IS YOUR DANGEROUS IDEA?"
Mechanical Engineer, MIT
genetic breakthrough that made people capable of ideas
most dangerous idea is the genetic breakthrough that made
people capable of ideas themselves. The idea of ideas is
nice enough in principle; and ideas certainly have had their
impact for good. But one of these days one of those nice
ideas is likely to have the unintended consequence of destroying
everything we know.
we cannot not stop creating and exploring new ideas: the
genie of ingenuity is out of the bottle. To suppress the
power of ideas will hasten catastrophe, not avert it. Rather,
we must wield that power with the respect it deserves.
risks no danger reaps no reward.
Planetary Scientist; Cassini Imaging
Science Team Leader; Director CICLOPS, Boulder
CO; Adjunct Professor, University of Colorado,
University of Arizona
Greatest Story Ever Told
confrontation between science and formal religion will come
to an end when the role played by science in the lives of
all people is the same played by religion today.
just what is that?
the heart of every scientific inquiry is a deep spiritual
— to grasp, to know, to feel connected through an understanding
of the secrets of the natural world, to have a sense of one's
part in the greater whole. It is this inchoate desire for connection
to something greater and immortal, the need for elucidation
of the meaning of the 'self', that motivates the religious
to belief in a higher 'intelligence'. It is the allure of a
bigger agency — outside the self but also involving,
protecting, and celebrating the purpose of the self — that
is the great attractor. Every culture has religion. It undoubtedly
satisfies a manifest human need.
the same spiritual fulfillment and connection can be found
in the revelations of science. From energy to matter, from
fundamental particles to DNA, from microbes to Homo sapiens,
from the singularity of the Big Bang to the immensity of
the universe .... ours is the greatest story ever told. We
scientists have the drama, the plot, the icons, the spectacles,
the 'miracles', the magnificence, and even the special effects.
We inspire awe. We evoke wonder.
And we don't have one god, we have many of them. We find gods
in the nucleus of every atom, in the structure of space/time,
in the counter-intuitive mechanisms of electromagneticsm. What
richness! What consummate beauty!
even exalt the `self'. Our script requires a broadening of
the usual definition, but we too offer hope for everlasting
existence. The `self' that is the particular, networked set
of connections of the matter comprising our mortal bodies
will one day die, of course. But the `self' that is the sum
of each separate individual condensate in us of energy-turned-matter
is already ancient and will live forever. Each fundamental
particle may one day return to energy, or from there revert
back to matter. But in one form or another, it will not cease.
In this sense, we and all around us are eternal, immortal,
and profoundly connected. We don't have one soul; we have
trillions upon trillions of them.
are reasons enough for jubilation ... for riotous, unrestrained,
what are we missing?
lack ceremony. We lack ritual. We lack the initiation of
baptism, the brotherhood of communal worship.
have no loving ministers, guiding and teaching the flocks
in the ways of the 'gods'. We have no fervent missionaries,
no loyal apostles. And we lack the all-inclusive ecumenical
embrace, the extended invitation to the unwashed masses.
Alienation does not warm the heart; communion does.
what if? What if we appropriated the craft, the artistry,
the methods of formal religion to get the message across?
Imagine 'Einstein's Witnesses' going door to door or TV evangelists
passionately espousing the beauty of evolution.
a Church of Latter Day Scientists where believers could gather.
Imagine congregations raising their voices in tribute to
gravity, the force that binds us all to the Earth, and the
Earth to the Sun, and the Sun to the Milky Way. Or others
rejoicing in the nuclear force that makes possible the sunlight
of our star and the starlight of distant suns. And can't
you just hear the hymns sung to the antiquity of the universe,
its abiding laws, and the heaven above that 'we' will all
one day inhabit, together, commingled, spread out like a
nebula against a diamond sky?
day, the sites we hold most sacred just might be the astronomical
observatories, the particle accelerators, the university
research installations, and other laboratories where the
high priests of science — the biologists, the physicists,
the astronomers, the chemists — engage in the noble
pursuit of uncovering the workings of nature herself. And
today's museums, expositional halls, and planetaria may then
become tomorrow's houses of worship, where these revealed
truths, and the wonder of our interconnectedness with the
cosmos, are glorified in song by the devout and the soulful.
they will sing. "May the force be with you!"
writer; Former cast member of "The Monkees";
A Trustee and President of the Gihon Foundation and
a Trustee and Vice-Chair of the American Film Institute
is Non-Time, Non-Sequential, and Non-Objective
a dangerous idea per se but like a razor sharp tool in unskilled
hands it can inflect unintended damage.
drives forward the notion the past does not create the present.
