| SOUL SEARCH (what is this?) A Scientist Explores the Afterlife David Darling 
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Unless you know what it is, I ain't never going to be able to explain it to you.
– Louis Armstrong, on jazz
We have an overwhelming sense of self, of being a particular, permanent focus of being. Our experience is powerfully "I"-centered. We assume we know implicitly what this "I" is and, therefore, that questions such as "Will I survive death?" are meaningful and must have a definite (if as yet unknown) answer.
We think of the "I" within us as being central and transcendent, as Descartes did, because this is just the way it feels. A single, inner voice seems to shape our thoughts, to make choices and pass judgments. It convinces us that we exist as individuals. It is us, our personalized selves, the free-floating observer in the brain. And yet it may also be a most extraordinary illusion.
"I think, therefore I am," declared Descartes. However, recent dramatic experimental results, such as those achieved by Benjamin Libet, a physiologist at the University of California at Los Angeles, challenge the notion that there is Cartesian observer, a localized "I" inside our heads, watching and controlling everything we do.
Over the past decade or so, Libet has been steadily amassing evidence that suggests it may take up to half a second for our conscious impressions of the world to form. The feeling we have of living in the present, in fact, may be just a clever trick, and we can only really know about events, even those over which we were sure we had exercised conscious control, after they have already happened.
One of Libet's experiments involved connecting subjects to an EEG and asking them to flex their wrist spontaneously at any moment they felt the urge. He found that the subjects showed a readiness potential – a sharp drop in electrical activity in the brain that serves to clear the way for a neural event – a full half-second before any wrist flexions occurred. Even more surprising, this readiness potential showed up a good three hundred milliseconds before subjects reported consciously experiencing any impulse to make a move.
In a second test, a light touch on the hand of the subject was followed by a second stimulus, an electrical impulse, direct to the part of the brain that maps sensations for touch. Libet found that if the direct impulse followed four hundred milliseconds after the touch, the two stimuli merged and were experienced as a single, heightened response. Crucially, not only was the lapse in time between the two events not noticed, but the combined event felt as if it had happened a half-second earlier. From the subject's point of view, the experience was timed to the moment the hand was touched rather than to when the brain was directly stimulated.
Libet sums up these astonishing results like this: "The brain seems to be able to compensate for the lag in its processing. It can refer everything that happened backward in time to the moment it [the stimulus] first arrived at the brain so that, subjectively, it feels as if we are living in the immediate present."
Evidently, brain events take an unexpectedly long time to bubble up and form a coherent picture. Much of our thinking, reacting, and decision-making takes place at a subconscious level, with consciousness only seeming to do all the work and only seeming to act in concert with stimuli and response.
Libet's work ties in well with the experience of athletes whose sports demand accurate split-second decisions. Tennis players frequently talk of being "zoned," when their minds attain a Zenlike wordlessness and their shots flow with fluid grace. What they appear to be doing in this state is blocking the distracting chatter of conscious thought, putting consciousness in the backseat and allowing their brains to be given over to subconscious processing.
Support for this idea comes from an experiment by University of California at Berkeley psychologist Arthur Jensen. He asked a group of volunteers to deliberately delay their responses in a reaction-time test by as short an interval as possible. Their reaction times were found to increase not marginally but by a big jump – from 250 milliseconds to 600 or 700 milliseconds. Apparently, the need to wait for consciousness to make a decision is what causes this disjointed delay, a result which suggests that allowing consciousness to take control of a skilled action such as a tennis return will lead to a clumsy, jerky response. Science, it seems, has found the answer to another of those great sporting mysteries – why even a grand-slam pro is apt to swat a tempting lob wildly out of court or drill it into the bottom of the net. With the ball hanging in the air for so long, consciousness has time to catch up with events and then, like an overzealous novice, rushes in and makes a complete hash of what otherwise would have been the easiest of winners.
On a more profound level, Libet’s results expose the fatal flaw in Descartes' Cogito... – that is, the belief that there is a pontifical "I" holding court at some specific site within the brain. Neurologist Daniel Dennett, head of the Center for Cognitive Studies at Tufts University, has attacked this notion as "the most tenacious bad idea bedeviling our attempts to think about consciousness." Research such as Libet's shows there is no precise instant when the brain becomes aware of a stimulus. This failure, Dennett claims, demolishes the long-held concept of the Cartesian "I" inhabiting the brain.
