Psychological Physiology From the Standpoint of a Physiological Psychologist
by George Wolf
George Wolf is Research Professor of Physiological Psychology at New York University, New York. The following article appeared in Process Studies, pp.274-291, Vol. 11, Number 4, Winter, 1981. Process Studies is published quarterly by the Center for Process Studies, 1325 N. College Ave., Claremont, CA 91711. Used by permission. This material was prepared for Religion Online by Ted and Winnie Brock.
"Consciousness is a sort of public spirit among the nerve cells."
-- Peirce, quoted by Hartshorne
I have been preoccupied for a long time with the question, "How is our conscious experience related to our bodies?" The answer I am looking for involves more than knowing what experiences are correlated with what physiological events. It involves understanding how they are correlated. Recently I learned of Whitehead’s concept of psychological physiology. Here is an interesting way of envisioning the correlation -- a way that is radically different from that of ordinary physiological psychology and yet compatible with scientific knowledge. The main difference between these two approaches is reflected in the order of the terms that name them. Whereas physiological psychology assumes that experiences are the outcome of physiological events (physiology comes first), psychological physiology assumes that physiological events are the outcome of experiences (psychology comes first).1
There are two other notions in Whitehead’s cosmology that are relevant to this topic. First, subjective experience is not limited to animals. The elementary particles that make up the world and possibly other things such as molecules and cells are sentient individuals too. Second, in its essence, experience is not continuous through time. Although it may seem like a flow, it is made up of a sequence of discrete actual occasions -- acts of experiencing. Each occasion of private, subjective experience becomes a public, objective event -- the superject of the experience.
In this new framework my question takes a different form: What are the properties of conscious superjects? More specifically, what kind of physiological event does an occasion of human conscious experience become? If the answer is to be in line with Whitehead’s cosmological scheme, it will have to take account of the idea that conscious occasions are a subclass of presiding occasions -- actual occasions that dominate a physical system so that it functions as an individual rather than as an aggregate.2 But my ideas about what the features of presiding superjects should be are not exactly the same as Whitehead’s. This is because I have been influenced by modern holistic approaches, by Hartshorne’s version of process cosmology, and by research in the life sciences. Therefore, I will precede the discussion of conscious superjects with a more general discussion of presiding superjects.
The first section of this paper presents a general cosmological theory that applies not only to human conscious superjects but to presiding superjects of any kind of individual. I try to bring together the notions of hierarchical nesting, forms of relatedness, physical fields, and interstitial spaces in models of the general features of presiding superjects. The models depict three types of features -- spatial, temporal, and dynamic. The resulting picture is different from the one Whitehead presents in PR, but I believe it is the kind of picture he was approaching in his later work.
In the second section I formulate an empirically testable theory of the physiological correlates of conscious experience. This theory unites the spatial, temporal, and dynamic features of presiding superjects in the hypothesis that a conscious occasion becomes a configuration of waves in the electrical field of the brain.
A Cosmological Theory of Presiding Superjects
What might be the size, shape, and bodily location of conscious superjects? It seems that Whitehead envisioned them as being tiny in size and located in the interstitial space of the brain. "The final percipient route of occasions is perhaps some thread of happenings wandering in ‘empty’ space amid the interstices of the brain" (PR 339/516).
How did Whitehead come to this extraordinary notion? According to one interpretation of his theory, actual occasions become minute objects which are packed one next to the other in space (empty space being filled by "occasions of empty space"). This depicts a world made up of momentary building blocks -- sort of a three-dimensional mosaic of actual occasions.
Apparently this "mosaic model" of the world grew out of Whitehead’s earlier work in physics. There, following contemporary physical theories, he thought of the world as a plenum of infinitesimal event-particles. Later he reasoned that these event-particles should have subjective features as well as objective features -- viz., actual occasions. It seems that, at least in the early stages of his theory, actual occasions still had the spatial features of event-particles. Since a moment of human experience is an actual occasion, each moment must become something tiny like an event-particle.
It is not clear how closely Whitehead held on to this image in his later thinking. But, as I understand his theory of extension in PR, the following rules hold for the spatial relations among actual occasions, and I find no evidence of later modifications of these rules. (A) There are no regions of space that are not occupied by actual occasions. (B) Contemporary occasions do not overlap. (C) One occasion cannot completely surround another occasion.3
These rules do not entail a mosaic model, but in any case, I think the mosaic model is unnecessarily restrictive -- presiding superjects should range in size and shape just as individuals do. To begin with, the mosaic model is discordant with the theory of societies that Whitehead outlines in PR. The theory of societies, like modern general systems theory, pictures a world made up of societies within societies (systems within systems). That is, societies do not just line up side by side like mosaics -- they form "nested hierarchies" that go from subatomic particles through cells to animal bodies, or through stars to galaxies.
The discordance between the mosaic model and the theory of societies is especially clear in the case of an animal body. We presume that some of the subsocieties of the body, such as cells and atoms, attain moments of individuality just as the whole animal does. This means that there are times when these subsocieties have their own presiding occasions. According to the mosaic model presiding occasions of bodies, cells, and atoms are all about the same size and are packed one next to the other in space. How can this be when the societies that these occasions preside over differ so greatly in size, and the smaller societies are nested inside the larger ones?