This would of course render evolutionary theory a local-system,
near-field process that was non-causative (i.e. effect).
reverberates through the Turing machine and computation,
and points to simultaneity. It redefines language and cognition.
establishes a continuum not to be confused with solipsism.
As Schrödinger puts it when discussing the "time-hallowed
discrimination between subject and object" — "the
world is given to me only once, not one existing and one
perceived. Subject and object are only one. The barrier between
them cannot be said to have broken down as a result of recent
experience in the physical sciences, for this barrier does
not exist". This continuum has large implications for
the empirical data set, as it introduces factual infinity
into the data plane.
three notions, Non-Time, Non-sequence, and Non-Object have
been peeking like diamonds through the dust of empiricism,
philosophy, and the sciences for centuries. Quantum mechanics,
including Deutsch's parallel universes and the massive parallelism
of quantum computing, is our brightest star — an unimaginably
tall peak on our fitness landscape.
bring us to a threshold over which empiricism has yet to
travel, through which philosophy must reconstruct the very
idea of ideas, and beyond which stretches the now familiar "uncharted
territories" of all great adventures.
Case Western Reserve University; Author, Hiding
in the Mirror
world may fundamentally be inexplicable
has progressed for 400 years by ultimately explaining observed
phenomena in terms of fundamental theories that are rigid. Even
minor deviations from predicted behavior are not allowed
by the theory, so that if such deviations are observed,
these provide evidence that the theory must be modified,
usually being replaced by a yet more comprehensive theory
that fixes a wider range of phenomena.
ultimate goal of physics, as it is often described, is
to have a "theory of everything", in which all
the fundamental laws that describe nature can neatly
be written down on the front of a T-shirt (even if the
T-shirt can only exist in 10 dimensions!). However, with
the recognition that the dominant energy in the universe
resides in empty space — something that is so peculiar
that it appears very difficult to understand within the context
theoretical ideas we now possess — more physicists have
been exploring the idea that perhaps physics is an 'environmental
science', that the laws of physics we observe are merely
accidents of our circumstances, and
that an infinite number of different universe could exist with
different laws of physics.
is true even if there does exist some fundamental candidate
mathematical physical theory. For example, as is currently
in vogue in an idea related to string
theory, perhaps the fundamental theory allows an infinite number
of different 'ground state' solutions, each of which describes
a different possible universe with a consistent set of physical
laws and physical dimensions.
might be that the only way to understand why the laws
of nature we observe in our universe are the way they
are is to understand that if they were any different, then
life could not have arisen in our universe, and we would thus
not be here to measure them today.
is one version of the infamous "anthropic principle".
But it could actually be worse — it is equally
likely that many different combinations of laws would allow
life to form, and that it is a pure accident that the constants
of nature result in the combinations we experience in
our universe. Or, it could be that the mathematical
formalism is actually so complex so that the ground
states of the theory, i.e. the set of possible states
that might describe our universe, actually might not
this case, the end of "fundamental" theoretical physics
(i.e. the search for fundamental microphysical laws...there will
still be lots of work for physicists who try to understand
the host of complex phenomena occurring at a variety
of larger scales) might occur not via a theory of everything,
but rather with the recognition that all so-called fundamental
theories that might describe nature would be purely "phenomenological",
that is, they would be derivable from observational
phenomena, but would not reflect any underlying grand
mathematical structure of the universe
that would allow a basic understanding of why the universe
is the way it is.