How can there be a privileged ghost or homunculus watching from inside the brain-machine if it cannot time when it "knows" about an event so that it can decide to tell the brain what to do or say in response? New research on speech production also casts doubt on the theory that posits a central "meaner" who decides what "I" think and then orders the mouth to utter the desired words. The novelist E. M. Forster was there first when he sniped: "How do I know what I think till I see what I say?"
Dennett advocates connectionism as a key to further progress. Connectionism argues that the brain is an enormously complex parallel processing machine. At any moment, many neural networks are simultaneously at work handling incoming information. Different networks take precedence at different times as alarm bells ring. Effectively, it is as if hordes of homunculi were clamoring and competing for attention, each specializing in a different aspect of perception. As they go about their tasks, they confer with one another and form coalitions, producing drafts of the raw data they take in. The process goes on ceaselessly: information entering the nervous system is under continuous editorial revision, so that at any point in time there are multiple drafts of narrative fragments at various stages of editing scattered about the brain. Ultimately, Dennett says, "we" experience this as a single narrative – a coherent, unified stream of consciousness – in the same way that our eyes seem to bring us a clear, steady image of the world although they jiggle around like handheld cameras.
Self may be a sleight of the brain. But that doesn't make it any less important from a subjective viewpoint. A chair reduces to a near-empty cloud of particles at the subatomic level but is evidently still solid enough to sit on. Who is to say when one thing is more real than another? The "I" inside each of us exists in the sense that we undeniably feel like individuals, distinct and different from all others. Perhaps Descartes should be paraphrased: "I think as if I am, therefore I am!"
When we ask whether there is life after death, we usually mean "Does the ego, the 'real me,' continue in some form?" In other words, can the experience of self-consciousness persist after the brain stops working – after it literally "gives up the ghost"? This, points out the mathematician and philosopher Martin Gardner, is the crux of the debate as far as most people are concerned. "Personal immortality," he has written, "has nothing to do with living on through descendants and friends, or living in future records of the past. It has nothing to do with surviving through achievements in science, literature, music, or art... A person does not acquire immortality by identifying himself or herself with the human race, even if one makes the dubious assumption that the race will never become extinct." Immortality, Gardner insists, requires on-going consciousness of personal identity and personal memories.
One of the hallmarks of consciousness is that it seems so strongly localized in the individual. "I" go to sleep in my forty-year-old body in the north of England, surrounded by familiar people and things, and wake up feeling, as always, like "me," in more or less the same state. I never find myself in the brain of an Amazonian tribesman or an Icelandic barmaid, seeing the world from a totally different perspective. I never look out through unfamiliar eyes, or (consciously at least) share another's thoughts. I seem to be firmly stuck inside this particular body and brain.
But what of identical twins? From an early age, we grasp the meaning of identity and diversity in the world outside and in our own persons. We come to recognize our uniqueness as individuals. Yet in the case of identical twins, identity and diversity coincide. Could it be that such persons, in a sense, experience a single overlapping consciousness rather than two entirely separate selves?
Identical twins display a fascinating mirror symmetry. If one twin has a birthmark on the right cheek, the other often bears it on the left; if one's right eye is slightly darker than the left, the opposite is true for his co-twin; right-handedness in one implies left-handedness in the other. Yet the parallels seem to extend far beyond mere physical equivalence, with occasionally remarkable results.
On March 11, 1979, the Chicago Tribune reported on the reunion of twins who, having been adopted at birth, had been brought up separately and had lived apart for thirty-nine years. In spite of not having seen each other in all that time, each had married a woman named Linda and then divorced; each named a son James Allen; each then married a woman named Betty. Their hobbies – mechanical lettering and carpentry – were the same; their favorite resort was the same beach in the St. Petersburg area of Florida; their occupations were similar.
When we look at other people, we see beings who are obviously like us in some ways and who on many occasions, reason insists, must have similar thoughts. An identical twin, however, sees not just similarity but sameness – as if he were "beside himself," his consciousness shared.