Another thing to consider is that our experience is a holistic phenomenon that involves the integrated functioning of the whole body. Also, we ordinarily feel embodied. I think that a spatial model should reflect these facts -- the superject of an experience should permeate the body like a "public spirit" that fills the spaces among the cells. In fact, the concept of an interstitial space is especially relevant to this holistic line of thought. In his Gifford lectures of 1922, the great comparative psychologist C. Lloyd Morgan spoke of the emergent unity of an individual as a "form of relatedness" among its parts.4 It seems reasonable to think of the interstitial space between the parts of a society as being the locus of the occasion (the form of relatedness) that unites these parts. But to unite the whole society the occasion should fill the whole interstitium, not just one part of it.
I think these are good reasons to develop a new model which has the following features. First, presiding occasions fill the whole interstitial space of the society over which they preside. Second, this space is coextensive with the society itself. Third, presiding occasions of subordinate societies are nested within presiding occasions of superordinate societies. It turns out that it is possible to transform the mosaic model into a "hierarchical model" with the above features without violating the rules of no empty space, no overlap, and no surrounding. I will describe this model and show how it corresponds to the actual anatomical structure of organisms.
Consider the following model of an animal body. Picture a jar full of marbles (the marbles representing the body cells). Imagine pouring a liquid into the jar to fill the interstitial space between the marbles. Imagine further that the liquid solidifies, so that the containing jar itself can be removed, and we are left with a kind of sponge structure packed with marbles. Note that the sponge -- the interstitial stuff -- does not completely surround any marble because each marble touches several adjacent ones. Note also that there are no overlapping regions and no empty spaces.
Now, the sponge-marble structure can be applied to successively lower levels of the animal body. Just imagine each of the marbles (cells) to be, itself, a miniature sponge packed with miniature "secondary" marbles (molecules) which are themselves sponges, and so on. In this kind of nested hierarchical structure no region is ever completely surrounded by any larger region -- topologically everything is side by side just as in the mosaic model. As a matter of fact, the very tiniest region deep inside the structure is actually outside the structure in the same way that any object in the hole of a donut is outside the donut.
How closely does this model correspond to the structure of an animal body? Like the marbles, body cells generally connect with each other at several points along their surface so that the space between them has the topological properties of the above sponge structure. This interstitial space is literally the extracellular fluid compartment which functions as an internal environment for the body cells -- the milieu intérieur of Claude Bernard.5
At the cellular level there is something like an interstitial space between the structural proteins that make up the cell walls around and within the cell. Moreover, the adjacent proteins are connected by molecular bonds so that the space does not surround them. The lower we go the more uncertain we are of the actual structure. But, it seems that the data are compatible with the conjecture that there are similar connections and spaces at lower and lower levels.
Thus, it seems possible to transform the mosaic model to one in which presiding occasions permeate the society over which they preside by occupying its interstitial space. This hierarchical model has the advantage of being congruent with the theory of societies and with the notion of holistic emergence. At the same time it seems to be in accordance with Whitehead’s theory of spatial extension.
There is, however, one important feature of the mosaic model that is lost in the hierarchical model. This is the simple notion of an actual occasion as a perspective on the world. This notion is captured in the image of a time-cone which terminates in a punctate region. I believe that this notion can be incorporated into the hierarchical model by an additional elaboration. Imagine that every actual occasion, no matter how large, has a kind of center of gravity -- a "center of experience." Imagine a focus of intensity at this center and then a gradual fading off towards the periphery. This focal point can be conceived of as the origin of the perspective -- the tip of the time-cone.
There are other advantages to this elaboration. The idea that conscious superjects have a central focus matches my normal impression that although I pervade my whole body my mental processes are largely centered in my head. It is possible that different feelings of personal location are associated with different foci of conscious superjects. Also, the foci of successive superjects can be identified with Whitehead’s "thread of happenings" that wander from one part of the brain to another according to where the "greatest intensities of feeling" are to be found. This idea fits what we know about localization of function in the brain -- different mental functions involve different regions.6
What might be the duration of a conscious superject? (I use the term "duration" here in the ordinary sense of a stretch of time rather than in Whitehead’s technical sense of a cross section of the universe.) This question presupposes Whitehead’s theory of epochal time, which has many difficult problems. I will have to bypass some of them here in order to focus on those that are most relevant to this study.
The theory of epochal time states that the genesis of an actual occasion does not take place in physical (clock) time; it creates a quantum of physical time: in every act of becoming there is the becoming of something with temporal extension; but that act itself is not extensive, in the sense that it is divisible into earlier and later acts of becoming which correspond to the extensive divisibility of what has become" (PR 69/107).
I take this to imply that a superject occupies a particular region of space and time which has a definite magnitude and a definite relation to other regions. Therefore, one can say that during a given period of clock time a particular region of space was occupied by a particular superject. But Whitehead does not explicitly distinguish this finite period of objective presence from the endless period of objective existence which follows the concrescence of an occasion. "An actual entity is to be conceived both as a subject presiding over its own immediacy of becoming, and a superject which is the atomic creature exercising its function of objective immortality" (PR 45/ 71).
It will be helpful to distinguish a "period of superjective presence." This is the period of clock time during which the superject occupies its particular spatial region. I will assume, on the basis of Whitehead’s principle of process, that the period of superjective presence corresponds to the subjective duration of the occasion (its specious present or presented duration) in some sense or another.
What I want to discuss in this section is the idea that the duration of a superject is correlated with its size (i.e., its hierarchical level in a structured society). Imagine a progression of superjective durations that corresponds to the progression of superjective sizes as one ascends a hierarchy such as the one that makes up an animal body. In this image, there is not just spatial nesting but spatiotemporal nesting in a structured society.