Philosopher; University Professor, Co-Director, Center for
Cognitive Studies, Tufts University; Author, Darwin's
aren't enough minds to house the population explosion
can be dangerous. Darwin had one, for instance. We hold all
sorts of inventors and other innovators responsible for assaying,
in advance, the environmental impact of their creations,
and since ideas can have huge environmental impacts, I see
no reason to exempt us thinkers from the responsibility of
quarantining any deadly ideas we may happen to come across.
So if I found what I took to be such a dangerous idea, I
would button my lip until I could find some way of preparing
the ground for its safe expression. I expect that others
who are replying to this year's Edge question have
engaged in similar reflections and arrived at the same policy.
If so, then some people may be pulling their punches with
their replies. The really dangerous ideas they are
keeping to themselves.
here is an unsettling idea that is bound to be true in one
version or another, and so far as I can see, it won't hurt
to publicize it more. It might well help.
human population is still growing, but at nowhere near the
rate that the population of memes is growing. There is competition
for the limited space in human brains for memes, and something
has to give. Thanks to our incessant and often technically
brilliant efforts, and our apparently insatiable appetites
for novelty, we have created an explosively growing flood
of information, in all media, on all topics, in every genre.
Now either (1) we will drown in this flood of information,
or (2) we won't drown in it. Both alternatives are deeply
disturbing. What do I mean by drowning? I mean that we will
become psychologically overwhelmed, unable to cope, victimized
by the glut and unable to make life-enhancing decisions in
the face of an unimaginable surfeit. (I recall the brilliant
scene in the film of Evelyn Waugh's dark comedy The Loved
One in which embalmer Mr. Joyboy's gluttonous mother
is found sprawled on the kitchen floor, helplessly wallowing
in the bounty that has spilled from a capsized refrigerator.)
We will be lost in the maze, preyed upon by whatever clever
forces find ways of pumping money–or simply further
memetic replications–out of our situation. (In The
War of the Worlds, H. G. Wells sees that it might well
be our germs, not our high-tech military contraptions, that
subdue our alien invaders. Similarly, might our own minds
succumb not to the devious manipulations of evil brainwashers
and propagandists, but to nothing more than a swarm of irresistible
ditties, Noφs nibbled to death by slogans and one-liners?)
we don't drown, how will we cope? If we somehow learn
to swim in the rising tide of the infosphere, that will entail
that we–that is to say, our grandchildren and their
grandchildren–become very very different from our recent
ancestors. What will "we" be like? (Some
years ago, Doug Hofstadter wrote a wonderful piece, " In
2093, Just Who Will Be We?" in which he imagines robots
being created to have "human" values, robots that
gradually take over the social roles of our biological descendants,
who become stupider and less concerned with the things we value.
If we could secure the welfare of just one of these groups,
our children or our brainchildren, which group would we care
about the most, with which group would we identify?)
Whether "we" are
mammals or robots in the not so distant future, what will
we know and what will we have forgotten forever, as our previously
shared intentional objects recede in the churning wake of
the great ship that floats on this sea and charges into the
future propelled by jets of newly packaged information? What
will happen to our cultural landmarks? Presumably our
descendants will all still recognize a few reference points
(the pyramids of Egypt, arithmetic, the Bible, Paris, Shakespeare,
Einstein, Bach . . . ) but as wave after wave of novelty
passes over them, what will they lose sight of? The
Beatles are truly wonderful, but if their cultural immortality
is to be purchased by the loss of such minor 20th century
figures as Billie Holiday, Igor Stravinsky, and Georges Brassens
[who he?], what will remain of our shared understanding?
intergenerational mismatches that we all experience in macroscopic
versions (great-grandpa's joke falls on deaf ears, because
nobody else in the room knows that Nixon's wife was named "Pat")
will presumably be multiplied to the point where much of
the raw information that we have piled in our digital storehouses
is simply incomprehensible to everyone–except that
we will have created phalanxes of "smart" Rosetta-stones
of one sort or another that can "translate" the
alien material into something we (think maybe we) understand.
