The Meaning of Human Existence (14 page)

The procedure of the more skeptical philosophers is top-down and introspective—thinking about how we think, then adducing explanations, or else discovering reasons why there can be no explanation. They describe the phenomena and they provide thought-provoking examples. They conclude that there is something fundamentally
different from ordinary reality in the conscious mind. Whatever that may be, it is better left to philosophers and poets.

Neuroscientists, who are relentlessly bottom-up as opposed to top-down, will have none of this. They have no illusions about the difficulty of the task, understanding that mountains are not provided with escalators built for dreamers. They agree with Darwin that the mind is a citadel that cannot be taken by frontal assault. They have set out instead to break through to its inner recesses with multiple probes along the ramparts, opening breaches here and there, and by technical ingenuity and force enter and explore wherever space is found to maneuver.

You have to have faith to be a neuroscientist. Who knows where consciousness and free will may be hidden—assuming they even exist as integral processes and entities? Will they emerge in time, metamorphosing from the data like a butterfly from a caterpillar, the image filling us like Keats’s men around Balboa with a wild surmise? Meanwhile, neuroscience, primarily because of its relevance to medicine, has grown rich. Its research projects are growing on budgets of hundreds of millions to billions each year. (In the science trade it’s called Big Science.) The same surge has occurred, successfully, in cancer research, the space shuttle, and experimental particle physics.

As I write, neuroscientists have begun the direct assault Darwin called impossible. It envisions an effort called the Brain Activity Map (BAM) Project, conceived by key government institutes in the United States, including the National Institutes of Health and National Science Foundation, in collaboration with the Allen Institute for Brain Science, and endorsed as government policy by President Obama. The program, if successfully funded, will parallel in magnitude the Human Genome Project, which was the biology moon shot completed in 2003. Its goal is nothing less than a map of the activity of every neuron in real time. Much of the technology will have to be developed on the job.

The basic goal of activity mapping is to connect all of the processes of thought—rational and emotional, conscious, preconscious, and unconscious, held both still and moving through time—to a physical base. It won’t come easy. Bite into a lemon, fall into bed, recall a departed friend, watch the sun sink beyond the western sea. Each episode comprises mass neuronal activity so elaborate, so little of which as yet been seen, we cannot even conceive it, much less write it down as a repertory of firing cells.

Skepticism concerning BAM is rife among scientists, but that is nothing new. The same resistance was also the case for the Human Genome Project and much of space exploration being conducted by NASA. An added
incentive to push ahead is the practical application mapping will have for medicine—in particular the cellular and molecular foundations of mental illness and the discovery of deleterious mutations even before the symptoms are expressed.

Assuming that BAM or other, similar enterprises are successful, how might they solve the riddle of consciousness and free will? I suggest that the solution will come relatively early in the functional mapping program rather than as a grand finale at the end, and providing neurobiology remains favored as Big Science. In evidence is the large amount of information already archived in brain studies, and especially as it is combined with the principles of evolutionary biology.

There are several reasons for optimism in the search for an early solution. First is the gradual emergence of consciousness during evolution. The extraordinarily high human level was not reached suddenly, like a light turned on with the flick of a switch. The gradual albeit rapid increase in brain size leading up from the habiline prehumans to
Homo sapiens
suggests that consciousness evolved in steps, in a manner similar to those of other complex biological systems—the eukaryotic cell, for example, or the animal eye, or colonial life in insects.

It should then be possible to track the steps leading to human consciousness through studies of animal species
that have come partway to the human level. The mouse has been a prominent model in early brain-mapping research, and will continue to be productive. This species has considerable technical advantages, including convenient laboratory rearing (for a mammal) and a strong supporting foundation of prior genetic and neuroscience research. A closer approach to the actual sequence can be made, however, by also adding humanity’s closest phylogenetic relatives among the Old World primates, from lemurs and galagos at the more primitive end to rhesus macaques and chimpanzees at the higher end. The comparison would reveal what neural circuits and activities were attained by nonhuman species, and when and in what sequence. The data obtained might detect, even at a relatively early stage of research, the neurobiological traits that are uniquely human.

The second point of entry into the realm of consciousness and free will is the identification of emergent phenomena—entities and processes that come into existence only with the joining of preexisting entities and processes. They will be found, if the results of current research are indicative, in the linkage and synchronized activity of various parts of both the sensory system and the brain.

Meanwhile, the nervous system can be usefully conceived as a superbly well organized superorganism built
upon a division of labor and specialization in the society of cells—around which the body plays a primarily supportive role. An analog, if you will, is to be found in a queen ant or termite, and her supporting swarm of workers. Each worker on its own is relatively stupid. It follows a program of blind, untutored instinct, which is subject to only a small amount of flexibility in its expression. The program directs the worker to specialize on one or two tasks at a time, and to change programs in a particular sequence—typically nurse to builder and guard to forager—as the worker ages. All the workers together are in contrast brilliant. They address all needed tasks simultaneously, and can shift the weight of their effort to meet potentially lethal emergencies such as flooding, starvation, and attacks by enemy colonies. This comparison should not be considered a stretch. Something like it has been a common theme in serious literature as far back as Douglas Hofstadter’s 1979 classic
Gödel, Escher, Bach: An Eternal Golden Braid
.