As far as I know, Whitehead does not directly address the question of whether there is a progression of durations. But some of his metaphors suggest that his thought was moving in this direction. In PR he identifies subatomic occasions with events which are only millionths of a second in duration. "Thus, there is every reason to believe that rhythmic periods cannot be dissociated from the protonic and electronic entities" (PR 79/ 122). Also, he seems to have considered the possibility that different types of occasions differ in duration. "The factor of temporal endurance selected for any one actuality will depend upon its initial ‘subjective aim’" (PR 128/ 195). But he says nothing about durations of higher grade occasions in PR, and there is no evidence that he thought of them as being much longer than subatomic occasions at this time. However, in later works he begins to speculate about the actual durations of higher grade occasions and suggests that human conscious occasions have a duration of some tenths of a second.
But our immediate past is constituted by that occasion, or that group of fused occasions, which enters into experience devoid of any perceptible medium intervening between it and the present immediate fact. Roughly speaking, it is that portion of our past lying between a tenth of a second and half a second ago. (AI 181)
This second source [of our immediate experience] is our own state of mind directly preceding the immediate present of our conscious experience. A quarter of a second ago, we were entertaining such and such ideas, we were enjoying such and such emotions, and we were making such and such observations of external fact. In our present state of mind we are continuing that previous state (MT 219f.)
Perhaps Whitehead was beginning to envision a vast progression of durations correlated with the progressing complexity of occasions. It seems reasonable to suppose that higher grade occasions have longer durations. First, a longer duration seems more suitable for a richer experience -- one that appreciates more of the past, involves more phases of integration, and sees further into the future. Second, empirical data show that, generally, the larger an event, the longer its duration.7 Given that higher grade occasions are larger than lower grade occasions, it follows that their durations should be longer.
Once the notion of varying durations is adopted, great new possibilities for speculation are opened. One can consider the possibility of macrocosmic occasions that last minutes, hours, or eons. Also, the idea of a progression of durations brings a certain aesthetic harmony to the theory of societies by unifying the variables of size, duration, and complexity across the levels of hierarchies.
On the other hand, the notion of a progression of durations raises some difficult problems. Perhaps this is why Whitehead did not speculate much here. But, I believe that these problems arise with any theory of durations that allows for any variation at all. The problems are just more obvious when the durations are long and the variations are large. For example, it is difficult to work out a plausible scheme of prehensive relations when durations differ greatly. Imagine the prehensive relations across levels of a structured society in which presiding occasions have durations a million times longer than do subordinate occasions. Other problems arise that involve relative motion, or more generally, relative change. In the cosmological scheme of PR actual occasions do not move. Change is "the difference between actual occasions comprised in some determinate event" (PR 73/ 114). This creates problems when durations vary. How do long-lived, motionless actual occasions keep their place in a society that is in motion? For instance, a person can move a considerable distance in a tenth of a second -- where is the motionless conscious superject that came into being here, when the body is now there? Can we think of the spatiotemporal region between here and there as a static quantum? I will return to these problems later.
How might conscious occasions interact with other occasions of the body? The empirical data tell us that neurons are the functional units that carry sensory information from the body into the brain and carry effector information from the brain to the body. If conscious occasions are to play a role in the activities of the body, they must interact with neural occasions. Now, neural impulses are very brief compared to actions of the whole body. A neural occasion could not be much longer than a thousandth of a second without extending over more than a single neural impulse. How can we conceive of the prehensions between conscious occasions and neural occasions?
Given the kind of spatiotemporal progression that I have described, one might envision the interaction between presiding and subordinate occasions as follows. Imagine a presiding occasion to be like an ambient environment for subordinate occasions -- something like our atmosphere is to us or the extracellular fluid is to body cells. There are many different types of changes in an ambient environment -- some very fast like electromagnetic waves, some very slow like the accumulation of pollutants in the air, and some with rapid onsets and offsets but long durations like a rainfall. Let the slow or long-lasting ambient effects represent the acts of presiding occasions. So a presiding occasion is analogous to a context which sets the conditions for life within it. The action of a presiding occasion constitutes a change in the context which produces a change in the individuals within it.
On the other hand, individuals can change the context which defines them. For instance, our short-lived acts can have cumulative effects upon our atmosphere -- each breath we take changes its composition a little. We can actually see our effect on an atmosphere in a small enclosed space -- imagine a room filled with cigarette smoke. Also, it is well-known that body cells alter their extracellular environment by exchanging chemicals, generating heat, and so on.8
The analogy uses ordinary physical interactions to illustrate the interplay between a slowly acting, overarching individual and the myriad of quickly acting individuals which make up its body. This raises the question of how to conceive of physical interactions involving living occasions, such as conscious occasions. To be consistent with scientific thought, conscious superjects must have physical properties if they are to have physical effects upon the body.
Whitehead’s speculations about living occasions do not directly address this issue. He was concerned mainly with the problem of reconciling novelty and endurance. He felt that physical structures were too inflexible to allow for the originality that characterizes life. This is why he speculated that conscious occasions occupy the interstices of the brain: "life is a characteristic of ‘empty space’ and not of space ‘occupied’ by any corpuscular society [i.e., material body]" (PR 105 / 161). He suggested that living nexus are characterized by conceptual rather than by physical properties.