I suspect we hugely underestimate the importance (to our
sense of cognitive security) of our regular participation
in the four-dimensional human fabric of mutual understanding,
with its reassuring moments of shared–and seen to
be shared, and seen to be seen to be shared–comprehension.
will happen to common knowledge in the future? I
do think our ancestors had it easy: aside from all the juicy
bits of unshared gossip and some proprietary trade secrets
and the like, people all knew pretty much the same things,
and knew that they knew the same things. There just wasn't
that much to know. Won't people be able to create and
exploit illusions of common knowledge in the future,
virtual worlds in which people only think they are in touch
with their cyber-neighbors?
see small-scale projects that might protect us to some degree,
if they are done wisely. Think of all the work published
in academic journals before, say, 1990 that is in danger
of becoming practically invisible to later researchers because
it can't be found on-line with a good search engine. Just
scanning it all and hence making it "available" is
not the solution. There is too much of it. But we could start
projects in which (virtual) communities of retired researchers
who still have their wits about them and who know particular
literatures well could brainstorm amongst themselves, using
their pooled experience to elevate the forgotten gems, rendering
them accessible to the next generation of researchers. This
sort of activity has in the past been seen to be a stodgy
sort of scholarship, fine for classicists and historians,
but not fit work for cutting-edge scientists and the like.
I think we should try to shift this imagery and help people
recognize the importance of providing for each other this
sort of pathfinding through the forests of information. It's
a drop in the bucket, but perhaps if we all start thinking
about conservation of valuable mind-space, we can save ourselves
(our descendants) from informational collapse.
Psychologist, Harvard University
idea that ideas can be dangerous
does not mean exciting or bold. It means likely to cause
great harm. The most dangerous idea is the only dangerous
idea: The idea that ideas can be dangerous.
live in a world in which people are beheaded, imprisoned,
demoted, and censured simply because they have opened their
mouths, flapped their lips, and vibrated some air. Yes, those
vibrations can make us feel sad or stupid or alienated. Tough
shit. That's the price of admission to the marketplace of
ideas. Hateful, blasphemous, prejudiced, vulgar, rude, or
ignorant remarks are the music of a free society, and the
relentless patter of idiots is how we know we're in one.
When all the words in our public conversation are fair, good,
and true, it's time to make a run for the fence.
School of Philosophy, Psychology and Language Sciences, Edinburgh
quick-thinking zombies inside us
much of what we do, feel, think and choose is determined
by non-conscious, automatic uptake of cues and information.
Of course, advertisers will say they have known this all along.
But only in recent years, with seminal studies by Tanya Chartrand,
John Bargh and others has the true scale of our daily automatism
really begun to emerge. Such studies show that it is possible
(it is relatively easy) to activate racist stereotypes that
impact our subsequent behavioral interactions, for example
yielding the judgment that your partner in a subsequent game
or task is more hostile than would be judged by an unprimed
control. Such effects occur despite a subject's total and honest
disavowal of those very stereotypes. In similar ways it is
possible to unconsciously prime us to feel older (and then
we walk more slowly).
my favorite recent study, experimenters manipulate cues so
that the subject forms an unconscious goal, whose (unnoticed)
frustration makes them lose confidence and perform worse
at a subsequent task! The dangerous truth, it seems to me,
is that these are not isolated little laboratory events.
Instead, they reveal the massed woven fabric of our day-to-day
existence. The underlying mechanisms at work impart an automatic
drive towards the automation of all manner of choices and
actions, and don't discriminate between the 'trivial' and
now seems clear that many of my major life and work decisions
are made very rapidly, often on the basis of ecologically
sound but superficial cues, with slow deliberative reason
busily engaged in justifying what the quick-thinking zombies
inside me have already laid on the table. The good news is
that without these mechanisms we'd be unable to engage in
fluid daily life or reason at all, and that very often they
are right. The dangerous truth, though, is that we are indeed
designed to cut conscious, aware choice out of the picture
wherever possible. This is not an issue about free will,
but simply about the extent to which conscious deliberation
cranks the engine of behavior. Crank it it does: but not
in anything like the way, or extent, we may have thought.
