The most inexplicable things will brew in any mind.
Because the body is plainly a collection of specialist organs-heart
for pumping, kidneys for cleaning -- no one was too surprised to discover
that the mind delegates cognitive matters to different regions of the
In the late 1800s, physicians noted correlations in recently
deceased patients between damaged areas of the brain and obvious
impairments in their mental abilities just before death. The connection
was more than academic: might insanity be biological in origin? At the
West Riding Lunatic Asylum, London, in 1873, a young physician who
suspected so surgically removed small portions of the brain from two
living monkeys. In one, his incision caused paralysis of the right
limbs; in the other he caused deafness. But in all other respects, both
monkeys were normal. The message was clear: the brain must be
compartmentalized. One part could fail without sinking the whole vessel.
If the brain was in departments, in what section were recollections
stored? In what way did the complex mind divvy up its chores? In a most
In 1888, a man who spoke fluently and whose memory was sharp found
himself in the offices of one Dr. Landolt, frightened because he could
no longer name any letters of the alphabet. The perplexed man could
write flawlessly when dictated a message. However, he could not reread
what he had written nor find a mistake if he had made one. Dr. Landolt
recorded, "Asked to read an eye chart, [he] is unable to name any
letter. However he claims to see them perfectly....He compares the A to
an easel, the Z to a serpent, and the P to a buckle."
The man's word-blindness degenerated to a complete aphasia of both
speech and writing by the time of his death four years later. Of course,
in the autopsy, there were two lesions: an old one near the occipital
(visual) lobe and a newer one probably near the speech center.
Here was remarkable evidence of the bureaucratization of the brain.
In a metaphorical sense, different functions of the brain take place in
different rooms. This room handles letters, if spoken; that room,
letters, if read. To speak a letter (outgoing), you need to apply to yet
another room. Numbers are handled by a different department altogether,
in the next building. And if you want curses, as the Monty Python Flying
Circus skit reminds us, you'll need to go down the hall.
An early investigator of the brain, John Hughlings-Jackson, recounts
a story about a woman patient of his who lived completely without
speech. When some debris, which had been dumped across the street from
the ward where she lived, ignited into flames, the patient uttered the
first and only word Hughlings-Jackson had ever heard her say: "Fire!"
How can it be, he asked somewhat incredulous, that "fire" is the
only word her word department remembers? Does the brain have its own
"fire" department, so to speak?
As investigators probed the brain further, the riddle of the mind
revealed itself to be deeply specific. The literature on memory features
people ordinary in their ability to distinguish concrete nouns -- tell them
"elbow" and they will point to their elbow -- but extraordinary in their
inability to distinguish abstract nouns -- ask them about "liberty" or
"aptitude" and they stare blankly and shrug. Contrarily, the minds of
other apparently normal individuals have lost the ability to retain
concrete nouns, while perfectly able to identify abstract things. In his
wonderful and overlooked book The Invention of Memory, Israel Rosenfield
One patient, when asked to define hay, responded, "I've forgotten";
and when asked to define poster, said, "no idea." Yet given the word
supplication, he said, "making a serious request for help," and pact
drew "friendly agreement."
Memory is a palace, say the ancient philosophers, where every room parks
a thought. Yet with every clinical discovery of yet another form of
specialized forgetfulness, the rooms of memory exploded in number. Down
this road there is no end. Memory, already divided into a castle of
chambers, balkanizes into a terrifying labyrinth of tiny closets.
One study pointed to four patients who could discern inanimate
objects (umbrella, towel), but garbled living things, including foods!
One of these patients could converse about nonliving objects without
suspicion, but a spider to him was defined as "a person looking for
things, he was a spider for a nation." There are records of aphasias
that interfere with the use of the past tense. I've heard of another
report (one that I cannot confirm, but one that I don't doubt) of an
ailment that allows a person to discern all foods except vegetables.