But not all physical things are rigid enduring objects like corpuscular societies. Societies of waves (modulations of physical fields) do not have a static structure, and so they seem quite compatible with conceptual novelty in this regard. It is interesting that Whitehead associates physical fields as well as living nexus with empty space (PR 92/ 141). In any case it seems reasonable to identify presiding superjects of physical societies with the physical forces or fields among the subsocieties. What I want to suggest here is that conceptual as well as physical prehensions are manifested physically in conscious superjects. This notion expresses what most neuroscientists believe -- that there is a one-to-one correspondence between mental events and brain events.
There is one more dynamic feature which needs to be discussed. I have not yet accounted for the agency which characterizes individuals. An adequate theory of the interaction between presiding occasions and subordinate occasions should account for our feelings of personal causal efficacy over our bodies.
Critics like Paul Weiss have argued that the inertness of the actual world in Whitehead’s scheme is incompatible with real individual action upon the world.9 There are now two problems associated with the inertness of superjects -- the problem of action and the problem of relative motion which I mentioned in the preceding section. Is it essential to Whitehead’s cosmology that superjects be dead facts? Let us see what happens if we "activate" the superject. In other words, consider the idea that motion, and more generally any kind of activity, is just another species of eternal object that ingresses into actuality along with others such as shape and color. This activity should occur during the period of superjective presence which I distinguished before. Thus, an actual occasion has a sort of power during this period that it does not have during its genesis or during its subsequent objective immortality. In Weiss’s terminology one might say that an occasion insists on itself" during this period so that it cannot readily be eliminated from feeling by negative prehensions. But to say that it insists on itself does not mean that it is simultaneously an experiencing subject -- the insistency of the superject can be thought of as a Sort of after-effect of the subjective aim.10
This modification of the theory of actual occasions fits Whitehead’s observation that in the present cosmic epoch "direct objectification is practically negligible except for contiguous occasions" (PR 308/ 469). The period of superjective presence is precisely this period of contiguity -- the time that the superject is available for direct prehension. After this time the superject is prehended only indirectly through intervening occasions. This is evident in ordinary life in the sense that present events have a kind of insistency that past events lack. I can more or less disregard things that happened in the past, but I cannot readily disregard a present stimulus like a loud sound or a shove from behind.
Another advantage of the idea that superjects are mobile is that some of the problems of relative motion are avoided. For instance occasions can maintain their relative positions in a moving society. (But some additional assumptions would also be needed to account adequately for relative motion.)
Now we must look at the new problems that this modification raises. The theory of epochal time implies that quanta of physical time come into being "in solido." That is, in some sense, each chunk of time comes into being all at once. This might be understandable if the chunks are conceived to be static entities. But how can we conceive of a dynamic superject in these terms -- how can a trajectory of change come into being in solido, all at once, the end along with the beginning? Suppose this is a relatively long duration -- will short-lived occasions concrescing at the beginning of the duration prehend the same features as those concrescing at the end of the duration? I do not know how to answer these questions.
It may be helpful to summarize the alternative solutions to the problems of time and dynamics that came up here. First of all, one can avoid the problems of relative motion by reverting to the idea that all actual occasions have the same brief duration. However, this does not solve the problem of action, it is incongruent with the theory of societies, and it gives me a very implausible account of my experience. If one opts for varying durations instead, one must account for the coordination of motion within and between societies. I cannot imagine any way to do this other than to assume that superjects do move. This has the added benefit of solving the problem of action, but it implies that a trajectory comes into being all at once -- a very questionable idea. Since none of the alternatives is satisfactory one might consider abandoning the theory of epochal time altogether. But then one will have to confront the problems of freedom and causality which the theory uniquely solves.
In summary, it seems to me that the trade-offs involved in the following choices are worthwhile -- epochal time over continuous time, varying durations over a uniform duration, active superjects over inert superjects. Although the remaining problems of the theory of epochal time are awesome, I see no reason to believe that they are insoluble. For instance, perhaps we do not have to think of one notion of time as more fundamental than another -- perhaps we can find ways of conceiving of epochal time and continuous time as basically complementary. This could greatly increase the adequacy of the theory.
A Neurophyslological Theory of Conscious Superjects
Features of Brain Waves
From the standpoint of physiological psychology one wants a theory of conscious superjects that can be tested by experiments. This means that general notions like those of the cosmological theory have to be tied to observable things or to hypothetical constructs which are measurable. Is there any conceivable physiological correlate of experience that has the spatial, temporal, and dynamic features that I have described? I do not know of any that exactly fits these features, but the electrical field of the brain (i.e., the field of "brain waves") comes very close. Also, it has several other attractive features. For instance, it has a unity that matches the unity of experience, and it is complex enough to code the contents of experience in a one-to-one manner. In fact, Wolfgang Kohler and other researchers in the holistic tradition have formulated theories that link conscious experience to brain waves." Let us see what a brain wave model of conscious superjects might look like.
According to biophysical theory the brain waves that are picked up by ordinary electroencephalographic (EEC) recording techniques are superimposed electrical potentials produced by large populations of neurons. Each synaptic event and each neural impulse cause a change in the distributions of electrically charged atoms in the adjacent interstitial fluid. This is reflected in local electrical potentials. When groups of neurons fire synchronously, the local potentials summate to form more widespread potentials. Thus, the electrical field is made up of complex patterns of waves upon waves.
The present theory of conscious superjects proposes that there is another independent variable that determines the pattern of brain waves. This variable is the self-creative action of conscious occasions. The superject of this self-creative action is a particular configuration of brain waves superimposed on the waves produced by neural activity. Now, let us see how well the spatial, temporal, and dynamic features of the brain’s electrical field match those of all presiding superjects.
