Blue Mars (77 page)

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Authors: Kim Stanley Robinson

Tags: #Science Fiction - Space Opera, #Fiction - Science Fiction, #Mars (Planet), #Space Opera, #Fiction, #Science Fiction, #Science Fiction - General, #Planets, #Life on other planets, #General

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“Of course,” Maya said, absorbed in the sight of the sunset.

He needed a simpler problem. As a postponement, as a step toward
the harder problems; or just as something he could solve. Memory, perhaps.
Fighting the blank-outs; it was certainly a problem that stood at hand, ready
for study. His memory was in need of help. Working on it might even cast light
on the quick decline. And even if it didn’t, he had to try it, no matter how
hard it was. Because they were all going to die; but they could at least die
with their memories intact.

So he switched his emphasis to the memory problem, abandoning the
quick decline and all the rest of the senescence issues. He was only mortal
after all.

 

 

 

 

 

Recent memory work was fairly suggestive
of avenues of approach. This particular
scientific front was related in some of its aspects to the work on learning
that had enabled Sax to (partially) recover from his stroke. This was not
surprising, as memory was the retention of learning. All brain science tended
to move together in its understanding of consciousness. But in that
progression, retention and recall remained recalcitrant crux issues, still
imperfectly understood.

But there were indications, and more all the time. Clinical clues;
a lot of the ancient ones were experiencing memory problems of varying kinds,
and behind the ancient ones came a giant generation of nisei, who could see the
problems manifesting in their elders, and hoped to avoid them. So memory was a
hot topic. Hundreds, indeed thousands of labs were working on it in one way or
another, and as a result many aspects of it were coming clear. Sax immersed
himself in the literature in his usual style, reading intensively for several
months on end; and at the end of that time he thought he could say, in general
terms, how memory worked; although in the end he, like all the rest of the
scientists working on the problem, ran into their insufficient understanding of
the underlying basics—of consciousness, matter, time. And at this point, as
detailed as their understanding was, Sax could not see how memory might be
improved or reinforced. They needed something more.

The original Hebb hypothesis, first proposed by Donald Hebb in
1949, was still held to be true, because it was such a general principle;
learning changed some physical feature in the brain, and after that the changed
feature somehow encoded the event learned. In Hebb’s time the physical feature
(the engram) was conceived of as occurring somewhere on the synaptic level, and
as there could be hundreds of thousands of synapses for each of the ten billion
neurons in the brain, this gave researchers the impression that the brain might
be capable of holding some 1014 data bits; at the time this seemed more than
adequate to explain human consciousness. And as it was also within the realm of
the possible for computers, it led to a brief vogue in the notion of strong
artificial intelligence, as well as that era’s version of the “machine
fallacy,” a variant of the pathetic fallacy, in which the brain was thought of
as being something like the most powerful machine of the time. The work of the
twenty-first and twenty-second century, however, had made it clear that there
were no specific “engram” sites as such. Any number of experiments failed to
locate these sites, including one in which various parts of rat’s brains were
removed after they learned a task, with no part of the brain proving essential;
the frustrated experimenters concluded that memory was “everywhere and
nowhere,” leading to the analogy of brain to hologram, even sillier than all
the other machine analogies; but they were stumped, they were flailing. Later
experiments clarified things; it became obvious that all the actions of
consciousness were taking place on a level far smaller even than that of
neurons; this was associated in Sax’s mind with the general miniaturization of
scientific attention through the twenty-second century. In that finer-grained
appraisal they had begun investigating the cytoskeletons of neuron cells, which
were internal arrays of microtubules, with protein bridges between the
microtubules. The microtubules’ structure consisted of hollow tubes made of
thirteen columns of tubulin dimers, peanut-shaped globular protein pairs, each
about eight-by-four-by-four nanometers, existing in two different
configurations, depending on their electrical polarization. So the dimers
represented a possible on-off switch of the hoped-for engrain; but they were so
small that the electrical state of each dimer was influenced by the dimers
around it, because of van der Waals interactions between them. So messages of
all kinds could be propagated along each mi-crotubule column, and along the
protein bridges connecting them. Then most recently had come yet another step
in miniaturization: each dimer contained about 450 amino acids, which could
retain information by changes in the sequences of amino acids. And contained
inside the dimer columns were tiny threads of water in an ordered state, a
state called vicinal water, and this vicinal water was capable of conveying
quantum-coherent oscillations for the length of the tubule. A great number of
experiments on living monkey brains, with miniaturized instrumentation of many
different kinds, had established that while consciousness was thinking,
amino-acid sequences were shifting, tub-ulin dimers in many different places in
the brain were changing configuration, in pulsed phases; microtubules were
moving, sometimes growing; and on a much larger scale, dendrite spines then
grew and made new connections, sometimes changing synapses permanently,
sometimes not.

