dwarren@ssc-vax.UUCP (David Warren) (04/22/89)
AI ANSWERS
by Arthur T. Murray
Mentifex Systems
Post Office Box 31326
Seattle, Washington 981
03-1326 USA
Once we know all there is to know about the workings of the human brain,
we will have a choice of several obvious approaches to the task of teaching
students the essential workings of the mind. We could teach about the
brain-mind in terms of how it evolved through the eons, or how it develops in
the life of the individual, or how it functions in a mature specimen.
This article presents the author's model of the workings of the
brain-mind, not in terms of sweeping generalizations but
on the ultimate and unambiguous level of the switching-circuit logic of nerve
cells. You are invited to comprehend this mind-model - to refute it if it is
erroneous, or, if it makes sense to you, to use it in fulfilling the ancient
imperative,"Know thyself!" Either way, you the sovereign mind are offered
something to react against, and possibly a revelation of your inmost mental
nature.
Of three obvious approaches to explaining the mind inside the brain -
evolution, individual development, and static functioning in maturity - this
author chooses the third route and seeks to describe your mature mind as you
read and comprehend this article.
The other two approaches - evolution of the mind in the species,
development of mind in the specimen - would inherently contain directions for
the starting-place and the order of presentation of all essential details
about the brain-mind. In both cases, we would simply describe how a
single-cell creature turned into a brain of one hundred billion cells.
But let's take the hundred billion cells and find an obvious point of
departure for describing a model of the organization and fu
nction of thatpurposive web of cells, the brain. Let us approach the function
of the evolved, mature mind from the obvious starting-point of sensory inputs
intothe mind.
This article leads you through a functional model of the brain-mind.
Although the brain is perhaps the most complex structure on earth, it is no
more than a three-dimensional arrangement of flows of information. The
information-flows are arranged in such a way as to achieve consciousness and
thought.
Each flow of information is along one of the dimensions of the mind. If
you are to comprehend this mind-model, you must understand each dimension and
also the very concept of dimensionality. The dimensions play a double role
in this article: firstly as the building-blocks of the mind for you to
comprehend both one by one and as a grand edifice, and secondly as the chief
arguments to convince you of the validity of the mind-model.
Dimensionality is the quality of being dimensional, of having
dimensions. The mind is not a seething lump like an anthill, but a strictly
dimensional structure. Although the brain is curved and convoluted, the mind
inside the brain is rigidly straight (like a taut string or a beam of light)
in all its dimensions, and orthogonal through ninety degrees wherever the
information in one dimension changes its direction of flow into another
dimension.
Although the mind exists within the brain, the mind is not a material,
physical being. The mind is a structure composed purely of information. The
physical structure of the brain determines the informational structure of the
mind, but these two structures are not identical. Put it this way: The
brain holds information, and information holds the mind. The brain is
organized physically, but the mind is organized logically.
The dimensionality of the mind is crucial to its logical structure. In
some parts of the mind, information must be kept apart, while in other parts
of the mind information must flow together. The dimensions of the mind serve
the purposes of isolating and combining information.
The first dimensional component of your mind is the straight and linear
record of its sensory input, in parallel with the straight and linear
"keyboard" of its motor output. Please examine the "mind-diagram" appearing
with this article.
A polarity exists between the mind and its environment. An environment
to develop in is just as essential to the mind as a brain to exist in.
A second polarity exists between our sensory perception of the
environment and our motor manipulation of the environment.
These two polarities - organism/environment and sensory/motor -
constitute sufficient logical differentiation for the genesis of an
informational loop.
Your mind sits at one end of the loop and contemplates your environment
at the other end of the loop. Your environment is the whole cosmos,
including your body, brain, and mind. Your mind starts out as tabula rasa,
"a clean slate." As your mind develops and fills with knowledge, it tries to
mirror internally the cosmos which it perceives externally. Who can say
which is the agent - the cosmos organizing minds, or mind organizing the
cosmos?