The absurd capriciousness underlying such a memory system is best
represented by the categorization scheme of an ancient Chinese
encyclopedia entitled Celestial Emporium of Benevolent Knowledge, as
interpreted by the South American fiction master J. L. Borges.
On those remote pages it is written that animals are divided into
(a) those that belong to the Emperor, (b) embalmed ones, (c) those that
are trained, (d) suckling pigs, (e) mermaids, (f) fabulous ones, (g)
stray dogs, (h) those that are included in this classification, (i)
those that tremble as if they were mad, (j) innumerable ones, (k) those
drawn with a very fine camel's hair brush, (l) others, (m) those that
have just broken a flower vase, (n) those that resemble flies from a
As farfetched as the Celestial Emporium system is, any classification
process has its logical problems. Unless there is a different location
for every memory to be filed in, there will need to be confusing
overlaps, say for instance, of a talking naughty pig, that may be filed
under three different categories above. Filing the thought under all
three slots would be highly inefficient, although possible.
The system by which knowledge is sequestered in our brain became
more than just an academic question as computer scientists tried to
build an artificial intelligence. What is the architecture of memory in
a hive mind?
In the past most researchers leaned toward the method humans
intuitively use for their own manufactured memory stashes: a single
location for each archived item, with multiple cross-referencing, such
as in libraries. The strong case for a single location in the brain for
each memory was capped by a series of famously elegant experiments made
by Wilder Penfield, a Canadian neurosurgeon working in the 1930s. In
daring open-brain surgery, Penfield probed the living cerebellum of
conscious patients with an electrical stimulant, and asked them to
report what they experienced. Patients reported remarkably vivid
memories. The smallest shift of the stimulant would generate distinctly
separate thoughts. Penfield mapped the brain location of each memory
while he scanned the surface with his probe.
His first surprise was that these recollections appeared repeatable,
in what years later would be taken as a model of a tape recorder -- as in:
"hit replay." Penfield uses the term "flash-back" in his account of a
26-year-old woman's postepileptic hallucination: "She had the same
flash-back several times. These had to do with her cousin's house or the
trip there -- a trip she has not made for ten to fifteen years but used to
make often as a child."
The result of Penfield's explorations into the unexplored living
brain produced the tenacious image of the hemispheres as fabulous
recording devices, ones that seemed to rival the fantastic recall of the
newly popular phonograph. Each of our memories was delicately etched
into its own plate, catalogued and filed faithfully by the temperate
brain, and barring violence, could be retrieved like a jukebox song by
pushing the right buttons.
Yet, a close scrutiny of Penfield's raw transcripts of his probing
experiments shows memory to be a less mechanical process. As one
example, here are some of the responses of a 29-year-old woman to
Penfield's pricks in her left temporal lobe: "Something coming to me
from somewhere. A dream." Four minutes later, in exactly the same spot:
"The scenery seemed to be different from the one just before..." In a
nearby spot: "Wait a minute, something flashed over me, something I
dreamt." In a third spot: further inside the brain, "I keep having
dreams." The stimulation is repeated in the same spot: "I keep seeing
things -- I keep dreaming of things."
These scripts tell of dreamlike glimpses, rather than disorienting
reruns dredged up from the basement cubbyholes of the mind's archives.
The owners of these experiences recognize them as fragmentary
semimemories. They ramble with that awkward "assembled" flavor that
dreams grow by -- unfocused tales of bits and pieces of the past reworked
into a collage of a dream. The emotional charge of a dŽjˆ vu was absent.
No overwhelming sense of "it was exactly like this was then" pushed
against the present. The replays should have fooled nobody.
Human memories do crash. They crash in peculiar ways, by forgetting
vegetables on a list of things to buy at the grocery or by forgetting
vegetables in general. Memories often bruise in tandem with a physical
bruise of the brain, so we must expect that some memory is bound in time
and space to some degree, since being bound to time and space is one
definition of being real.