Electrical potentials are generated throughout the brain. But there are also varying focal regions of activity. For example, the intensities and patterns of the brain waves in different areas of the cortex change according to the kind of mental activity that is going on. However, brain waves are not confined to the brain because the interstitial fluid functions as a conducting medium and it is continuous throughout the body. Cell membranes act as barriers to current flow into the cells, so the electrical field is confined to the interstitial space. The waves travel through this space at roughly the speed of light. They fall off sharply in amplitude with distance from their source in the brain (according to the inverse square law and the impedance of the medium).
One important complication here is that other body organs such as the heart also generate electrical potentials that spread through the body and summate with the potentials from the brain. Therefore, we should think of brain waves as making up just one component of a complex field of electrical activity -- presumably contributing certain characteristic frequencies to the field.
The predominant EEG frequencies are in the range of 3 to 20 cycles per second. It is interesting that these frequencies correspond so closely to the duration that Whitehead suggested for conscious occasions. However, there are many other brain wave frequencies that are not picked up in ordinary EEC recordings. These range from local "action" potentials in the millisecond range to "DC" potentials with durations of minutes or hours. Can we think of the longer potentials as representing single conscious occasions? Not easily. According to the theory of epochal time an occasion does not prehend contemporary occasions. An empirical implication of this is that a conscious occasion cannot be longer than the minimum conscious reaction time to a sensory stimulus. This reaction time varies with different states of consciousness, but it is typically less than a quarter of a second.12
A critical property that the brain’s electrical field should have is causal efficacy upon neurons. Recent research suggests that this is in fact, the case. An animal’s brain waves can be directly manipulated by placing it in an electromagnetic field and modulating the electromagnetic waves within the range of the brain’s natural rhythms. This procedure can alter both neural activity and overt behavior in the animals. Also there is evidence of molecular mechanisms in the cell membranes that can amplify small changes in the field to produce large changes in neural activity.13 On the other hand, earlier tests of Kohler’s theory found that interference with electrical gradients over the cortex had no effect on behavioral measures (see note 11 for reference to these studies). This and other negative findings will have to be accounted for before we can conclude that the electrical field does have the causal power that the present model requires.
Consider now some shortcomings of the brain wave model. First the uninterrupted flow of brain waves seems discordant with the notion that each superject is a distinct event. This problem is similar to that of reconciling the apparent flow of experience with the idea that it is made up of distinct acts. However, it is important to note that the brain wave model is pretty much compatible with other notions of time, including the ordinary notion of continuous time as well as the notion that time is made up of uniform infinitesimal epochs. As I noted before, each alternative has its own problems, and so this shortcoming of the brain wave model originates in the more general problem of time.
Second, it seems that the model does not correspond to Whitehead’s idea of what makes up electrical waves. He envisioned each electron to be a society of electronic occasions. So a single brain wave would involve many societies of electronic occasions. In contrast, the present model identifies a single conscious occasion with a whole pattern of waves. It might be possible to combine the two notions by thinking of conscious occasions as presiding occasions of the electronic society of the brain, but this involves additional confusion that would need to be cleared up.
Third, the model has the general limitations that beset any abstract concept. It treats parts as though they were wholes -- aspects of things as though they were complete and self-sufficient entities. In the present case, it is important that we do not lose sight of the fact that, in reality, there is no such thing as an electrical field that is separable from current sources, a medium, chemical gradients, heat, gravity, and so on ad infinitum. Also, the spatial boundedness of the field is a kind of fiction. The electrical field of the brain is continuous with the electromagnetic field outside the body. The brain itself is not simply located inside the body.
We cannot tell with what molecules the brain begins and the rest of the body ends. Further, we cannot tell with what molecules the body ends and the external world begins. The truth is that the brain is continuous with the body, and the body is continuous with the rest of the natural world. (AI 225)
I do not want to try to evaluate the strengths and weaknesses of the model at this point. Instead, let us look at some of its scientific implications.
What are the implications of the brain wave model for scientific theories and research? To begin with the model diverges from current theories of physical causality. According to process cosmology experience is the coming-into-being of objective reality. In the brain wave model conscious experience is the coming-into-being of a configuration of brain waves. To put it plainly, the model implies that the electrical field of the brain is affected by experience itself. But it takes energy to generate electrical potentials, and, according to biophysics, this energy can come only from cellular metabolism.
Some scientists accept the notion that experience affects body functions but try to formulate the problem in a way that does not involve conflicts with thermodynamic laws. For instance, general systems theorists have proposed that what is involved in such effects is modulation of the overall distribution of energy in a system and not the introduction of new energy into the system. There are many examples of emergent, overarching constraints that govern the interactions among the parts of a physical system and thus alter the distribution of energy within the system. But to account for the causal power of experience in terms of general emergent principles is not yet to explain how a free act of self-creation affects the distribution of energy in the brain. So, I think that there is no getting around that fact that if the present model were correct, it would call for some revisions in current ideas about the determinants of physical fields.
Consider now the experimental implications of the brain wave model. The model states that it is not just cellular activity that determines brain wave patterns -- the way a conscious occasion comes into being also affects the pattern. This implies that in the absence of conscious occasions, say when a person is unconscious, the correlation between neural impulse patterns and brain wave patterns should be higher than when the person is conscious.