A strong additional advantage is the narrowness of the range of human perception. Our sight, hearing, and other senses impart the feeling that we are aware of almost everything around us in both space and time. Yet, as I’ve emphasized earlier, we are aware of only minute slivers of space-time, and even less of the energy fields, in which we exist. The conscious mind is a map
of our awareness in the intersection only of those parts of the continua we happen to occupy. It allows us to see and know those events that most affect our survival in the real world, or, more precisely, the real world in which our prehuman ancestry evolved. To understand sensory information and the passage of time is to understand a large part of consciousness itself. Advance in this direction might prove easier than previously assumed.

The final reason I’d like to suggest for optimism is the human necessity for confabulation. Our minds consist of storytelling. In each instant of present time, a flood of real-world information flows into our senses. Added to the severe limitation of the senses is the fact that the information they receive far exceeds what the brain can process. To augment this fraction, we summon the stories of past events for context and meaning. We compare them with the unfolding past to apply the decisions that were made back in time, variously right or wrong. Then we look forward to create—not just to recall this time—multiple competing scenarios. These are weighed against one another by the suppressing or intensifying effect imposed by aroused emotional centers. A choice is made in the unconscious centers of the brain, it turns out from recent studies, several seconds before the decision arrives in the conscious part.

Conscious mental life is built entirely from confabulation.
It is a constant review of stories experienced in the past and competing stories invented for the future. By necessity most conform to the present real world as best it can be processed by our rather paltry senses. Memories of past episodes are repeated for pleasure, for rehearsal, for planning, or for various combinations of the three. Some of the memories are altered into abstractions and metaphors, the higher generic units that increase the speed and effectiveness of the conscious process.

Most conscious activity contains elements of social interactions. We are fascinated by the histories and emotional responses of others. We play games, both imaginary and real, based on the reading of intention and probable response. Sophisticated stories at this level require a big brain housing vast memory banks. In the human world that capacity evolved long ago as an aid to survival.

If consciousness has a material basis, can the same be true for free will? Put another way, what if anything in the manifold activities of the brain could possibly pull away from the brain’s machinery in order to create scenarios and make decisions of its own? The answer is of course the self. And what would that be? And where is it? The self cannot exist as a paranormal being living on its own within the brain. It is instead the central dramatic character of the confabulated scenarios. In these
stories it is always on center stage, if not as participant then as observer and commentator, because that is where all of the sensory information arrives and is integrated. The stories that compose the conscious mind cannot be taken away from the mind’s physical neurobiological system, which serves as script writer, director, and cast combined. The self, despite the illusion of its independence created in the scenarios, is part of the anatomy and physiology of the body.

The power to explain consciousness will, however, always be limited. Suppose that the neuroscientists somehow successfully learned all of the processes of the brain of a single person in detail. Could they then explain the mind of that particular individual? No, not even close. It would require opening up the immense store of the brain’s particular memories, both those images and events available to immediate recall and others buried deep in the unconscious. And if such a feat were possible, even in a limited way, its accomplishment would modify the memories and the emotional centers that respond to the memories, causing a new mind to emerge.

Then there is the element of chance. The body and brain comprise legions of communicating cells, which shift in discordant patterns that cannot even be imagined by the conscious minds they compose. The cells are bombarded every instant by outside stimuli unpredictable
by human intelligence. Any one of these events can entrain a cascade of changes in local neural patterns, and scenarios of individual minds changed by them are all but infinite in detail. The content is dynamic, changing instant by instant in accordance with the unique history and physiology of the individual.

Because the individual mind cannot be fully described by itself or by any separate researcher, the self—celebrated star player in the scenarios of consciousness—can go on passionately believing in its independence and free will. And that is a very fortunate Darwinian circumstance. Confidence in free will is biologically adaptive. Without it the conscious mind, at best a fragile dark window on the real world, would be cursed by fatalism. Like a prisoner confined for life to solitary confinement, deprived of any freedom to explore and starving for surprise, it would deteriorate.

So, does free will exist? Yes, if not in ultimate reality, then at least in the operational sense necessary for sanity and thereby for the perpetuation of the human species.

V

A HUMAN FUTURE

I
N THE TECHNOSCIENTIFIC AGE, FREEDOM HAS

ACQUIRED A NEW MEANING.
L
IKE AN ADULT

EMERGING FROM CHILDHOOD, WE HAVE A

VASTLY WIDER RANGE OF CHOICES BUT ALSO A

COMPARABLY LARGER NUMBER OF RISKS AND

RESPONSIBILITIES.

15

Alone and Free in the Universe

W
hat does the story of our species tell us? By this I mean the narrative made visible by science, not the archaic version soaked in religion and ideology. I believe the evidence is massive enough and clear enough to tell us this much: We were created not by a supernatural intelligence but by chance and necessity as one species out of millions of species in Earth’s biosphere. Hope and wish for otherwise as we will, there is no evidence of an external grace shining down upon us, no demonstrable destiny or purpose assigned us, no second life vouchsafed us for the end of the present one. We are, it seems, completely alone. And that in my opinion is a very good thing. It means we are completely free. As a result we can more easily diagnose the etiology of the irrational beliefs that so unjustifiably divide us. Laid before us are new options scarcely dreamed of in earlier ages. They
empower us to address with more confidence the greatest goal of all time, the unity of the human race.