Miracle of Consciousness
The understanding of cognition is very much a work-in-progress. I'm not
an expert but I will try to communicate some results that are
philosophically satisfying and useful in situations we encounter every
day. They help to clarify the meaning of concepts like
"understanding" and "awareness" and to dispel the mystery that leads to
magical thinking and supernatural mythology. And they help us to
appreciate the miraculous character of our everyday experience.
Consciousness is - A dynamic, creative, open-ended process to build an
internal representation of reality, that seems to be stable but
is actually made up of many dynamic processes.
We use sensory input, pattern recognition, fill-in-the-blanks from
memory of past experience, and extrapolation from knowing unseen parts
of objects and knowing what to expect from our surroundings and from
our own efforts.
In retrospect, a few leading lights have shown clarity, for
example, William James, about 1890, wrote "Consciousness is a
process, not a thing."
Is the time you get up in the morning a thing? No, that's sloppy
thing-king! Any-thing we can name must be a thing? No - We
can name ideas and processes! And - they exist, but in a very
different way from things!
In this decade the tools have finally become available to dig out the
details of brain functions. Functional MRI (Magnetic Resonance
Imaging) and PET (Proton Emission Tomography) can localize the
neurological activity associated with brain functions that are called
forth in psychological or pharmacological experiments. In past
years that information was only available by chance, from studying
patients with localized brain damage. And the detailed functions
of individual nerve cells could only be explored by micro-manipulation
of electrodes during radical surgery of experimental animals or lower
life forms. Now new results are reported every day.
And we now have the logical and philosophical sophistication that comes
from our experience of programming electronic computers to do complex
The computer, so far, is a tool that depends on the precise execution
of stored instructions, at great speed, with no originality. For
example, a GPS receiver like you might have in your car, can calculate
from the timing of satellite signals, its location anywhere on earth,
and display a map showing your position. It uses a mathematical
model of the satellite orbits and radio propagation. And we can
model the motions of our atmosphere and calculate tomorrow's weather
from today's observations but the task is so extensive that it takes
many computers operating in parallel, on localized bits of the problem,
to be of any use.
Our brain is a massively parallel computer system that models our
reality. In fact all our bodily processes are self-motivated
parallel systems which function as they must and we are aware of them
only when they need our attention.
When we catch a fly ball in a baseball game we are modeling the physics
of gravity and air resistance to judge where we must be when it comes
down. But we don't use numbers and mathematical equations to do
it. We use our visual and kinesthetic senses and our remembered
past experience to elicit the muscular effort to adjust our position
So how do we do that?
Our Central Nervous System, including the spinal cord, brainstem,
cerebral hemispheres, optic nerves, and retina of the eyes, contains
about 100,000 million neurons. These are cells specialized for
signaling, and they each connect with about 1000 other neurons.
They function in parallel, each working at its own pace, so we can't
possibly be aware of all that they do.
Neurons have a cell body, which contains the nucleus and where most of
the cell's metabolic functions are located, and input fibers called
dendrites, and an axon, a long fiber where the all-or-nothing output
signal is conveyed to other neurons or to muscle cells that contract
when stimulated. The connection to another neuron or muscle cell
is called a synapse, a microscopic button that is specialized to
release chemicals called neurotransmitters which either stimulate or
inhibit the cell they connect with. Both axons and dendrites may
extend for some distance and may be branched to connect with many other
Every neuron is a little decision-maker. The cell membrane acts
like a chemical battery, maintaining a several-millivolt potential
difference between inside and outside. When the neuron is
stimulated, by an appropriate combination of input signals, a process
occurs that allows potassium ions and sodium ions to penetrate the
membrane, which is like short-circuiting the battery. This
produces an impulse of millivolts, that lasts several milliseconds,
which propagates along the nerve fiber at hundreds of feet per
second. Then the system recovers to repeat a few hundred times a
After early childhood nerve cells ordinarily do not reproduce, but the
synapses are reinforced or attenuated depending on their
activity. By this means clusters of nerve cells become
specialized according to the inputs they receive, from sensory organs,
from surrounding or distant neurons, and from positive or negative
feedback from near and far in the brain. Thus they are constantly
combing their connections for combinations that are significant, and
reinforcing those that turn out to be useful.
So we, and other animals, have evolved the associative capability for
pattern recognition, which becomes the basis for memory because related
inputs can restimulate patterns from previous expenence.
This pattern recognition process starts in the sensory organs.
For example the retina of the eye contains the rod and cone cells which
are stimulated when light quanta are absorbed by the photopigments they
contain, and also associative neurons that connect with various
combinations of surrounding cells. The million axons that go to
the brain through the optic nerve are triggered by various combinations
of contrast in the optical image projected by the lens from the outside
world. They represent edges and orientations and motions and
color contrasts in the visual image, and they are routed to different
areas of the cerebral cortex to be recognized as features of the visual
The process of constructing a visual scene in our brain from these
inputs is quite sophisticated using elements from the areas that
process the abstracted optic nerve signals and relying on automatic eye
motions to fill in blanks in the retinal image. In fact blood
vessels in the eye pass in front of the retina, and there is a large
blind spot where the optic nerve exits. And the color-sensitive
cone cells are crowded only in a small area called the fovea, where we
see with high resolution.
