity-sensitive map of two similar maps is used in a different sensory modality, namely hearing. Yet whether light-sensitive neurons or sound-sensitive neurons originally drive the signals is irrelevant to the neural mechanism considered in itself. Neural impulses are neural impulses. Neurons connected to the eye are no different in any qualitative sense than those connected to the ear. In a nerve impulse there is no sense of sight or of sound. Apparently it is a matter entirely of the context in which the neuron fires and its particular, physical connectivity that says everything about its role in our conscious experience.

We may experience depth as a visual quality, but we also experience it as an auditory one. If the neural architecture is basically the same for these two kinds of conscious experience are we then to understand them as identical? Is there any difference between visual and auditory depth perception? Clearly there is if we consider the sensory modality in which these two kinds of depth perception are based for one participates in an entirely different world than the other. These are the worlds that have never existed if you are either congenitally blind or deaf. Yet both worlds have something to say about depth. In both the worlds of sight and sound there is an experience of depth embodied in the whole context of the world as "seen" through that sensory modality. Here we have an analogue for my understanding of how different ways of knowing may share differing perspectives on common features of the world. I suspect that a full understanding of consciousness is no different in this respect and with two eyes-ways of knowing focused upon it, qualitatively more satisfying answers to its mind-body problem can be had.

Linking Back

If stereopsis, a means for which the depth of the world is made known and tracked in the brain and the mind, is based on disparity sensitive neurons connected to two maps of the same visual world, and this basic disparity sensitive architecture is utilized in a completely separate cortical region and sensory modality, then just how much more use has evolution made of this neural architecture? If the cerebral cortex is largely partitioned into maps then would there not be plenty of opportunities to use this strategy. And might not higher levels of consciousness make creative use of this equipment of the brain to resolve problems in perspective in the mind?

Both Black Elk and Stephen Hawking's perspectives can be seen to be rooted in a visual context. Black Elk spoke of seeing something. Though what he saw may not have been a physical manifestation in the world, it was no less important as a creative product of mind and spirit. Stephen Hawking referenced the mathematics of spatial geometry in his description. Is a lower-level visual process not potentially involved here? If Stephen Hawking had a language to precisely express what Black Elk struggled to express, what does this imply?

In my case Stephen Hawking's view of the universe had helped me to understand what and, possibly, how Black Elk's vision may have come about. Beside being a member of his culture and a recipient of its insights and struggles, Black Elk's mind was receptive to struggling with the greatest issues and found a solution. This may have come about as I have suggested because the resolution into a third dimension of a problem may have support in neural architecture. That this was even relevant I realized via contemplating why Stephen Hawking and Black Elk might come to say the same thing about the center of the universe. That this could be what Black Elk saw is just as likely as Black Elk understanding that the world has depth without having to know the Cartesian coordinate system. The Cartesian coordinate system just gives us a separate way of knowing depth that allows Stephen Hawking and his culture to extract more knowledge of another kind about the shape of the universe as a whole.

On the Other Hand�

Any photograph of some portion of our spacious world will show how a two dimensional image--that cannot give disparity cues necessary for stereopsis to occur--can provide us with a sense of depth. The presence of objects that cover other objects, the relative size of similar objects or of objects with expected relationships in relative size, the convergence of parallel lines, the atmospheric bluing of distant objects and shading all provide information about the distance of objects and give us a sense of the depth of the world (Matlin and Foley, 1997). But these observations are certainly embodied in a different, though not necessarily unconnected, neural architecture than what we have considered is the architecture of stereopsis. If the existence and activity of stereoscopically discriminate neurons were the neural correlate of the perception of depth, then the sense of depth we get from a photograph would remain unexplained. It seems that no such simple relationship exists between the piece of our phenomenological experience we call 'depth' and our scientific insight into disparity-sensitive maps of other comparable neural maps. Even as we find an architecture analogous to stereopsis in other sensory modalities, we also find within vision that depth is a function of more than one kind of neural architecture.

In the natural world the variety of features that our eyes seem to use as cues to depth are often present in all their variety. It is only with the discriminating intelligence of human beings with our cleverly constructed, abstract visual scenes that we are subject to visual stimuli of a less complex and varied nature. Viewing situations such as in figure one are certainly new to the experience of our evolutionarily adapted eyes and the brain that makes use of them. In a similar vein, we cannot expect to find that depth has as simple a neural correlate as a bottom-up approach to understanding neural activity would potentially imply that it might. Our brains have adapted to the natural world and not to the artificial one's that scientists might use to test a theory. The natural multiplicity and complexity of our environment is at once a source of opportunity and frustration in understanding how we "understand". The mechanisms we uncover in the brain are mechanical (in the broadest sense), but they are always as such embedded in the brain whose very appearance and intercellular connectivity suggests the multiplicity, diversity and complexity of the world it tries to track.

In this far-reaching gathering and comparing of perspectives through which this paper has meandered, we have had cause for insight and then disillusion. A series of constructed and deconstructed perspectives leaves us on uncertain ground as to the value of the speculation we have just pursued. But, as I have stated, if there is no ultimate perspective, no universal frame of reference, then this is precisely what one would expect at the nearest approach to truth on such matters! Approaching the center of any element of consciousness, a qualia, will, like consciousness itself (and other "whole" words like universe, life, and God) will bring us to the brink of an unreachable place. The unreachable place is the perspective beyond the whole, the perspective which explains why there is a "why". It brings you to the perspective beyond perspective which makes no sense in any way of knowing. The center is the circular knot that is ever untied but never completely; a direction we are to orient toward but not a destination to reach.

