Caution in science Caution in science Hypotheses- role in science Indirect perception, representationalism Indirect perception, representationalism Isomorphism Isomorphism Local recording, single-cell electrode Resonance in the brain
Why are the objects of the phenomenal world perceived as before us, outside of ourselves, even though today everybody knows that they depend upon processes inside of us, in the central nervous system? ... Many of the greatest physiologists, among them even Helmholtz, have failed to achieve full clarity on this question. Mach and Avenarius attempted to lead the scientific world away from the errors already implicit in the formulation of the paradox. But either their explanations remain little known, or they did not sufficiently elucidate the problem. For only a few years ago a well-known physician raised the question anew: "How is it that consciousness, which is bound to an organism, relates the changes in its sense organs to something located outside of itself?" All attempts to explain this "compulsion to project" appeared useless to him, for he felt that here is one of the eternal enigmas, related to the mind-body problem. It seems clear that this contemporary physician is not alone; rather he represents the majority of natural scientists.
The physical processes between object and sense organ are followed by further events which are propagated through nerves and nerve cells as far as certain regions of the brain. Somewhere in these regions processes take place which are tied to the occurrence of perception ... Now it would obviously be meaningless to identify with each other the starting point and such a late or distant phase of this sequence of events ... If I shoot at a target, nobody will claim that the hole in the target is the same thing as the revolver from which the bullet came.
We might be tempted to say that parts of the phenomenal world should not be thought of as localized in any place in the physical world as a matter of principle, since phenomenal and physical localizations are incommensurable. ... Let us assume that ... the total phenomenal world of a person is simply not definitely localizable anywhere in the physical world ... Then it follows that we may arbitrarily think of [it] wherever in the physical world it would help our thinking. ... Now, according to our basic assumption, the totality of a person's perceptual world is strictly correlated with certain processes in his central nervous system. It will then simplify our discussion and our terminology if, in what follows, we ... think of [it] as being mapped on those brain processes which certainly at least correspond to them.
I do not believe that ... I need defend the strict distinction between percepts and physical objects any further. But why is it so difficult to convince people that this distinction is necessary? [Perhaps because they] may not yet have been able to discard the last remnants of naive realism from their philosophy of science. I admit that this is a hard task for all of us.
It is actually simpler to find authors who commit this error than people who have recognized it as an error. The mistake was first corrected a hundred years ago, in 1862, by Ewald Hering - an extrordinary achievement ... characteristically enough, in his publication Hering made a pessimistic remark about the chances that his explanation would be understood by his contemporaries. As a matter of fact, few ever became acquainted with it during the past hundred years, and not very many seem to know about it now.
What we call the self is just one more directly accessible percept ... . When dealing with perception more in detail we shall find it necessary to distinguish sharply between the self as a percept and the physical organism in question.
Do we really see physical objects? I like to answer questions of this kind because only when they are answered wil the conceptual confusions ... finally disappear. When we consider the long chain of events that connects physical facts in our physical environment with directly accessible percepts, our answer to this particular question can only be a clear NO.
Originally published as...
...Bremer's excellent experiments. Under the influence of strychnine, the motor neurons in the spinal chord of the curarized cat get into a state of rythmic excitation. The frequency of the waves varies from about ten to thirty per second. What is remarkable, however, is that, from one end of the spinal chord to the other, the electrical waves are exactly in phase, i.e. synchronized. This can naturally be explained only by a mutual influence of the greatest speed, a speed never achieved by the propagation of excitation in fibers and through synapses. Bremer himself speaks, therefore, of an electrical interaction of the active cells. That this is really what happens he then demonstrated convincingly in a separate experiment. He completely severed the spinal chord in one place, so that between its two parts no histological connection existed, but only physical contact. When he then picked up the rythm simultaneously from two places on either side of the cut, the synchronization of the waves on the two sides was not in the least disturbed. Since Gerard and Libet have also demonstrated similar phenomena in the frogs brain, there is no longer any doubt: active elements of the nervous system are surrounded by electric fields or currents which spread in the tissue as a continuous conductor...
The old belief in the primary importance of purely local facts is still very much alive. In fact, it is now strengthened by the invention of new devices, the micro-electrodes, which permit the psychologist to take records from individual cells in the nervous system. One cannot object to the use of such tools. Some questions concerning the elements of the nervous system are now being answered with their help. But they contribute little to our knowledge of molar, macroscopic brain processes, which is far more important for our understanding of psychological facts.
what physiological events occur in [the cortex] when human beings have perceptual experiences ...?
Wilhelm Wundt ... gave this radical answer: "Brain processes and corresponding psychophysical facts differ entirely as to the nature of both their elements and of the connections among these elements".