Thus our brain incorporates a built-in system for working around the
deficits in our vision and presenting a picture of reality that seems
stable in spite of eye movement, with resolution everywhere as good as
fovial vision. We can always fill in the blanks by glancing in
another direction so it's OK to think that our vision is better than it
So with layer upon layer of simple pattern recognition elements we
create an "imagined present" incorporating object/background
discrimination and using motion and binocular parallax to give depth
perception and incorporating what we know from past experience of
Similar abstraction and reconstruction occurs with the other senses -
we need motion to sense touch and body position, and we sense pitch
intervals of tones better than absolute pitch.
And so - to our associative pattern-recognition system an object is
like a song. A few familiar notes remind us of a whole definitive
performance. And from recognizing a few features of an object we
imagine the whole thing, in its generic form that fits the features in
And the most vital senses are those that change with time - moving
objects or sound patterns, or our own bodily motions. We can
extrapolate, from our remembered experience and sensory inputs, and
imagine where that fly ball will come down and how to propel ourselves
to be there to catch it. Imagination is modeling, of real or potential
events, which is easy with the massively parallel pattern- recognition
elements of our cerebral cortex, and awkward with the serial execution
of sequential program steps in a digital computer.
Thus our perception of our present situation is a dynamic, creative
process - using the scientific method - where we construct a hypothesis
about what's happening and compare with developing reality. We
fill in the blanks by glancing where we need-to-know and revise our
estimate, forgetting whatever was wrong in our world-view. So we
are only aware of the result and the pattern-recognition processes are
unconscious, self-propelled parallel processing by the billions of
living neurons, each doing its own thing.
With that introduction we can now look at some details of what's known
about the working brain. I'll try to fill in some broad outlines
without getting lost in detail.
Humans are the result of biological evolution along with the many life
forms on Earth today and in the past. We share the basic
biochemical functions of cellular existence with bacteria and with most
other life forms. We share the basic functioning of our nervous
system with the chordates, that include some microscopic worm species,
fish, and amphibians, reptiles, birds, and mammals of today.
But we have evolved a particular part of our brain, called the
neocortex from its recent evolution, way larger than any other animal.
This cortex is the "grey matter" which is the
about-two-millimeters-thick outer layer or rind of the large
hemispheres that surround the midbrain anatomy at the top of the spinal
cord. It has about the area of a large dinner napkin but it is crumpled
to fit inside the skull. The major folds divide the lobes of the
brain - frontal, temporal, occipital, parietal - and the left and right
hemispheres are separate except for a bridge of fibers called the
corpus callosum, and two small commisures.
Microscopic examination of the cortex shows several varieties of
neurons, with the outer layer consisting mainly of axon and dendrite
fibers that communicate with other neurons near and far. The
inner layer is devoted to sending and receiving signals to and from the
The "white matter" beneath the cortex is a solid mass of myelinated
nerve fibers that connect to the midbrain structures that evolved long
before the neocortex. These structures appear to be involved in
sleep and arousal, and in regulating the activity of the cortex but not
in the actual pattern recognition. They play a critical part in the
control of other functions, like attention, emotion, mood, motivation,
and movement. The reticular formation in the midbrain stimulates the
motor cortex to produce the state of wakefulness called
"consciousness". Damage here can produce a coma, or deep
The connecting fibers go both ways and provide value-judgement feedback
to control attention and long-term memory. Those details are
being explored with functional imaging experiments but they are outside
the range of this presentation. (Show Science Magazine 18 Feb 05)
To explain feedback we need to jump back to electrical
engineering. In the 1930's vacuum tube amplifiers were used to
amplify audio signals from microphone or phonograph pickup, to drive a
loudspeaker to reproduce the sound. But the sound was distorted
because the output current was not exactly proportional to the input
voltage waveform. In the 1940's this was corrected by using
"negative feedback". The input signal was compared to a sample of
the output, and the amplifier was driven by the difference. With
a high-gain amplifier the output was driven to make the difference very
close to zero, so the output was made accurately proportional to the
input in spite of distortion in the amplifier. This design
feature has been standard practice ever since, and we now recognize it
when we see it in natural systems.
You may be familiar with feedback in another context. The internet
auction program E-Bay asks both buyer and seller for feedback after a
transaction and it accumulates a composite rating for both
participants, over their whole history of participation. These ratings
are publicly available to facilitate improved judgement about
reliability of anonymous trading partners.
And we use feedback all the time. We watch what we are doing and adjust
our muscular effort to do what we want to do. Our mental image of
the motion is compared with reality and we minimize the
difference. "Wishing will make it so!"