Mark Twain summed up the twins' dilemma with customary insight and wit. Speaking to a journalist, he remarked that he had been born one member of a twin pair. Tragedy had struck soon after, however, when one of the twins, left unattended in the bathtub, drowned. As the two brothers were almost indistinguishable, even the parents had trouble telling who had died and who had survived. Years later, Twain delved into the circumstances of the event and came to examine the hospital records. In these he found that the attending physician had noted a birthmark on his brother's back. Now, since he, Mark Twain, knew of the existence of a birthmark on his own back, he was driven to a mind-bending conclusion. "It is he who survived," Twain declared. "I drowned."
A thought experiment brings the philosophical paradox of twins into still sharper relief. Imagine – it may someday even be technically possible – that a person is created who is identical to you in every way. This creature not only looks like you, but every particle in his body, down to the last atom, is in the same relative position and state. Every memory, every thought of your synthetic twin is the same at the instant of creation as your own. The moment the twin appears, what would it be like for you? Would you continue to be aware only of your old self looking out on the world from your old vantage point? Or would you now have a kind of dual consciousness, an awareness emanating from two different physical locations?
An initial reaction might be to suppose that you would be unaffected by the appearance of the twin. You would simply see an exact copy of yourself, be somewhat amazed at the experience, but then shrug your shoulders and carry on with life as if nothing untoward had happened. Your copy, meanwhile, would have his own distinct consciousness that, although it might feel exactly like yours, would be experienced by him alone.
This account fails, however, to do justice to the problem. The fact is, the replica of yourself would be as much "you" as you! To maintain absolute identity, we could arrange for the twin to materialize instantly facing you in the center of an empty, symmetrical room. His first sensory experience would then be the same as yours down to the last detail. There would be no difference whatsoever between you and him. Nor could you claim to be somehow privileged on the grounds that you were there first; the inescapable truth is, you would be on an equal footing from the moment the twin appeared. Given these conditions, if you insist that you would still be the "old you" and that your exactly identical twin would have a separate consciousness of his own (which you would not be privy to), then the onus is on you to explain how this could be so. Logically, because there would be no difference between you and your duplicate, there ought to be no difference in the experience of self; you would be he and he would be you. The implication is that your consciousness would be replicated along with your brain and body. You would effectively reside in two people at once.
Quite how this would feel is hard to say since it would be an experience unique in human history. But perhaps the often-reported shared mental bonds of real twins offer some clues. Identical twins frequently seem to know, intuitively, what is happening to the other, especially if one of the pair is in mortal danger. There are even stories of physical pain felt by one twin being somehow registered simultaneously by the other over great distances. Nor is this experience of shared consciousness necessarily confined to twins. Reports of people accurately sensing the death of close family members or friends, over thousands of miles, are not uncommon. Anecdotal though these accounts may be, they are evidently given in good faith and occur often enough to be taken seriously.
Returning to our thought experiment, what would happen next if the two exactly identical yous were to leave the room by different doors and enter an outside world that was highly asymmetrical? Say that one of the twins is driven off in a taxi and then flown to the Bahamas, while the other goes to an office job in the city. Thereafter they live entirely dissimilar lives. From the moment of departure from the symmetrical room, the experiences of the twins would begin to diverge so that their mental states and recently formed memories would also start to move apart. What would it feel like now to be you? Several possibilities present themselves, each with its problems.
The first is that you end up being both the twins. Your consciousness, in other words, is the sum consciousness of both individuals. This follows on from our earlier logic, but seems to run into increasing difficulties the longer the twins are apart. Different experiences will mold the twins in different ways, so that they become more and more distinguishable in their appearance and behavior. How can the twins be different people and the same person at the same time?
The second possibility is that you are just one of the twins, that is, what was you becomes once again localized within a single body. The trouble here is that your relationship to each of the twins leaving the room is exactly similar. Because of this there are no grounds for saying that you are one rather than the other.
The third option is that you are neither of the resultant people. But this is perhaps the least acceptable of all because it implies that by creating a copy of yourself you destroy the original!
On balance, we are led to admit that the first possibility – that two yous are created – is the most likely. However, by entertaining that it may be possible to replicate self-consciousness, we have begun to subtly alter our concept of the nature of self and of awareness as a whole.