We'd better get to grips with this before someone else does.
Author, Life on the Screen: Identity in the Age of the
several generations of living in the computer culture,
simulation will become fully naturalized. Authenticity
in the traditional sense loses its value, a vestige of
this moment from 2005: I take my fourteen-year-old daughter
to the Darwin exhibit at the American Museum of Natural History.
The exhibit documents Darwin's life and thought, and with
a somewhat defensive tone (in light of current challenges
to evolution by proponents of intelligent design), presents
the theory of evolution as the central truth that underpins
contemporary biology. The Darwin exhibit wants to convince
and it wants to please. At the entrance to the exhibit is
a turtle from the Galapagos Islands, a seminal object in
the development of evolutionary theory. The turtle rests
in its cage, utterly still. "They could have used a
robot," comments my daughter. It was a shame to bring
the turtle all this way and put it in a cage for a performance
that draws so little on the turtle's "aliveness." I
am startled by her comments, both solicitous of the imprisoned
turtle because it is alive and unconcerned by its authenticity.
The museum has been advertising these turtles as wonders,
— among the plastic models of life at the museum, here
is the life that Darwin saw. I begin to talk with others at
the exhibit, parents and children. It is Thanksgiving weekend.
The line is long, the crowd frozen in place. My question, "Do
you care that the turtle is alive?" is welcome diversion.
A ten year old girl would prefer a robot turtle because aliveness
comes with aesthetic inconvenience: "It's water looks
dirty. Gross." More usually, the votes for the robots
echo my daughter's sentiment that in this setting, aliveness
doesn't seem worth the trouble. A twelve-year-old girl opines: "For
what the turtles do, you didn't have to have the live ones." Her
father looks at her, uncomprehending: "But the point is
that they are real, that's the whole point."
Darwin exhibit is about authenticity: on display are the
actual magnifying glass that Darwin used, the actual notebooks
in which he recorded his observations, indeed, the very notebook
in which he wrote the famous sentences that first described
his theory of evolution But in the children's reactions to
the inert but alive Galapagos turtle, the idea of the "original" is
have long believed that in the culture of simulation, the
notion of authenticity is for us what sex was to the Victorians — "threat
and obsession, taboo and fascination." I have lived
with this idea for many years, yet at the museum, I find
the children's position startling, strangely unsettling.
For these children, in this context, aliveness seems to have
no intrinsic value. Rather, it is useful only if needed for
a specific purpose. "If you put in a robot instead of
the live turtle, do you think people should be told that
the turtle is not alive?" I ask. Not really, say several
of the children. Data on "aliveness" can be shared
on a "need to know" basis, for a purpose. But what are the
purposes of living things? When do we need to know if something
another vignette from 2005: an elderly woman in a nursing
home outside of Boston is sad. Her son has broken off his
relationship with her. Her nursing home is part of a study
I am conducting on robotics for the elderly. I am recording
her reactions as she sits with the robot Paro, a seal-like
creature, advertised as the first "therapeutic robot" for
its ostensibly positive effects on the ill, the elderly,
and the emotionally troubled. Paro is able to make eye contact
through sensing the direction of a human voice, is sensitive
to touch, and has "states of mind" that are affected
by how it is treated, for example, is it stroked gently or
with agressivity? In this session with Paro, the woman, depressed
because of her son's abandonment, comes to believe that the
robot is depressed as well. She turns to Paro, strokes him
and says: "Yes, you're sad, aren't you. It's tough out
there. Yes, it's hard." And then she pets the robot
once again, attempting to provide it with comfort. And in
so doing, she tries to comfort herself.
woman's sense of being understood is based on the ability
of computational objects like Paro to convince their users
that they are in a relationship. I call these creatures (some
virtual, some physical robots) "relational artifacts." Their
ability to inspire relationship is not based on their intelligence
or consciousness, but on their ability to push certain "Darwinian" buttons
in people (making eye contact, for example) that make people
respond as though they were in relationship. For
me, relational artifacts are the new uncanny in our computer
culture — as Freud once put it, the long familiar taking
a form that is strangely unfamiliar. As such, they confront
us with new questions.