But the current view of cognitive science leans more toward a new
image: memories are like emergent events summed out of many discrete,
unmemory-like fragments stored in the brain. These pieces of
half-thoughts have no fixed home; they abide throughout the brain. Their
manner of storage differs substantially from thought to thought-learning
to shuffle cards is organized differently than learning the capital of
Bolivia -- and the manner differs subtly from person to person, and
equally subtly from time to time.
There are more possible ideas/experiences than there are ways to
combine neurons in the brain. Memory, then, must organize itself in some
way to accommodate more possible thoughts than it has room to store. It
cannot have a shelf for every thought of the past, nor a place reserved
for every potential thought of the future.
I remember a night in Taiwan twenty years ago. I was in the back of
an open truck on a dirt road in the mountains. I had my jacket on; the
hill air was cold. I was hitching a ride to arrive at a mountain peak by
dawn. The truck was grinding up the steep, dark road while I looked up
to the stars in the clear alpine air. It was so clear that I could see
tiny stars near the horizon. Suddenly a meteor zipped across low, and
because of my angle in the mountains, I could see it skip across the
atmosphere. Skip, skip, skip, like a stone.
As I just now remembered this, the skipping meteor was not a memory
tape I replayed, despite its ready vividness. The skipping meteor image
doesn't exist anywhere in particular in my mind. When I resurrected my
experience, I assembled it anew. And I assemble it anew each time I
remember it. The parts are tiny bits of evidence scattered sparsely
through the hive of my brain: a record of cold shivering, of a bumpy
ride somewhere, of many sightings of stars, of hitchhiking. The records
are even finer grained than that: cold, bump, points of light, waiting.
They are the same raw impressions our minds receive from our senses and
with which it assembles our perceptions of the present.
Our consciousness creates the present, just as it creates the past,
from many distributed clues scattered in our mind. Standing before an
object in a museum, my mind associates its parallel straight lines with
the notion of a "chair," even though the thing has only three legs. My
mind has never before seen such a chair, but it compiles all the
associations -- upright, level seat, stable, legs-and creates the visual
image. Very fast. In fact, I will be aware of the general "chairness"
of the chair before I can perceive its unique details.
Our memories (and our hive minds) are created in the same
indistinct, haphazard way. To find the skipping meteor, my consciousness
grabbed a thread with streaks of light and gathered a bunch of feelings
associated with stars, cold, bumps. What I created depended on what else
I had thrown into my mind recently, including what other thing I was
doing/feeling last time I tried to assemble the skipping meteor memory.
That's why the story is slightly different each time I remember it,
because each time it is, in a real sense, a completely different
experience. The act of perceiving and the act of remembering are the
same. Both assemble an emergent whole from many distributed pieces.
"Memory," says cognitive scientist Douglas Hofstadter, "is highly
reconstructive. Retrieval from memory involves selecting out of a vast
field of things what's important and what is not important, emphasizing
the important stuff, downplaying the unimportant." That selection
process is perception. "I am a very big believer," Hofstadter told me,
"that the core processes of cognition are very, very tightly related to
In the last two decades, a few cognitive scientists have
contemplated ways to create a distributed memory. Psychologist David
Marr proposed a novel model of the human cerebellum in the early 1970s
by which memory was stored randomly throughout a web of neurons. In
1974, Pentti Kanerva, a computer scientist, worked out the mathematics
of a similar web by which long strings of data could be stored randomly
in a computer memory. Kanerva's algorithm was an elegant method to store
a finite number of data points in a very immense potential memory space.
In other words, Kanerva showed a way to fit any perception a mind could
have into a finite memory mechanism. Since there are more ideas possible
in the universe than there are atoms or minutes, the actual ideas or
perceptions that a human mind can ever get to are relatively sparse
within the total possibilities; therefore Kanerva called his technique a
"sparse distributed memory" algorithm.
In a sparse distributed network, memory is a type of perception. The
act of remembering and the act of perceiving both detect a pattern in a
very large choice of possible patterns. When we remember, we re-create
the act of the original perception; that is, we relocate the pattern by
a process similar to the one we used to perceive the pattern originally.