Take another case. Imagine that in some far-future time, long after your death, an exact copy of you in your present state, reading this book, is manufactured. Would that "new you" really be you? Would it feel as if you had simply woken up after having "fallen asleep" at the point of death? Evidently not, since this new you would only have your present memories and neural connections and none of those which you will accumulate (or lose) between now and your death. Continuity of consciousness, then, would be ruled out. Would, instead, the new you feel exactly as you do now? This does not seem quite right either. The old you lived out his life and died. How can a new version of you be fashioned, through which you can live again with your consciousness "rewound" to some arbitrary point?
These strange thought experiments are not entirely without practical bearing. For those who have opted to be deep-frozen after death, the question of who is going to be inside their heads if and when they are ever revived is presumably of some concern. Leaving aside the monstrous technical problems of repairing or replacing tens of billions of badly damaged brain cells, there is the more delicate issue of what happens if the person who becomes conscious when the frozen brain is restored is not the same as the one who handed over his life-insurance policy to the cryonics company. Could the cryonaut's descendants sue? And if this reanimated person proves not to be the one that died, then exactly who is he? What would it be like for him or her suddenly to be made conscious, without a real past and, apparently, an identity to relate to?
Our appearance, abilities, memories, values, and opinions all contribute to making us the unique individuals we are. But there are other crucial aspects to being a "self": a stored impression of continuity and an awareness of existing at a single, forward-moving moment of time – the ever-present now.
"We" are constantly changing. We grow, age, add and lose memories, alter our opinions, become wiser or more foolish. Even the very particles of which we are made are continually being replaced – all are probably different now than they were, say, ten years ago. But it is not these objective qualities that lie at the heart of the mystery. It is the subjective, experiential side of self that proves so perplexing.
At forty, I look and think differently than when I was four or fourteen. Yet not only am I understood by others to be the same person, but I feel inwardly to be the same. My memories extend back in time linking me with that succession of younger men and boys who, though distinct in many ways, were still somehow "myself."
I go to sleep and self-awareness (except to some extent in dreams) shuts off. But there it is again when I awake. Because "I" am not there when self-consciousness is absent, I fail to notice the passage of time. Eight hours elapse while I am in bed but they are as nothing.
We do not fear losing consciousness if we can be reasonably assured of continuing where we left off when consciousness is restored. In this respect, both sleep, in which we spend about a third of our lives, and general anesthesia are acceptable. But, if it could be arranged, how would we feel about becoming our past or future selves? Then the prospect would seem more daunting. In such a situation, we would not be able to preserve our present cargo of memories or, more important, our present sense of self. It might be like becoming a stranger – and that is frightening, because to become someone else is to lose yourself.
That is precisely why we are afraid of dying. Death threatens to dissolve our selves permanently, a possibility we simply cannot come to grips with. What would it be like to be nothing? The Greek philosopher Lucretius pointed the way to an answer as early as the first century BC. The eternity after death, he said, is simply the mirror image of the eternity before birth. No one finds it disturbing to contemplate the prenatal state, so why should they be alarmed about the eternity to come? Fifteen billion years had already gone by before you appeared on the scene. But the wait was not terrifying because, to the "un-you," there was no wait. Likewise, if you permanently cease to exist in a few decades' time, you will not be around to worry about the billions of years to come. As far as you are concerned, the remaining span of the universe will be over in an instant. Seneca summed it up: "What is death? Either a transition or an end. I am not afraid of coming to an end, this being the same as never having begun, nor of transition, for I shall never be in confinement quite as cramped anywhere else as I am here."
And what about the process of dying itself, the actual transition from life to death? As the German philosopher Ludwig Wittgenstein reasoned: "Death is not an event in life; we do not experience death."
So, in fact, there is no rational basis at all for our fear of death. We shall either remain conscious in some form or feel nothing at all. And what is there to be afraid of in that? Yet, like someone who refuses to be consoled in the dentist's waiting room, most of us are afraid, enormously. We are terrified of the unknown and what it might be like not to have a self.