does this deployment of "nurturing technology" at
the two most dependent moments of the life cycle say about
us? What will it do to us? Do plans to provide relational
robots to attend to children and the elderly make us less
likely to look for other solutions for their care? People
come to feel love for their robots, but if our experience
with relational artifacts is based on a fundamentally deceitful
interchange, can it be good for us? Or might it be good for
us in the "feel good" sense, but bad for us in
our lives as moral beings?
with robots bring us back to Darwin and his dangerous
idea: the challenge to human uniqueness. When we see children
and the elderly exchanging tendernesses with robotic pets
the most important question is not whether children will
love their robotic pets more than their real life pets or
even their parents, but rather, what will loving come to
Applied mathematician, Cornell University; Author, Sync
End of Insight
worry that insight is becoming impossible, at least at the
frontiers of mathematics. Even when we're able to figure
out what's true or false, we're less and less able to understand
argument along these lines was recently given by Brian Davies
in the "Notices of the American Mathematical Society".
He mentions, for example, that the four-color map theorem
in topology was proven in 1976 with the help of computers,
which exhaustively checked a huge but finite number of possibilities.
No human mathematician could ever verify all the intermediate
steps in this brutal proof, and even if someone claimed to,
should we trust them? To this day, no one has come up with
a more elegant, insightful proof. So we're left in the unsettling
position of knowing that the four-color theorem is true but
still not knowing why.
important but unsatisfying proofs have appeared in group
theory (in the classification of finite simple groups, roughly
akin to the periodic table for chemical elements) and in
geometry (in the problem of how to pack spheres so that they
fill space most efficiently, a puzzle that goes back to Kepler
in the 1500's and that arises today in coding theory for
my own field of complex systems theory, Stephen Wolfram has
emphasized that there are simple computer programs, known
as cellular automata, whose dynamics can be so inscrutable
that there's no way to predict how they'll behave; the best
you can do is simulate them on the computer, sit back, and
watch how they unfold. Observation replaces insight. Mathematics
becomes a spectator sport.
this is happening in mathematics, the supposed pinnacle of
human reasoning, it seems likely to afflict us in science
too, first in physics and later in biology and the social
sciences (where we're not even sure what's true, let alone
the End of Insight comes, the nature of explanation in science
will change forever. We'll be stuck in an age of authoritarianism,
except it'll no longer be coming from politics or religious
dogma, but from science itself.
Computational Neuroscientist, Howard Hughes Medical
Institute; Coauthor, The Computational Brain
will the Internet become aware of itself?
never thought that I would become omniscient during my lifetime,
but as Google continues to improve and online information
continues to expand I have achieved omniscience for all practical
purposes. The Internet has created a global marketplace for
ideas and products, making it possible for individuals in
the far corners of the world to automatically connect directly
to each other. The Internet has achieved these capabilities
by growing exponentially in total communications bandwidth.
How does the communications power of the Internet compare
with that of the cerebral cortex, the most interconnected
part of our brains?
connections are expensive because they take up volume and
cost energy to send information in the form of spikes along
axons. About 44% of the cortical volume in humans is taken
up with long-range connections, called the white matter.
Interestingly, the thickness of gray matter, just a few millimeters,
is nearly constant in mammals that range in brain volume
over five orders of magnitude, and the volume of the white
matter scales approximately as the 4/3 power of the volume
of the gray matter. The larger the brain, the larger the
fraction of resources devoted to communications compared
the global connectivity in the cerebral cortex is extremely
sparse: The probability of any two cortical neurons having
a direct connection is around one in a hundred for neurons
in a vertical column 1 mm in diameter, but only one in a
million for more distant neurons. Thus, only a small
fraction of the computation that occurs locally can be reported
to other areas, through a small fraction of the cells that
connect distant cortical areas.