So now the best current model had it that memories were encoded
(somehow) as standing patterns of quantum-coherent oscillations, set up by
changes in the microtubules and their constituent parts, all working in
patterns inside the neurons. Although there were now researchers who speculated
that there could be significant action at even finer ultramicroscopic levels,
permanently beyond their ability to investigate (familiar refrain); some saw
traces of signs that the oscillations were structured in the kind of
spin-network patterns that Bao’s work described, in knotted nodes and networks
that Sax found eerily reminiscent of the palace-of-memory plan, utilizing rooms
and hallways, as if the ancient Greeks by introspection alone had intuited the
very geometry of timespace.

In any case, it was sure that these ultramicroscopic actions were
implicated in the brain’s plasticity; they were part of how the brain learned
and then remembered. So memory was happening at a far smaller level than had
been previously imagined, which gave the brain a much higher computational
possibility than before, up to perhaps 1024 operations per second—or even 1043
in some calculations, leading one researcher to note that every human mind was
in a certain sense more complicated that all the rest of the universe (minus
its other consciousnesses, of course). Sax found this suspiciously like the
strong anthropic phantoms seen elsewhere in cosmological theory, but it was an
interesting idea to contemplate.

So, not only was there simply more going on, it was also happening
at such fine levels that quantum effects were certainly involved.
Experimentation had made it clear that large-scale collective quantum phenomena
were happening in every brain; there existed in the brain both global quantum
coherence, and quantum entanglement between the various electrical states of
the microtubules; and this meant that all the counterintuitive phenomena and
sheer paradox of quantum reality were an integral part of consciousness. Indeed
it was only very recently, by including the quantum effects in the
cytoskeletons, that a team of French researchers had finally managed to put
forth a plausible theory as to why general anesthetics worked, after all the
centuries of blithely using them.

So they were confronted with yet another bizarre quantum world, in
which there was action at a distance, in which decisions not made could affect
events that really happened, in which certain events seemed to be triggered
tel-eologically, that is to say by events that appeared to come after them in
time. . . . Sax was not greatly surprised by this development. It supported a
feeling he had had all his life, that the human mind was deeply mysterious, a
black box that science could scarcely investigate. And now that science was
investigating it, it was coming up hard against the great unexplainables of
reality itself.

Still, one could hold to what science had learned; and admit that
reality at the quantum level behaved in ways that were simply outrageous at the
level of human senses and ordinary experience. They had had three hundred years
to get used to that, and eventually they had somehow to incorporate this
knowledge into their worldviews, and forge on. Sax would have indeed said that
he was comfortable with the familiar quantum paradoxes; things at the
micros-cale were bizarre but explicable, quantifiable or at least de-scribable,
using complex numbers, Riemannian geometry, and all the rest of the armatures
of the appropriate branches of mathematics. Finding such stuff in the very
workings of the brain should have been no surprise at all. Indeed, compared to
things like human history or psychology or culture, it was even somehow
comforting. It was only quantum mechanics after all. Something that could be
modeled by mathematics. And that was saying something.