The dynamic selection in our cerebral cortex of patterns that are
significant, and the hierarchical selection of patterns of patterns of
patterns that are related, is a feedback process that facilitates a
richness of memory and imagination that is so massive that we can only
use a bit of it at a time.
So our awareness is a stream-of-consciousness, one-thing-at-a-time,
concentration of attention that leaves most of our mental faculties
out-of-sight. But they are there, available as needed.
Doing a crossword puzzle is an example of associative memory
performance that is unconscious. It's a miracle that words which
fit appear in our mind without rational, sequential, "reasonable"
thought! In fact we must consciously clear our mind of rational
thought to succeed.
So - The human animal has evolved with a mental capacity that has made
us masters of the world, whether we want to or not. The
breakthrough achievement that makes us "better" than all the other
animals is language capability. The survival value of
communication has enabled the rapid evolution, in under 100,000 years,
of our capability to mold the environment to our needs and to
overpopulate the Earth.
Another digression into the technology of communication - In the 1930's
telephone and radio engineers were recognizing the relation of data
rate to bandwidth. A unit of data was defined, the binary digit,
or "bit". It was understood that a radio channel needs a ten
kilocycle-per-second bandwidth and a television channel needs a ten
megacycle-per-second bandwidth, about 1000 times as much. Why? Because
a sound wave is a single sequence of air pressure changes which can be
communicated by a serial presentation of data. Projecting or viewing a
picture requires the simultaneous or parallel transmission of
brightness values for every point in the image. The television
camera is a parallel-to-serial data converter because it scans and
transmits every point in the image sequentially, thirty times a second.
Incidentally, much of that data is redundant, because consecutive
frames have pictures that are almost alike. Contemporary digital
television economizes by transmitting only the differences of each
image from the one before. Remember the optic nerve? Each fiber
responds to differences of light intensity on nearby sensitive cells,
representing features of the visual scene. This is a data
compression technique, transmitting only what's important for the brain
to make its reconstruction.
Our use of language involves much more than the ability to give meaning
to symbols as is popularly supposed. It requires the rapid
retrieval from memory of a series of sound patterns and the capability
to express them with our vocal anatomy. But more than that, it
requires choosing, from a multitude of possibilities, the ideas we want
to communicate and the words to express them in the grammatical
arrangement that a listener can understand. In the computer world
this is called parallel-to-serial conversion. And the listener
does a serial-to-parallel conversion to interpret the sound sequence as
words, with meanings that depend on context, retrieved from among many
possible interpretations. And if it's a new idea the listener will
store it in an associative memory that links it to other related ideas
for easy recall.
For example the same words might have very different meanings.
Remember a song that ends: "And nothing will stop the Army Air
Corps!" Does that mean that they can be stopped by nothing?
No, just the opposite, but our language is full of ambiguities that we
never notice because our sophisticated language faculty interprets in
It's amazing that a single-channel medium of communication, with only a
few syllables-per-second data rate, can be so expressive. Credit
the massively-parallel pattern recognition machine that is our cerebral
Incidental to the survival value of language for communication, the
necessary mental sophistication brought other benefits. We had to be
more explicitly aware of our own thoughts to explain them to others,
and we had to be self-conscious in a new way. We had to see
ourselves as others see us, in order to express ourselves so they could
understand. And we could develop a culture of common knowledge
that was more reliable because it was tested and revised by many
people. The scientific method could become an explicit cultural
artifact, as well as an unconscious part of our everyday awareness.
But now our "awareness" of rational thought is cast in the mold of
verbal communication, explaining ourselves to others. We think of
"understanding" as a step-by-step, cause-and-effect explanation.
We don't give credit to the unconscious part of our mental processes,
the intuition and imagination and the creativity. We need to
rationalize everything we do because we don't trust ourselves unless we
can offer a verbal explanation. So our awareness of knowledge is
framed that way.
So - if all we know is what we think, then of course we think we know
The creation of new connections - new awareness, new ideas, new
possibilities, is the miraculous result of the massively parallel
pattern recognition machine, that we have always lived with and taken
for granted. So - the creation of new thoughts that represent
something in reality - actual or potential - is such a familiar
experience that it is easy to believe in miracles in the real world.
But we don't need the mythology, except to treasure the subtlety of our
heritage. We should take credit for our own creations.
I'm reminded of a song from a 1939 movie, a favorite of my third-grade
teacher, that I thought at the time was unrealistic nonsense. But
now I realize that it expresses the experience that is part of
everything we do, the feeling of motivation that is part of the
self-regulating system we use to guide our efforts to accomplish
whatever we want, from bodily motions to acts of creation.
Wishing will make it so!
From Love Affair (De Silva 1939)
Wishing will make it so.
Just keep on wishing and cares will go.
Dreamers tell us dreams come true, it’s no mistake.
And wishes are the dreams we dream when we’re awake.
The curtain of night will part, if you are certain within your heart.
So if you wish long enough, wish strong enough, you will come to know
Wishing will make it so.