We build up the self to be something tremendously important, a solid, secure hub around which our lives can revolve. And yet how easily this feeling of self can be made to melt away. Turn on some of your favorite music or, better still, play it. Watch a good film, ride a switchback, make love, meditate. Where is your sense of self in the midst of any of these distractions? Self dissolves a thousand times a day, only to be quickly reconstituted from stored memories and a kind of neural bootstrap process; thus the brain works hard to keep the narrative or stream of consciousness flowing smoothly, convincing us of the continuity of our selves.
What happens, though, when that continuity is blown apart, by injury, disease, or psychological disorder? Then our familiar world can seem to collapse or fragment.
Documentary accounts such as The Three Faces of Eve, Sybil, and The Minds of Billy Milligan brought the extraordinary condition known as multiple personality into full public view. Through great psychological and physical trauma, such as extreme abuse as a child, it seems that a person's self can be made to break apart so that, effectively, more than one individual share the same brain. In the past, many psychiatrists dismissed "multiples" as clever fakes or misdiagnosed their condition as schizophrenia. But it seems clear now that the disorder, though quite rare, is indisputably real.
The first strong evidence that the various personalities of a sufferer are associated with genuinely distinct patterns of brain activity came in 1982. Frank Putnam, a psychiatrist working for the National Institute of Mental Health at Bethseda, Maryland, measured the "evoked potential," the brain response to a specific visual stimulus, for each of four personalities of ten patients. He found that while all the brain-wave patterns of the personalities, for a given patient, fell within the normal range, they were as different from one another as the patterns of two different human subjects.
We often wonder what it would be like to be someone else, to "get inside" another person's head. Those who are unfortunate enough to harbor multiple personalities know – though from their point of view the experience is far from desirable.
On one occasion, for instance, "Sybil" was waiting for an elevator in a hall at Columbia University, in New York City, only to find herself, apparently the next moment, outside, late at night in a strange, inhospitable neighborhood of a city she at first did not recognize. Five days had elapsed without her knowledge and she was in Philadelphia with a hotel key in her pocket that she had never seen before. She had flipped from her depleted core self into one of her fifteen alternative personalities and back again and knew nothing of the time for which "she" had been gone.
This, then is what it would be like to be a completely different person – nothing at all. If you were another person, then "you" would not be there to share or remember the experience. Upon becoming yourself again, it would be as if no time had passed. You can never know from another person's subjective viewpoint what it feels like to be him.
Victims of multiple personality disorder can receive psychiatric treatment to help overcome their condition. In time, the various sundered fragments of the individual can be brought back into common awareness again and merged. Thus the person’s self can once more be made whole. Physical damage to the brain, however, is often irreparable.
In The Man with a Shattered World, the psychiatrist A. R. Luria told the remarkable and deeply disturbing story of Lyova Zasetsky, a student who was called up following the German invasion of the Soviet Union. During the battle of Smolensk, in early 1943, Zasetsky was hit in the head by a machine-gun bullet. The injury and later complications destroyed large parts of his brain. At first he could remember nothing, not even his name, nor could he read or write or recognize anyone. "I seemed," he commented later, "to be some sort of newborn creature that just looked, listened, observed, repeated, but still had no mind of its own." Luria wrote: "He no longer had any sense of space, could not judge relationships between things, and perceived the world as broken into thousands of separate parts." It was as if Zasetsky the inner man had ceased to exist. As he wrote chillingly in his journal: "I was killed March 2, 1943."
Stroke, or more insidious conditions such as Alzheimer’s disease, can also permanently rob the brain of crucial functions, cutting us adrift from our future and our past. In some cases, when highly specific parts of the brain are affected, the results can be bizarre.
A rare condition called face agnosia impairs only a victim's ability to recognize faces, leaving all other mental functions intact. Neurologist Antonio Damasio, at the University of Iowa College of Medicine, has spent the past twenty years investigating such cases. He recalls, for instance, the plight of a female patient who, having suffered a stroke in the night, awoke unable to recognize the faces of her husband and daughter. Although she still knew who they were by their voices and mannerisms, their faces were like those of complete strangers to her. Damasio tested her powers of reasoning, memory, reading ability, and vision, and found them all to be normal. Yet she could no longer either identify or learn to identify the faces of relatives and friends she had known for years.