A further prediction comes from the notion of mental originality. In accordance with the principle of process, the model implies that a novel idea will be reflected in a novel pattern of brain waves. Novel ideas (conceptual prehensions) are independent of physical data such as neural activity. Therefore, the brain wave pattern reflecting a novel idea should deviate from concurrent neural impulse patterns. The straightforward experimental implication is that the correlation between brain wave patterns and neural impulse patterns should be lower when a person is engaged in creative thought than when engaged in routine activity like adding numbers.14
Is it possible to test these hypotheses with current neurophysiological techniques? An ideal experiment would require monitoring the activity of all brain cells and all brain waves simultaneously. We are nowhere near being able to do this; however, current technology does let us sample the concurrent activity of small groups of neurons and their ambient electrical field. This is done routinely in experiments with animals and occasionally with human patients undergoing neurological treatment. Although no single experiment of this type would be conclusive, a series of experiments which all pointed in the same direction could be. As a matter of fact, E. R. John and his colleagues have been carrying out experiments of this type to test a model of consciousness that links consciousness to the activity of a particular type of neuron.15 It appears that John’s model predicts different results than the present model does, and one can think of several feasible experimental designs that would test between the two models. But what is most important here is the fact that researchers are actually testing models like the present one and getting relevant results.
Finally, I believe that these kinds of experiments can also test the validity of the present cosmological theory and of process cosmology in general. In other words, these very general speculative schemes are not entirely immune to empirical data. For instance, suppose that experiment after experiment showed that brain wave patterns deviate most from patterns of neural activity when people are making what look like free choices. Suppose further that no one is able to come up with a good explanation of this phenomenon in terms of biophysical principles. I think that most scientists would consider at least some of the notions of the cosmological theory as being more plausible in the face of such positive results. On the other hand, suppose experiments showed that every brain wave is associated with a neural substrate, and no deviation can be found under any condition. In contrast to the positive results, it seems relatively easy to explain such negative results away, and I cannot think of any other plausible negative results that would strongly disconfirm the cosmological theory. Nevertheless, the more weak disconfirmations that I found the more my confidence in the theory would be eroded. Although I cannot say what the exact logical entailments between the cosmological and the neurophysiological theory are, it seems to me that tests of the neurophysiological theory can have relevance for the cosmological theory.16
Finally, I would like to mention some implications of the neurophysiological and cosmological theories for a most general problem of philosophy -- the problem of the one and the many. It seems that this problem involves a whole set of problems that cross many disciplines. I want to talk about two of these problems -- the problem of emergent individuality and the problem of relations and relata -- because I believe that this study suggests some productive ways of thinking about them.
The problem of emergent individuality can be put simply: How is it that nature can put together an assortment of things in such a way that it gives rise to an individual who then goes about looking after his interests? This is not just a philosophical problem. It is a problem that holistic approaches to biology such as general systems theory have been most interested in, and it is the problem that prompted C. Lloyd Morgan to speculate about forms of relatedness. The empirical theory that I presented here suggests an experimental approach to this problem. According to the theory, the form of relatedness that characterizes unified, purposive functioning in human beings and lower animals should be manifested in their brain waves -- perhaps in some kind of harmony that appears in the brain wave pattern. Thus, we have an observable variable to study, and we can use the techniques of neuroscience to try to find the essential features of the form of relatedness that underlies emergent individuality. Further, experimental research can potentially reveal the principles of brain organization that make the essential harmony possible in animals, and this might illuminate the general principles underlying all instances of emergent individuality.
The problem of relations and relata is much harder to put into words. It seems like a many-sided problem. I think this study is relevant to its cosmological side -- how do relations and relata make up the world? How are they involved in continua and pluralities, fields and particles, individuals and aggregates? In what sense are these terms complementary -- involved in each other’s meaning?
Again, this study does not answer these questions, but it suggests a promising approach. The kinds of models that I used here can illuminate the roles of relations and relata in the world. The models convert very general ideas into simple images that can be visualized and understood intuitively. For instance, one can take the two complementary phases of the sponge-marble model to represent the complementary roles of relations and relata in the make-up of complex things (see text and note 6). This helps one envision how the holistic properties of a society are a function of the relations among its sub-societies. The interstitium represents the arena for these relations -- physical relations make up the physical fields of the interstitium while physical relata make up the particulate (material) properties of the subsocieties that give rise to the interstitium and its fields. Also the model helps one see how relations and relata make up the hierarchical structure of societies. Each descent to a lower level of a structured society shows relata to be composed of relations among sub-relata. This descent can end only with perfectly simple relata. Alternatively, there may be no elementary relata -- the descent may be endless.
When I began this study I had a vague impression that there is a commonality among the notions of relatedness, emergence, individuality, interstitium, and field. I had a feeling that if I understood this commonality I could make better sense of the relation between conscious experience and the body. It seemed that process cosmology might hold the key, sol tried to put these notions together according to process categories. Although there is still much confusion, I feel that this endeavor has shed light on how mind and body might be related. It has also shown how process cosmology can influence research in neurobehavioral science.
1I overlook several distinctions in the ways physiological psychologists conceive of the mind-brain relation because they are not essential to the point I want to make here. What is relevant here is the common presupposition of scientists that matter (or whatever it is that makes up the physical world) is ontologically prior to experience in the sense that matter can exist without experience but experience cannot exist without matter. In other words experience is the outcome of physiological events because it is a function of the organization of atoms rather than being inherent in the atom itself. Also I want to note that this view is not essential for scientific research. I discuss the advantages of the alternative view of process cosmology elsewhere (George Wolf, "The place of the brain in an ocean of feelings," to be published in a festschrift for Charles Hartshorne edited by John B. Cobb, Jr.).