Your mind starts out as an empty, but vastly capacious, link in the
loop. Information starts in the environment and flows in one direction
through the loop: through your senses into the mind, and from your mind out
through the motor nerves to the environment.
It takes a while for your neonatal pathways - sensory and motor - to
communicate internally and thus to close the loop with the environment. The
sensory and motor pathways develop in parallel along the temporal
dimensionof the mind.
Although your mind is constantly thinking and acting in the present, its
existence stretches off into the past. Every thought which you think in the
present, shapes your mind for the future. Your mind is the sum of all its
past reality.
It is critical to your comprehension of this mind-model that you think
of the sensory and motor pathways as flowing in parallel, but in opposite
directions, along the temporal dimension of the mind. When we go on now to
examine in detail the sensory-input system, you must keep in mind that the
sensory and motor systems develop and operate side by side in lock-step
fashion.
A human brain has the five commonly acknowledged senses of vision,
audition (hearing), the tactile sense (touch), gustation (taste), and
olfaction (smell), plus a few other senses such as the sense of balance and
the somesthetic sense.
According to this mind-model, all the senses feed into the mind in
parallel in a flat array like a woven rug. For each sense, be it vision or
audition or smelling the flowers, there is a flat channel of perception and
memory flowing along the time-dimension of the mind.
The nerves from the sense-receptors travel to the brain. Inside the
brain, the sensory information from vision, and perhaps other senses,
undergoes the pre-processing of feature-extraction before it enters the mind.
In feature-extraction, basic patterns are discriminated to reduce the
work-load and hasten the operation of the conscious mind. In the brain there
operates a principle of rendering automatic (and subconscious) as many things
as possible.
After the information in any one sensory pathway has reached the brain
and gone through all required feature-extraction, the information enters the
mind by entering the permanent memory channel for that particular sensory
modality. Short-term memory and permanent memory are identical in terms of
physical location, but they differ with respect to the associative processes
which catalog the memory-traces and control their future accessability
through recall. In other words, short-term memory is not a function of
location, but rather of associativity. This assertion is supported better by
the large-scale mind-model than by any local arguments which may appear in
this topical discussion of memory.
The distinction between preliminary portions of the brain and the mind
itself is based upon a functional demarcation line beyond which information
is free to flow not just along its original dimension but orthogonally
sideways out into other dimensions of the mind. In other words, the mind is
circumscribed and defined by its own dimensionality.
It is important that you now comprehend both a specific design for
memory and a general concept of memory. It is axiomatic that whatever
macroscopic information can be transmitted can also be recorded. To record
information during transmission, one simply captures samples of the
information at a rate quick enough to catch all instances of significant
change in the information.
The brain-mind records the informational content of each sensory channel
by routing the information through what is both a transmission channel and an
extremely long series of engram-nodes. Once each sensory information-flow
passes the demarcation-line into the mind, the information in each sensory
channel floods the transmission "fibers" of that permanent memory channel.
Each fiber in the memory channel is like a series of millions of nodes. Within
the particular memory channel for each sense, there are thousands of
the nodal fibers. Your oldest memories were deposited and permanently,
unchangeably fixed in the first nodes of the lifetime-long memory channels.
At each moment of sensation and perception, all the simultaneously occupied
nodes among all the the memory fibers of each memory channel irrevocably fix
their contents. The group of nodes fixed on parallel fibers at one moment in
time is like a "slice" of memory of that moment in time.
You start out with your sensory nerves and pathways going through any
required feature-extraction and then feeding into immensely long channels of
tabula rasa memory. Your myriad moments of experience are deposited in
densely packed "slices" of and by simultaneity.
Each sensory (and motor) memory channel is like a flat ribbon flowing
across the logical surface of the mind. The memory-ribbon is composed of
thousands of nodal fibers. The first experiences go into the first nodal
slices. Subsequent experiences have to travel through all the slice
s ofprevious experience to reach and occupy fresh nodal slices, which will then
be filled and fixed with the experience of the moment, before serving as a
bridge to all future moments.
