Saturday, September 6, 2014
The Human Brain by Isaac Asimov
Well, long story short, it wasn’t. At least not directly in any way I could find. The use of language seems to assume a decidedly dualist perspective, such as…
These two sets of visceral fibers, the preganglionic and the postganglionic, taken together with the ganglia themselves, make up that portion of the nervous system which is autonomous--or, not under the control of the will.
The will. Assumed to exist, but not explained. And…
To be aware of the environment, one must sense or perceive it.
One. Assuming there is an entity there to do the sensing. Maybe you think I’m nitpicking, but given all the dissecting of brain tissue and chemical substances that Asimov devotes most of the book to, isn’t it noteworthy to say no markings of consciousness are to be found in anything but the author’s assumptions?
Indeed, there are times when Asimov is quite transparent with the limitations of his then understanding of how the brain functions. In a long, opening section devoted to glands and their secretions, he says:
Yet what is it that thyroxine, tri-iodothyronine, and possible related compounds do to bring about such changes? What particular reaction or reactions do they stimulate in order to lift the entire level of metabolism? And how does iodine play a role? This is perhaps the most fascinating aspect of the problem, because no compound without iodine has any thyroid hormone activity whatever. Furthermore, there is no iodine in any compound present in our body except for the various forms of the thyroid hormone.
By now you should not be surprised at learning that there is no answer as yet to these questions.
I don’t know if medical science has been able to answer Asimov’s questions since he posed them in 1963, but it does show that he is willing to chase the knowledge of what the brain is and how it functions to the very limit of his understanding.
But not, evidently, when it comes to thinking philosophically about the self.
Asimov actually becomes somewhat moralizing near the end of the book, where he begins to compare to brain of the human to other brains in the animal kingdom.
Man strikes a happy medium, then. Any creature with a brain much larger than man’s has a body so huge that intelligence comparable to ours is impossible. Contrarily, any creature with a brain/body ratio much larger than ours has a brain so small in absolute size that intelligence comparable to ours is impossible.
Bold and striking statements, but dear Isaac--how can you possibly know these things? On what yardstick does one measure intelligence? Brain/body ratios? Size of the prefrontal cortex? Both have been examined and found wanting--but both remain seemingly common sense explanations for the apparent uniqueness of human intelligence.
Moreover, from Asimov’s perspective we can look at other natural phenomena and proclaim an enlightened understanding that no intelligence or will is actually there.
Because this alliance of purpose and response is so well known to us, we tend to read purpose into the action of other creatures that cannot possibly have modes of thought akin to ours. For example, in observing that a green plant will turn toward the light, and knowing that light is essential to the plant’s metabolism (so that receiving light contributes to its “well-being”), we are tempted to conclude that the plant turns to the light because it wants to, or because it likes the sensation, or because it is “hungry.” Actually this is not at all so. The plant (as nearly as we can tell) has no awareness of its action in any sense that can be considered even remotely human. Its action is developed through the same blind and slow evolutionary forces that molded its structure.
Yet, he seems reluctant to consider the processes from which the reactions of the plant grew almost certainly contain the genesis of our own. I say we are different in degree, not in kind, but Asimov seems intent on preserving the sharpest of distinctions between humans and the rest of the animal kingdom. His longest argument comes near the very end, when he tackles what he calls the “behaviorist stand.”
Even granted that the behaviorist stand is correct in principle and that all human behavior, however complex, can be brought down to a mechanical pattern of nerve cells (and hormones)* the further question arises as to whether it is useful to allow matters to rest there.
The asterisk leads one to the following footnote:
*Actually, it is difficult to deny this since nerves and hormones are the only physical-chemical mediators for behavior that we know of. Unless we postulate the existence of something beyond the physical-chemical (something like abstract “mind” or “soul”) we are reduced to finding the answer to even the highest human abilities somewhere among the cells of the nervous system or among the chemicals in the blood--exactly where we find the lowest.
I want to tackle this head-on. Why down? Why is explaining human behavior and action through natural, observable phenomena taking things down? Down from what? From something that exists only in our imagination? Do we talk about modern chemistry as reducing things down from the heights of the theory of the four elements--earth, air, fire and water? Using science to explain human behavior is not bringing anything down. It provides an explanation that is more complex that any based on the existence of the abstract “mind” or “soul.” It is not down. It is up.
But back to Asimov. I’m going to quote him at length, because I want to preserve as much as his argument as possible. In tackling the difference in kind that he believes humans possess, he makes the following analogy to material phase changes.
Briefly, as a change progresses there can come a point (sometimes quite a sharp one) where the outlook must change, where a difference in degree suddenly becomes the equivalent of a difference in kind. To take an analogy in the world of the physical sciences, let us consider ice. Its structure is pretty well understood on the molecular level. If ice is heated, the molecules vibrate more and more until at a certain temperature, the vibrations are energetic enough to overcome the intermolecular attractions. The molecules then lose their order and become randomly distributed; in a fashion, moreover, that changes randomly with time. There has been a “phase change”; the ice has melted and become water. The molecules in liquid water are like the molecules in ice and it is possible to work out a set of rules that will hold for the behavior of those molecules in both ice and water. The phase changes is so sharp, however, as to make it more useful to describe ice and water in different terms, to think of water in connections with other liquids and ice in connection with other solids.