2Several of the technical terms used in this study do not come from Whitehead’s vocabulary. The terms "individual" and "aggregate" are used by Hartshorne to distinguish societies which are unified by presiding occasions from those which are not. A given society may be an individual at one moment and an aggregate at another moment.
Also, what I call "conscious occasions are what Whitehead calls "final percipient occasions of human experience. I use the term "conscious occasions" for convenience to refer to ordinary human experience, An approximate operational definition is "any moment in the life of a person that he or she can subsequently remember." This definition does not capture everything one usually would call "conscious experience" hut it is adequate for the present purposes.
Finally, this paper is concerned mainly with objective correlates of experience -- what Whitehead called a coordinate analysis of actual occasions. I often use the term superject" (where Whitehead would use the more general designation occasion or "entity") to emphasize that it is the objective features of the occasion that are being discussed. The term ‘conscious superject" can be taken to refer to the physiological correlate of a moment of ordinary human experience, although this does not exhaust its technical meaning.
3There is some controversy about how to interpret the rule that occasions cannot overlap (the problem of "regional inclusion"). For a discussion of this problem see John B. Cobb. Jr., and Donald W. Sherburne, PS 3:27-40 (1973), and earlier papers referred to there. Also, there are several other studies which are relevant to this topic and bring up important problems that I do not deal with here. William Gallagher, PS 4:263-74 (1974), comments on the above discussion, as does Lewis S. Ford, PS 3:104-18 (1973), in a review of a relevant book by Ivor Leclerc, The Nature of Physical Existence (New York; Humanities Press, 1972). Also see F. Bradford Wallack, The Epochal Nature of Process in Whitehead’s Metaphysics (Albany: SUNY Press, 1980).
The notion that one occasion cannot surround another is not explicitly stated in PR, but it is implied in an explanatory paragraph appended to part 4, chapter 2. There Whitehead states, "The inside of a region, its volume, has a complete boundedness denied to the extensive potentiality external to it" (PB 301/ 546). This implies that an actual occasion cannot have the shape of an encasement such as an egg shell, or better, an egg white because the region surrounded by the encasement is external to the region occupied by the encasement itself (as the yolk region is external to the white region), but it has a complete boundedness. If this form is not possible, then complete surrounding is not possible. I do not know how important this notion is in relation to the general scheme of extension that Whitehead had in mind. In any case this restriction does not conflict with the alternative model which I will propose. On the other hand, I found no statements in PR that rule out other complex topological forms for actual occasions, especially perforated forms such as a donut or a lattice, and this is critical to my model.
4C. Lloyd Morgan, Emergent Evolution (London: Williams and Norgate, 1927). Apparently Whitehead was influenced by this work. He mentions it in the preface to, SMW.
5The analogy is imperfect because motile cells such as white blood cells are not connected to other cells and so, according to this model, would be completely surrounded by interstitial stuff. Furthermore, the extracellular fluid compartment is made up of various types of societies -- water molecules, solutes, and cells. The topological relation between a pervasive presiding occasion and these extracellular societies has yet to be worked out. It may be possible to work out a scheme of spatial relations that entirely avoids complete surrounding, but exploring this would take a lengthy analysis. Since the importance of this principle for Whitehead’s theory of extension is not clear to me, I will not pursue this problem further here.
Also, there is no reason to assume that the presiding occasion is the only occasion that pervades the whole interstitium. One can conceive of a variety of types of interstitial occasions (such as varying forms of "entirely living occasions") that might pervade the whole interstitium sort of adjacent to or intertwined with the presiding occasion. Both Sherburne and Gallagher (see references in note 3) feel that a single strand of occasions is not sufficient to account for human experience. They suggest that one should think in terms of a nexus of occasions to account for the variety of preconscious and unconscious elements that color experience. The present model is compatible with this idea.
6There are some additional properties and possible elaborations of the model that are worth mentioning. Note first that the model has two (primary) phases -- a sponge phase and a marbles phase. The two phases are topologically identical and interlocked. To envision this imagine that the marbles are slightly flattened where they touch one another so that the region of contact is spread out rather than being a mere point. Next imagine shaking the marbles out of the sponge, making a cast of the holes, and then peeling off the sponge. The cast of the marbles space has the form of a three dimensional lattice such as a jungle gym -- each marble corresponds to a node where the bars meet. The space between the bars has the same lattice form as the jungle gym. This corresponds to the sponge. Thus, the sponge-marble structure can serve as a sort of geometrical model of the complementarity of continuous and discontinuous aspects of reality -- specifically the complementarity of physical fields (sponge phase) and material objects (marbles phase).
Consider next the relation between adjacent levels of interstitial stuff. In the model that I described in the text, the interstitial stuff around the marbles of the sub-adjacent level is taken to be distinct from (externally connected to) the interstitial stuff inside the marbles. This represents, for example, the difference between the extracellular fluid around body cells and the cytoplasm inside them. But there is also a sense in which the space around body cells is continuous with the space inside them. Electron micrographs show that cell walls fold into the cell to form tortuous invaginated channels into its depths. The space inside these channels is continuous with the space around the cell in the same way that the space inside the alimentary tract is continuous with the space around the body. It is possible to think of this continuity as reaching all the way into the atom -- through the spaces between the proteins that form the cell walls and so on. One would need another version of the sponge-marble model to represent this. In this version the primary interstitial stuff -- or better some feature of the stuff -- sort of worms its way down into successively smaller interstitial spaces. The result is that the hierarchy of sponges and marbles is made tip of a single uniform stuff.