Although it is critical for you to understand the essential
characteristics of the permanent memory channels in this mind-model, these
essential characteristics are not introduced here all at once. Advance
notice can be given, however, that each sensory memory channel serves three
main purposes, simultaneously and everywhere along the memory channel:
transmission, memory, and comparison.
Each sensory memory channel is like a pipeline full of nodal fibers.
The nodal fibers are already there, genetically provided and ready to
receive engrams of memory. The pipeline is gradually filling up with memory
slices all through your lifetime. The memory-slices are so densely packed
that you could live to be over a hundred years old and not run out of fresh,
unused, tabula rasa memory locations. The gradual fixation or consumption of
memory-slices is like a slow burning fuse, so long that it takes over a
hundred years to burn to the end. Even if you did run out of fresh
memory-spaces in your old age, you would still function as an intelligent
mind with full retention of your many decades of old memories and with the
loss of only your ability to remember each passing moment of the present.
You could still speak, for instance, several languages and do anything else
that you learned to do before your tabula rasa memory ran out.
This assertion is another one which ought to be judged in the light of the total
mind-model.
The flatness of each memory-channel matters to the brain, but not to the
mind. The serial order or arrangement of the nodal fibers does not matter at
all. Note that the information recorded in a flat slice of memory is
certainly not "flat" information. The flat memory channel for the tactile
sense of touch contains a sensory mapping of the whole surface of the body.
The flat auditory memory channel contains a mapping of a broad range of
frequencies of sound. The flat visual memory channel contains two-dimensional
images in a one-dimensional series of fiber-nodes. The mind does not know and
does not care that the images are flat. When the mind associatively recalls an
image-slice, the one-dimensional memory-slice springs to life as if it were
the two-dimensional image seen through the eye.
We are really getting into the dimensionality of the mind when we bring
in the idea of associativity. Sensory information flows into the mind along
the time-dimension, but it moves sideways within the mind along the associative
dimension. Every sensory memory slice is attached to a "concrete
associative tag" that is like a fiber flowing at a right angle to all the
fibers in the flat memory channels of the time-dimension. These concrete
associative tag-fibers are not shown in the mind-diagram, because they would
completely black out the mind portion of the diagram. They are called
"concrete" (as opposed to "abstract") because they coordinate by simultaneity
all the sensory memory-slices of "concrete" experience. They are called
"associative" because they are the mechanism by which the mind associates a
memory-slice in one sensory modality with memory-slices in all other sensory
modalities and even in the same sensory modality. For instance, they are the
mechanism by which you might associate the sound with the image of a dog, and
vice versa.sarima@gryphon.COM (Stan Friesen) (04/30/89)
In article<1261@ssc-bee.ssc-vax.UUCP>dwarren@ssc-vax.UUCP (David Warren) writes: > Although the mind exists within the brain, the mind is not a material, >physical being. The mind is a structure composed purely of information. The >physical structure of the brain determines the informational structure of the >mind, but these two structures are not identical. Put it this way: The >brain holds information, and information holds the mind. The brain is >organized physically, but the mind is organized logically. In general I find tend to find this a reasonable view of the mind. However, I have a small nit to pick here. I would not use the term "logical" for the organization of the mind, unless you mean something other than Aristotilean logic. I would rather say that the mind is organized "topically" or "experientially" or "subjectively". > Your mind sits at one end of the loop and contemplates your environment >at the other end of the loop. Your environment is the whole cosmos, >including your body, brain, and mind. Your mind starts out as tabula rasa, >"a clean slate." As your mind develops and fills with knowledge, it tries to >mirror internally the cosmos which it perceives externally. Who can say >which is the agent - the cosmos organizing minds, or mind organizing the >cosmos? Another nit, I think that this is rather an oversimplification. There is considerable evidence for at least some "pre-programming" of the mental circuits, even those not