Why should ... a similarity of behavior of perceptual and physical facts become impossible when the physical facts in question happen to physiological processes in the brain? ... To be sure, human perception contains many facts the like of which never occur in the physical world. Take the sensory qualities of vision, such as blue, gray, yellow, green, and red. In the physical world, the physicists find nothing that resembles these qualities, and nobody expects physiological processes in the visual cortex of the brain to have such characteristics. But we did not refer to sensory qualities when we began to suspect tht certain properties of perceptual fields resemble properties of cortical processes to which they are related. The properties we had in mind were structural properties. For instance, under certain conditions, perceptual processes tend to assume regular and simple forms, and we suspect that under the same conditions, corresponding processes in the brain show the same tendency, then we refer to what I just called "structural" characteristics. It is only such structural characteristics which, not only in this case but in many others, perceptual facts and corresponding brain events may have in common. In 1920 the Gestalt psychologists transformed this assumption into the following general hypothesis. Psychological facts and the underlying events in the brain resemble each other in all their structural characteristics. Today, we call this the hypothesis of Psychophysical Isomorphism.
...a further remark about what I called "structure" of physical events seems indicated. Sometimes the term "structure" is used in a purely geometrical sense. But when I use the term in our present connection, it refers to a functional aspect of processes, to the distribution of such processes, a distribution which they assume ... as a consequence of the dynamic interrelations or interactions among their parts.
[Why are great discoveries not being made in psychology equivalent to discoveries in physics, such as x-rays, radioactivity, quantum effects?]
The reason is not that such discoveries are more difficult in psychology than they are in physics; ... rather ... because man was acquainted with practically all territories of mental life a long time before the founding of scientific psychology. In other words psychologists could not make such startling discoveries as constitute the pride of physics, because at the very beginning of their work there were no entirely unknown mental facts left which they could have discovered.
[drives, habit, memory, moods, emotions, thinking, attention, sleep, dreams]
Why should we assume that any such facts are left? It seems quite possible that no discoveries in this sense will occur even in the future of our science.
I doubt whether it is advisable to regard caution and a critical spirit as the virtues of a scientist, as though little else counted. They are necessary in research, just as the brakes in our cars must be kept in order and their windshields clean. But it is not because of the brakes or of the windshields that we drive. Similarly, caution and a critical spirit are like tools. They ought to be kept ready during a scientific enterprise; however the main business of science is gaining more and more new knowledge. ... Why are just psychologists so inclined to greet the announcement of a new fact (or a new working hypothesis) almost with scorn? This is caution that has gone sour and has almost become negativism. ... Too many young psycholotists ... either work only against something done by others, or merely vary slightly what others have done before; in other words, preoccupation with method may tend to limit the range of our research.
Our wish to use only perfect methods and clear concepts has led to methodological behaviorism. Human experience in the phenomenological sense cannot yet be treated with our most reliable methods; and when dealing with it, we may be forced to form new concepts which at first, will often be a bit vague. Most experimentalists, therefore, refrain from observing, or even from referring to, the phenomenal scene. And yet, this is the scene on which, so far as the actors are concerned, the drama of ordinary human living is being played all the time. If we never study this scene, but insist onmethods and concepts developed in research "from the outside", our results are likely to look strange to those who intensely live "inside".
In new fields, not only quantitative data are relevant.
"Natural sciences continually advance explanatory hypotheses, which cannot be verified by direct observation at the time when they are formed nor for a long time thereafter. Of such a kind were Ampere's theory of magnetism, the kinetic theory of gases, the electronic theory, the hypothesis of atomic disintegration in the theory of radioactivity. Some of these assumptions have since been verified by direct observation, or have at least come close to such direct verification; others re still far removed from it. But physics and chemistry would have been condemned to a permanent embryonic state had they abstained from such hypotheses; their development seems rather like a continuous effort steadily to shorten the rest of the way to the verification of hypotheses which survive this process"
"Any actual consciousness is in every case not only blindly coupled to its corresponding physiological processes, but is akin to it in essential structural properties"
Thus, isomorphism, a term implying equality of form, makes the bold assumption that the "motion of the atoms and molecules of the brain" are not "fundamentally different from thoughts and feelings" but in their molar aspectes, considered as processes in extension, identical.
It is quite true that, in natural science, all observation of systems is observation "from the outside." But does it follow that, when the psychologist deals with human subjects, he must always use the same procedure? Must he also restrict his observations to behavior as watched from the outside? Why should he not be interested in mental life as experienced by himself or others? If a certain scientific enterprise which we admire has unfortunately only one kind of access to its material, why should psychology, which has two, refuse to make use of both?
In [the] methodological sense, most American psychologists now seem to be behaviorists. Under the circumstances, not only details but also most impressive aspects of the phenomenal scene are often ignored in the psychologist's work. Their admiration of method, of precision, prevents them from paying attention to phenomenological evidence even when this evidence could hardly escape the very simplest observation. Naturally, the psychologists' sin of omission makes them incapable of contributing to the solution of the mind-body problem in its most serious form, in which it refers to the relation between the phenomenal scene and the characteristics of events in nature. Once more, one cannot study the relation between two groups of facts without knowing the facts in each group per se.