Kanerva's algorithm was so mathematically clean and crisp that it
could be roughly implemented by a hacker into a computer one afternoon.
At the NASA Ames Research Center, Kanerva and colleagues fine-tuned his
scheme for a sparse distributed memory in the mid-1980s by designing a
very robust practical version in a computer. Kanerva's memory algorithm
could do several marvelous things that parallel what our own minds can
do. The researchers primed the sparse memory with several degraded
images of numerals (1 to 9) drawn on a 20-by-20 grid. The memory stored
these. Then they gave the memory another image of a numeral more
degraded than the first samples to see if it could "recall" what the
digit was. The memory could. It honed in on the prototypical shape that
was behind all the degraded images. In essence it remembered a shape it
had never seen before!
The breakthrough was not just being able to find or replay something
from the past, but to find something in a vast hive of possibilities
when only the vaguest clues are given. It is not enough to retrieve your
grandmother's face; a memory must identify it when you see her profile
in a wholly different light and from a different angle.
A hive mind is a distributed memory that both perceives and
remembers. It is possible that a human mind may be chiefly distributed,
yet, it is in artificial minds where distributed mind will certainly
prevail. The more computer scientists thought about distributing
problems into a hive mind, the more reasonable it seemed. They figured
that most personal computers are not in actual use most of the time they
are turned on! While composing a letter on a computer you may interrupt
the computer's rest with a short burst of key pounding and then let it
return to idleness as you compose the next sentence. Taken as a whole,
the turned-on computers in an office are idle a large percentage of the
day. The managers of information systems in large corporations look at
the millions of dollars of personal computer equipment sitting idle on
workers' desks at night and wonder if all that computing power might not
be harnessed. All they would need is a way to coordinate work and memory
in a very distributed system.
But merely combating idleness is not what makes distributing
computing worth doing. Distributed being and hive minds have their own
rewards, such as greater immunity to disruption. At Digital Equipment
Corporation's research lab in Palo Alto, California, an engineer
demonstrated this advantage of distributed computation by opening the
door of the closet that held the company's own computer network and
dramatically yanking a cable out of its guts. The network instantly
routed around the breach and didn't falter a bit.
There will still be crashes in any hive mind, of course. But because
of the nonlinear nature of a network, when it does fail we can expect
glitches like an aphasia that remembers all foods except vegetables. A
broken networked intelligence may be able to calculate pi to the
billionth digit but not forward e-mail to a new address. It may be able
to retrieve obscure texts on, say, the classification procedures for
African zebra variants, but be incapable of producing anything sensible
about animals in general. Forgetting vegetables in general, then, is
less likely a failure of a local memory storage place than it is a
systemwide failure that has, as one of its symptoms, the failure of a
particular type of vegetable association -- just as two separate but
conflicting programs on your computer hard disk may produce a "bug" that
prevents you from printing words in italic. The place where the italic
font is stored is not broken; but the system's process of rendering
italic is broken.
Some of the hurdles that stand in the way of fabricating a
distributed computer mind are being overcome by building the network of
computers inside one box. This deliberately compressed distributed
computing is also known as parallel computing, because the thousands of
computers working inside the supercomputer are running in parallel.
Parallel supercomputers don't solve the idle-computer-on-the-desk
problem, nor do they aggregate widespread computing power; it's just
that working in parallel is an advantage in and of itself, and worth
building a million-dollar stand-alone contraption to do it.
Parallel distributed computing excels in perception, visualization,
and simulation. Parallelism handles complexity better than traditional
supercomputers made of one huge, incredibly fast serial computer. But in
a parallel supercomputer with a sparse, distributed memory, the
distinction between memory and processing fades. Memory becomes an
reenactment of perception, indistinguishable from the original act of
knowing. Both are a pattern that emerges from a jumble of interconnected