Using advanced scanning techniques, Damasio and his wife, Hanna, a neurologist and anatomist, have pinpointed the affected areas of the brain. These are what Damasio has christened "convergence zones" – regions in which circuits of neurons processing visual information merge with other streams of sensory data, such as the sound of someone's voice, the perceived tone of his skin or the appearance of his gestures. The convergence zones, in turn, are wired to higher centers in the brain handling memory function and storage.
The various levels of connections normally act in concert to produce that overall sense of familiarity we feel when we look at someone we know. But in victims of face agnosia, the recognition circuit is severed at some key junction. These people still retain the general concept of faces and the ability to understand and respond appropriately to such expressions as anger, sadness, and joy. "The breakdown," Damasio says, "is at the level of uniqueness."
To test his conclusions, Damasio used an instrument akin to a lie detector to measure the skin conductance responses of four patients suffering from acute face agnosia. He showed his subjects a series of photos of people they knew well. In every case, the patients reacted in a way which showed that some form of recognition was taking place at a subconscious level, even though they couldn't say out loud to whom the faces belonged.
Damasio believes such subconscious activity may be the trigger that, in most of us, starts off a chain reaction of orchestrated responses that ultimately results in us identifying a particular face. "Recognition in the true sense must be conscious," he asserts.
In a more extreme condition, known as "blind sight," victims report having no sense of vision at all. However, tests reveal that not only are their eyes working perfectly well, but the fine bundles of neurons joining the retinas to the appropriate regions in the visual cortex are also correctly in place. Again, the break in the system seems to be at a higher, integrative level where the various aspects of a visual field come together before being presented, neatly packaged, to our awareness. Eerily, blind-sight patients can see but don't know it.
The more we learn about the brain, the more it seems "we" are cast in the role of passengers rather than pilots. So much goes on automatically without "our" involvement. The latest scan techniques reveal the brain to be like a society of specialists whose existence we would never normally suspect. One particular grape-sized region deals only with regular verbs, another with irregular verbs. The degree of specialization is that great. Yet, after many stages of cross-connection and convergence, all these diverse aspects of processing and perception are brought together as a unified consciousness. And there, at the top of the hierarchy, doing the watching, is our self. We have this impression from the inside, of being an entity that sits apart from the brainworks like a spectator at a ball game. But, in fact, "we" are smeared all over the brain. The self as a fixed, central observer is an illusion, a phantasm that through malfunction of its supporting structure can be diminished or destroyed.
An important part of our experience of self is our ability to project backward in time, to lay down and access memories at will. But what happens when that recall ability is lost?
Clive Wearing once enjoyed an international reputation as a specialist in Renaissance music. But in 1985 he was struck down by a rare brain infection caused by herpes simplex, the same virus responsible for cold sores. As a result, large numbers of neurons, especially in his hippocampal lobes, were wiped out. Lying deep within the brain, the hippocampus works to consolidate recently acquired information, turning short-term memory into long-term. Deprived of this vital midway station between the cortex and the more primal regions of the brain, Clive Wearing lost his sense of past time. As his wife explains: "Clive's world now consists of a moment, with no past to anchor it to and no future to look forward to." Every minute of every day he is under the illusion of having just woken from a deep sleep – a situation his diary graphically reveals:
9:04 A.M. Now I am AWAKEClive Wearing suffers from Korsakoff's syndrome, a condition first documented by the Russian physician of that name in 1887. In this nightmarish state, victims lose the ability to lay down new memories and, as a result, are effectively trapped in time. The consequences can be bizarre, as Oliver Sacks describes in his book The Man Who Mistook His Wife for a Hat. For example, there was the case of "Mr. Thompson": "He remembered nothing for more than a few seconds. He was completely disoriented. Abysses of amnesia continually opened up beneath him, but he would bridge them, mainly by fluent confabulations and fictions of all kinds. For him they were not fictions, but how he suddenly saw or interpreted the world... [He] must literally make himself and his world up every moment."
10:00 A.M. NOW I AM AWAKE
10:28 A.M. ACTUALLY I AM NOW FIRST TIME AWAKE for years
10:54 A.M. Now I am awake for the first time
Cases such as these speak of more than just the fragile and constructed nature of self. They raise serious questions about the nature of time and of the delicate connection between psychological time and physical reality. Could it be that time, like self, is nothing more than a product of the way we think?
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