the sparseness of cortical connectivity, the potential bandwidth
of all of the neurons in the human cortex is approximately
a terabit per second, comparable to the total world backbone
capacity of the Internet. However, this capacity is never
achieved by the brain in practice because only a fraction
of cortical neurons have a high rate of firing at any given
time. Recent work by Simon Laughlin suggests that another
physical constraint — energy — limits the brain's
ability to harness its potential bandwidth.
cerebral cortex also has a massive amount of memory. There
are approximately one billion synapses between neurons under
every square millimeter of cortex, or about one hundred million
million synapses overall. Assuming around a byte of storage
capacity at each synapse (including dynamic as well as static
properties), this comes to a total of 1015 bits
This is comparable to the amount of data on the entire Internet;
Google can store this in terabyte disk arrays and has hundreds
of thousands of computers simultaneously sifting through
the internet and our ability to search it are within reach
of the limits of the raw storage and communications capacity
of the human brain, and should exceed it by 2015.
van Hemmen and I recently asked 23 neuroscientists to think
about what we don't yet know about the brain, and to propose
a question so fundamental and so difficult that it could
take a century to solve, following in the tradition of Hilbert's
23 problems in mathematics. Christof Koch and Francis Crick
speculated that the key to understanding consciousness was
global communication: How do neurons in the diverse
parts of the brain manage to coordinate despite the limited
connectivity? Sometimes, the communication gets crossed,
and V. S. Ramachandran and Edward Hubbard asked whether synesthetes,
rare individuals who experience crossover in sensory perception
such as hearing colors, seeing sounds, and tasting tactile
sensations, might give us clues to how the brain evolved.
is growing evidence that the flow of information between
parts of the cortex is regulated by the degree of synchrony
of the spikes within populations of cells that represent
perceptual states. Robert Desimone and his colleagues have
examined the effects of attention on cortical neurons in
awake, behaving monkeys and found the coherence between the
spikes of single neurons in the visual cortex and local field
potentials in the gamma band, 30-80 Hz, increased when the
covert attention of a monkey was directed toward a stimulus
in the receptive field of the neuron. The coherence also
selectively increased when a monkey searched for a target
with a cued color or shape amidst a large number of distracters.
The increase in coherence means that neurons representing
the stimuli with the cued feature would have greater impact
on target neurons, making them more salient.
link between attention and spike-field coherence raises a
number of interesting questions. How does top-down input
from the prefrontal cortex regulate the coherence of neurons
in other parts of the cortex through feedback connections?
How is the rapidity of the shifts in coherence achieved? Experiments
on neurons in cortical slices suggest that inhibitory interneurons
are connected to each other in networks and are responsible
for gamma oscillations. Researchers in my laboratory have
used computational models to show that excitatory inputs
can rapidly synchronize a subset of the inhibitory neurons
that are in competition with other inhibitory networks. Inhibitory
neurons, long thought to merely block activity, are highly
effective in synchronizing neurons in a local column already
firing in response to a stimulus.
oscillatory activity that is thought to synchronize neurons
in different parts of the cortex occurs in brief bursts,
typically lasting for only a few hundred milliseconds. Thus,
it is possible that there is a packet structure for long-distance
communication in the cortex, similar to the packets that
are used to communicate on the Internet, though with quite
different protocols. The first electrical signals recorded
from the brain in 1875 by Richard Caton were oscillatory
signals that changed in amplitude and frequency with the
state of alertness. The function of these oscillations remains
a mystery, but it would be remarkable if it were to be discovered
that these signals held the secrets to the brain's global
its inception in 1969, the Internet has been scaled up to
a size not even imagined by its inventors, in contrast to
most engineered systems, which fall apart when they are pushed
beyond their design limits. In part, the Internet achieves
this scalability because it has the ability to regulate itself,
deciding on the best routes to send packets depending on
traffic conditions. Like the brain, the Internet has circadian
rhythms that follow the sun as the planet rotates under it.
The growth of the Internet over the last several decades
more closely resembles biological evolution than engineering.
would we know if the Internet were to become aware of itself? The
problem is that we don't even know if some of our fellow
creatures on this planet are self aware. For all we know
the Internet is already aware of itself.