So. At an extremely fine level of structure in the brain, much of
one’s past was contained, encoded in a unique complex network of synapses,
microtubules, dimers and vicinal water and amino-acid chains, all small enough
and near enough together to have quantum effects on each other. Patterns of
quantum fluctuation, diverging and collapsing; this was consciousness. And the
patterns were clearly held or generated in specific parts of the brain; they
were the result of a physical structure articulated on many levels. The
hippocampus, for instance, was critically important, especially the dentate
gyrus region and the perforant pathway nerves that led to it. And the
hippocampus was extremely sensitive to action in the limbic system, directly
underneath it in the brain; and the limbic system was in many ways the seat of
the emotions, what the ancients would have called the heart. Thus the emotional
charge of an event had much to do with how fully it was laid out in the memory.
Things happened, and the consciousness witnessed or experienced them, and
inevitably a great deal of this experience changed the brain, and became part
of it forever; particularly the events heightened by emotion. This description
seemed right to Sax; what he had felt most he remembered best—or forgot most
assiduously, as certain experiments suggested, with an unconscious constant
effort that was not true forgetting at all, but repression.

After that initial change in the brain, however, the slow process
of degradation began. For one thing, the power of recollection was different in
different people, but always less powerful than memory storage, it appeared,
and very hard to direct. So much was patterned into the brain but never
retrieved. And then if one never remembered a pattern, never recollected and
rehearsed it, then they never got the reinforcement of another run-through; and
after about 150 years of storage, experiments suggested, the pattern began to
degrade more and more rapidly, due apparently to the accumulated quantum
effects of free radicals collecting randomly in the brain. This was apparently
what was happening to the ancient ones; a breakdown process which began
immediately after an event was patterned into the brain, eventually hit a
cumulative level where the effects were catastrophic for the oscillatory
patterns involved, and thus for the memories. It was probably about as
clocklike, Sax thought glumly, as the thermodynamic clouding of the lens of the
eye.

However—if one could rehearse all one’s memories, ec-phorize them
as some called it in the literature on the subject—from the Greek, meaning
something like “echo transmission”—then it would reinforce the patterns, giving
them a fresh start and setting the clock of degradation back to zero. A sort of
longevity treatment for dimer patterns, in effect, sometimes referred to in the
literature as anamnesis, or loss of forgetting. And after such treatment it
would be easier to recall any given event, or at least as easy as it had been
soon after the event happened. This was the general direction that work in
memory reinforcement was taking. Some called the drugs and electrical devices
involved in this process nootropics, a word which Sax read as “acting upon mind.”
There were a lot of terms for the process being bandied about in the current
literature, people scrambling through their Greek and Latin lexicons in the
hope of becoming the namer of the phenomenon: Sax had seen mnemonics and
mnemonistics, and mnemosynics, after the goddess of memory; also
mimenskesthains, from the Greek verb “to remember.” Sax preferred memory
reinforcer, although he also liked anamnesis, which seemed the most accurate
term for what they were trying to do. He wanted to concoct an anamnestic.

But the practical difficulties of ecphorization—of remembering all
one’s past, or even some particular part of it— were great. Not just finding
the anamnestics that might stimulate such a process, but finding as well the
time it would take! When one had lived two centuries, it seemed possible that
it might take years to ecphorize all the significant events of one’s life.

Clearly a sequential chronological run-through was impractical, in
more ways than one. What would be preferable was some kind of simultaneous
flushing of the system, strengthening the entire network without consciously
remembering every component of it. Whether such a flushing was
electrochemically possible was unclear; and what such a flushing might feel
like was impossible to imagine. But if one were to electrically stimulate the
perforant pathway to the hippocampus, and get a great deal of adenosine
tri-phosphate past the blood-brain barrier, for instance, thus stimulating the
long-term potentiation that aided learning in the first place; and then impose
a brain-wave pattern stimulating and supporting the quantum oscillations of the
microtubules; and then direct one’s consciousness to review the memories that
felt most important to one, while the rest were being reinforced as well,
unconsciously....

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