The trick then, in trying to grasp consciousness, is not to insist on reaching the destination, but to learn how to orient yourself toward it and to experience "what it is like" to make an approach to it. By approaching the center (of the nature of consciousness) with two ways of knowing, but, at the same time, respecting a certain distance, you have a methodology that allows you to "see" that you are approaching the center and see where you are still a ways off. This is because each way of knowing serves as a frame of reference for the other way of knowing. This, of course, is not the intended use of these two ways of knowing, but, as a human being with consciousness we can choose to put the two ways of knowing into relationship, even in spite of protests from within each community that supports that way of knowing.

What is left?

So what are we left with in this case? What sort of an answer have I provided? The answer to this question is that I have provided an answer with more depth than others that have been given. My answer is composed of that momentary experience of significance, the closely-following experience of ambiguity and the continual pattern of repeating, building perspectives that both individually and progressively construct and deconstruct the attempt to understand the stated problem. There is no central thesis here, just the creation of a wider space for truth. The perspectives seem to both connect to and yet be of the most distant relationship with the rest of the perspectives. Rather than a focused answer I have endeavored to creatively loop an array of signficant and ambivalent perspectives with as strong an appeal to objective knowledge as possible. I expect I could have continued this paper indefinitely continually fleshing out further associations and looping them back in. I could have started with an endless variety of focal ideas instead of depth and the shape of the universe. Is this story-telling or analytical thought?

Actually what this may qualify as is symbolic thought. Jung developed the idea that the unconscious depths of our psyches produce images with an import beyond conscious mastery. These images, these symbols, radiate from their numinous centers conflicting notions that all center around the central symbolic idea or image. Symbols reflect the underlying universals (archetypes) of our collective inherited mind-brain. They represent evolved channels of psychic relationship and meaning that re-express themselves in each of us individually albeit to a varying creative extent. This essay represents an attempt to express a symbol in written form. If this essay were an illustration it would be one which incorporated the notion of universe, center, two eyes, depth. Some abstract illustration could likely be made to illustrate this, but since this was not the starting point for this exploration, I do not have an illustration to provide ready at hand.

The answer to an understanding of consciousness is then to give expression to symbols and interpret them. When the content of the symbol contains the topic of consciousness in a vital way, then the symbol can be said to address the nature of consciousness. The way to unravel a symbol is to be first caught by one then follow out a train of associations. Gathering those associations and then amplifying their context with respect to the original image, considering them in their relationship to each other and in relationship from the collective way of knowing from which they originated should produce roughly what I have tried to produce here.

Footnotes

¹This may sound circular but the answer must come out of the personal creative activity of the individual knower as much as it comes from the contemplation of knowledge being passed on to him or her.

²Remember that the center of the Earth, its molten core is not a valid answer because it does not exist on the surface of the Earth. The Earth's surface is to be thought of as a flat two-dimensional place, the Earth, as a whole, is a sphere in three dimensions. Black Elk's Earth was, presumably, the flat one.

³With no new points having been created in the meantime.

⁴This figure is basically an alteration of the one shown in Demonstration 6.4 in Matlin and Foley (1997).

⁵To help make this more clear simply hold up one of your fingers about a foot in front of your eyes. Close one eye and notice with the other where your finger lies in front of the more distant wall or landscape behind it. Now close that eye and open the other and you should notice that your finger would have seemed to switch positions relative to that same background. Now you should make the connection between your finger and the inner rectangle and the background and the outer rectangle. Objects at different distances from your two eyes will give each eye a different picture of the world in terms of objects being located in slightly different relative positions.

⁶The reader should be aware that no neural input, originating in response to light falling onto light sensitive nerve cells in the eye, is received from both eyes by any neuron until that "signal" has passed through several "layers" of nerve cells that "process" the original stimulus to some extent. In other words, nerve cells in contact with binocular information are not on the "front-most line" of neural excitation due to sensory input.

⁷For the sake of simplicity and brevity I have omitted the sideways projections in the retina and the important intermediate layer of neurons in the lateral geniculate nucleus, a structure midway between the retina and the primary visual cortex.

⁸Why horizontal? Because it is the horizontal difference between the two eyes that makes for the horizontal disparities in the objects they perceive. There are neurons with vertical disparity sensitivity but they are much smaller in number.

References

Chalmers, D. (1995), 'Facing up to the problem of consciousness', Journal of Consciousness Studies, 2, No. 3, 1995, pp. 200-219.

DeAngelis, G. C., Ohzawa, I., & Freeman, R. D. (1991) 'Depth is encoded in the visual cortex by a specialized receptive field structure', Nature, 352, 11 July 1991, pp. 156-159.

Descartes, R. (1968), Discourse on Method and the Meditations Sutcliffe, F. E. (trans.), (London: Penguin)

Hawking, S. (1988), A Brief History of Time (Toronto: Bantam)

Jung, C.G. (1971, 1921), Psychchological Types Baynes, H.G. (trans.), Hull, R.F.C. (rev. trans.) (Princeton, NJ: Princeton University Press)

Matlin, M. W. & Foley, H. J. (1997), Sensation and Perception (Boston: Allyn and Bacon)

Neihardt, J. G. (1932), Black Elk Speaks (Lincoln: University of Nebraska Press)

Ohzawa, I., DeAngelis, G. C., & Freeman, R. D. (1990), 'Stereoscopic depth discrimination in the visual cortex: neurons ideally suited as disparity detectors', Science, 249, 31 August 1990, pp. 1037-1041.

Wagner, H. & Frost, B. (1993), 'Disparity sensitive cells in the owl have a characteristic disparity', Nature, 364, 26 August 1993, pp. 796-798.

Zeki, S. (1993), A Vision of the Brain (Oxford: Blackwell Scientific Publications)

The Mind-Body Problem Home e-mail me The Depth of Consciousness (01-19-2006)

Hosted by www.Geocities.ws