It might be that an adequate model of the spatial features of structured societies would have to combine the features of both versions and maybe more. In any case, I find that models like these can be helpful for thinking about the actual structure of the world. The constraints and the implications of certain relationships become very clear, and the models lend themselves to seemingly endless embellishments that suggest empirical hypotheses.
I consulted with several mathematicians about the properties of the structures which I have described here. They advised me that the relevant topics in geometry are lattices, crystallography and fractals. Many of the interesting properties of the sponge-marble structures depend on their elasticity, and so topology is most relevant here while geometric problems like sphere packing are not.
7To see this unambiguously one must look over the whole range of events from microcosmic to macrocosmic, and one must choose the same type of event at every level. One type of event that occurs ubiquitously is a periodic departure from and return to an origin -- i.e., cycles, pulses, orbits, and so on. Now, the period of an electron is well under a millionth of a second, the human pulse is roughly one per second, and a single rotation of a galaxy takes well over a million years. However, with smaller intervals and different types of events one may encounter significant exceptions to this rule.
Also, it seems more reasonable to think of these periodic events as aggregate events which are the outcome of coordinated activities of constituent occasions than to think of them as acts of single individuals (although Whitehead does identify subatomic pulses with single actual occasions). One might conjecture that such periodic functions of aggregates set the boundary conditions for durations of actual occasions at any given level of a hierarchy.
8It is instructive to spell out the interactions given in the analogy in terms of prehensions. Consider, for example, the prehensive relations between conscious occasions and neural occasions. To simplify this analysis assume that conscious occasions have a uniform duration of 100 milliseconds and neural occasions have a uniform duration of 1 millisecond. Assume further that during a given period of clock time, say a 300 millisecond period, there occur uninterrupted trains of conscious and neural occasions so that there is a passage of a train of 3 generations of conscious occasions and a multitude of trains of 300 generations of neural occasions. One way to envision the prehensive relations between the conscious and neural occasions during this period is as follows. Each conscious occasion prehends the 100 immediately preceding generations of neural occasions as a single nexus. This set of 100 generations of neural occasions forms a distinct nexus because they all directly prehended the same conscious superject, and this constitutes the defining characteristic of the nexus. To put this another way, a conscious superject which comes into being at T100 (milliseconds) functions as an overarching influence upon the concrescences of all neural occasions between T100 and T200. In turn, this nexus of neural occasions provides the main physical data for the conscious occasion that comes into being at T200 and is "present" until T300.
9Paul Weiss, First Considerations (Carbondale: Southern Illinois University Press, 1977). See especially Weiss’s reply to Robert Neville’s criticisms -- pp. 223ff.
10It is not entirely clear how to think about the temporal relation between the genesis of an occasion and its period of superjective presence. Although the genesis does not take place in physical time, it has to be related to physical time in some sense. Thus, it is possible to conceive of the genesis as taking place before the period of superjective presence, at the instant of inception of the period, or concurrently with the period (i.e., the genesis is orthogonal to the arrow of physical time). An adequate discussion of these possibilities would be beyond the scope of this paper, but I want to note that each alternative has serious problems.
11For a discussion of brain wave theories of consciousness see W. Ritter, "Cognition and the brain," in H. Begleiter, ed., Evoked Brain Potentials and Behavior (New York: Plenum Press, 1978), pp. 197-227. This chapter also gives references to other papers on this topic.
12However, there maybe nonconscious, overarching occasions that correspond to the long DC potentials. In note 5 I mentioned the possibility of pervasive interstitial occasions other than the presiding occasion. Such occasions might be very long-lasting and serve to contribute enduring components such as moods and expectancies to our conscious experience. These occasions would contribute to conscious experience only when they were positively prehended by the presiding conscious occasion. One way to get suggestive evidence of such long-lasting occasions is to look for delayed emotional or physiological reactions to stimuli -- reactions which come long after the initial conscious reaction.
13Much of the work that is most relevant to this discussion has been done by W. R. Adey, and he has written several reviews on the subject. Although the work is done in the context of a more general problem -- the effect of environmental electromagnetic fields upon cellular functions -- Adey is also concerned with the question of how brain waves might play a role in normal brain function. See W. R. Adey, "Neurophysiologic effects of radio frequency and microwave radiation," Bulletin of the New York Academy of Medicine 55 (1981), 1079-93.
14Technical details are not too relevant here, but I want to mention briefly that it is unlikely that one would find gross dissociations between the electrical activities in the field and in the neurons because an autonomous change in the field should cause a corresponding change in the neurons. It is more likely that one would find changes in the phase relations between slow waves and intracellular potentials. In other words a conscious voluntary action should be associated with a tendency for the potentials in the field to lead the potentials in the neurons. Furthermore, there is no reason to expect the shifts to be of equal magnitude in all regions of the brain. It is also relevant here that one would have to take into account not only neurons but also, glial cells since these contribute potentials to the electrical field of the brain.
15For a review of this work see E. R. John, "A model of consciousness," in G. E. Schwartz and D. Shapiro, eds., Consciousness and Self-Regulation (New York: Plenum Press, 1976), pp. 1-50.
16But I believe that the relevance of cosmological theories for scientific research does not depend on how readily they can be tested by experiments. Whitehead illuminates the complementarity between speculative and scientific thought in a most general context of evolution and reason in FR. In another paper I give several examples of how process cosmology can benefit science by enhancing the scope of empirical inquiry (see reference in note 1).