I think this analogy is fatally flawed. There is no phase change in evolution, no place where you can zoom in and see one thing and one side and another thing on the other--except, perhaps, at the level of gene mutations. The reason we seem so different is because the other hominid species went extinct and the closest relatives we have left with are the chimps and bonobos. But what would the world look like if there were dozens of additional living species on our family tree, each exhibiting traits of intelligence and consciousness on a continuum with humans on one end and chimps on the other? Would we be so distinct then? Where would Asimov put his phase change then?
Eventually, Asimov, will almost concede this point, but let’s allow him to continue, using his analogy to explain the difference between man and the rest of the animal kingdom.
The concept of the phase change can also be used to answer the question of what fixes the gulf between man and all other creatures. Since it is not reason alone, it must be something more. A phase change must take place not at the moment when reason is introduced but at some time when reason passes a certain point of intensity. The point is, one might reasonably suppose, that at which reason becomes complex enough to allow abstraction; when it allows the establishment of symbols to stand for concepts, which in turn stand for collections of things or actions or qualities. The sound “table” represents not merely this table and that table, but a concept of “all table-like objects,” a concept that does not exist physically. The sound “table” is this an abstraction of an abstraction.
Once it is possible to conceive an abstraction and represent it by a sound, communication becomes possible at a level of complexity and meaningfulness far beyond that possible otherwise. As the motor areas of the brain develop to the point where a speech center exists, enough different sounds can be made, easily and surely, to supply each of a vast number of concepts with individual sounds. And there is enough room for memory units in a brain of such complexity to keep all the necessary associations of sound and concept firmly in mind.
It is speech, then, rather than reason alone that is the phase change, and that fixes the gulf between man and nonman. As I pointed out on page 246, the existence of speech means that the gathering of experience and the drawing of conclusions is no longer a function of the individual alone. Experience is shared and the tribe becomes wiser and more knowledgeable than any individual in it. Moreover, experience unites the tribe throughout time as well as throughout space. Each generation need no longer start from scratch, as must all other creatures. Human parents can pass on their experiences and wisdom to their children, not only by demonstration but by verbalized, conceptual explanation. Not only facts and techniques, but also thought and deduction can be passed on.
Perhaps the gulf between ourselves and the rest of living species might not seem so broad if we knew more about the various prehuman hominids, who might represent stages within that gap. Unfortunately we don’t. We do not actually know at what stage of development or in what species of hominid, the phase change took place.*
There it is. The glimmer of his own undoing when he speculates on the hominids. But he’s still clearly hanging his hat on the idea of the phase change--that something didn’t exist in one generation and suddenly it did in the next. It might be correct when discussing how ice turns into water, but it isn’t when discussing how species evolve. Because that’s where evolution happens. Not to individuals but to species, and the only way to think of change is to think of it as part of a never ending continuum. Will, intelligence, consciousness--they are no different from thousands of biological and anatomical attributes in the sense that all living creatures have them in some degree--some so little that they are not even recognizable to us as those factors--but all in some degree.
But note how Asimov ended that paragraph with another asterisk. Here’s where that one leads:
*If it is true that dolphins have a faculty of speech as complex as that of man, then we are not necessarily the only species to have passed the phase change. The environment of the ocean is so different from that of land, however, that the consequences of the phase change would be vastly different. A dolphin might have a man-level mind, but in the viscous and light-absorbing medium of sea water a dolphin is condemned to the flipper and to a dependence on sound rather than vision. Man is not man by mind alone, but by mind plus eye plus hand, and if all three are taken into consideration we remain the only species this side of the phase change.
I find Asimov’s use of the word “condemned” to be very revealing. The dolphin may have a man-level mind, but it is still nothing like us because it doesn't have the things that we value or to which we owe our development. In other words, let’s first create a category--which is completely arbitrary but to which only man can belong--and then use that category to assert and reassure ourselves that we are unique and superior to everything else that doesn't fit into that category. And who created that category again? By the same logic, a dolphin could create a category for big-brained animals that swim in the ocean and breathe through holes on the top of their heads, call that their phase change, and exclude the rest of creation from their elite club.
Because here’s the essential question. What creates consciousness? Asimov doesn't know. He found it nowhere in his detailed dissection of the human brain. He conjectures that it comes from the things that are uniquely human, but he doesn't know this, and nor do we know it today. To the best of our understanding, consciousness is an emergent property of life, and by that definition, every living thing has it in some measure. There is no phase change. Just a long, unbroken continuum of stimulus response and cognitive awareness. They are not, apparently, different things, but ends of the same spectrum.
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This post was written by Eric Lanke, an association executive, blogger and author. For more information, visit www.ericlanke.blogspot.com, follow him on Twitter @ericlanke or contact him at email@example.com.