strictly involved in sensori-motor function. We call these pre-programs "instinct" and "predispositions" and other similar terms. I will admit that in the human mind the amount of pre-programming is minute relative to the amount of adaptive learning, but it is still there., >Each fiber in the memory channel is like a series of millions of nodes. Within >the particular memory channel for each sense, there are thousands of >the nodal fibers. Your oldest memories were deposited and permanently, >unchangeably fixed in the first nodes of the lifetime-long memory channels. >At each moment of sensation and perception, all the simultaneously occupied >nodes among all the the memory fibers of each memory channel irrevocably fix >their contents. The group of nodes fixed on parallel fibers at one moment in >time is like a "slice" of memory of that moment in time. This is my first *major* disagreement. This is simply not supported in any way by research into brain function! Long-term memory components are frequently re-used for later memories. This is a well esablished fact of neurobiology. Mentally "advanced" forms like humans have a tremendous capability for *reconstructing* old memories from the remaining, unerasedm fragments, but the old memories are *not* kept intact forever. Instead they are selectively replaced by more relevent current memories. Also, the new memories are often patterned after the old ones, so that the structure is retained. We call this "bias", and "selective memory". An extreme example of this is found in certain songbirds that change thier song slightly each breeding season. In at least some of these species the memetic structures for song production degenerate and disappear in the non-breeding season, and are rebuilt from the ground up before each breeding season. The only *constant* portion being the pre-wired general pattern for the species song. And this annual rebuilding of memory is accompanied by shifts in physical brain mass assigned to vocalization! Admittedly there is no evidence of such extreme restructuring in humans, but there is also no reason to assume a radically different mechanism for memory! > Each sensory memory channel is like a pipeline full of nodal fibers. >The nodal fibers are already there, genetically provided and ready to >receive engrams of memory. The pipeline is gradually filling up with memory >slices all through your lifetime. The memory-slices are so densely packed >that you could live to be over a hundred years old and not run out of fresh, >unused, tabula rasa memory locations. The gradual fixation or consumption of >memory-slices is like a slow burning fuse, so long that it takes over a >hundred years to burn to the end. Even if you did run out of fresh >memory-spaces in your old age, you would still function as an intelligent >mind with full retention of your many decades of old memories and with the >loss of only your ability to remember each passing moment of the present. >You could still speak, for instance, several languages and do anything else >that you learned to do before your tabula rasa memory ran out. In light of the neurobiological research results mentioned above, and based on actual human experience in the abscence of degenerative brain disease, this is not how it works. Rather the new memories overlay the older ones in progressively greater degrees. Thus old "event" memories are often largely lost, unless they are renewed by cinstant use. Skill memories are less altered, but they also gradually deteriorate unless kept current by use. Certainly older people continue to be able to speak all, or most, languages that they ever knew. But this is more due to renewal and reconstruction than permanence. For instance, I learned to read a German fairly well in school, but now I can barely make it out, since I have had little opportunity to use it on a regular basis. Yes, I would relearn it much faster than the first time around because fragments of the original knowledge remain on which to build a newly constructed knowledge. Also, much of my early knowledge of German has been incorporated into my general knowledge of linguistics, and is kept "current" by my continued dabbling in that area. In short, while I find your basic model of the mind quite useful, I feel that you have been too influenced by a priori reasoning, and have paid little attention to recent findings in neurobiology and psychology. -- Sarima Cardolandion sarima@gryphon.CTS.COM aka Stanley Friesen rutgers!marque!gryphon!sarima Sherman Oaks, CA
brian@cat50.CS.WISC.EDU (Brian Miller) (05/02/89)
Keep "comp.ai" clean -- put neural discussions where they belong... ...in "comp.ai.neural-nets". If you don't feel comfortable writing in that group, then start another group. I'd contribute to it.