Lawry,
You've asked a lot of questions. I will do my best to answer them.
Possibly, one or two FW subscribers are specialists in neurophysiology and
will be able to amplify or correct any of the answers I give below.
<<<<
Greetings, Ray and Keith,
Many thanks for your thoughtful and helpful postings on the idea of the
holographic brain. I am taking the liberty of replying in this email to
both of you, and of troubling you with some additional questions based on
what you describe.
1) I do understand, Ray, the point you made about each cell containing all
the 'information' of a person: our DNA is replicated in each of our cells.
That the cells end up doing different things as the organism forms ( cell
development) is, as I understand it, still one of the big mysteries in
biology.
>>>>
The mechanism is known in principle. The devil is in the detail. In any
particular cell in the body (liver, kidney, brain, etc) only certain genes
in the DNA are activated. These produce the specific enzymes that are
necessary in the production of the specific proteins that the cell requires.
<<<<
But I think that this passive, activatable coding is not quite the
same as the coding of an idea, say, in the brain, no? That is, the functions
of the brain are the results of collections of neuronal cells acting
together, and not contained within a single neuron. Does this make sense?
>>>>
This is true. The components of a neural network in the cortex (the
"thinking" part -- the outer covering) are not so much individual neurons
as vertical modules of neurons. These are relatively slim columns of
neurons from the surface down through the depth of the cortex (about 1/10th
inch). In each module there are several thousand neurons belonging to five,
six or seven distinctly different types of neurons. A message coming into
the module will be shuffled up and down the module during processing and
then emerge to pass on to a module in an entirely different part of the
cortex. As training for a particular task progresses, or as a memory
becomes consolidated, then the modules involved become increasingly
specialised, quarantine themselves from the influence of neighbouring
modules and firm up connections with modules elsewhere in the cortex.
<<<<
2) Holographs.... If a holographic plate is shattered, does each piece then
still depict the whole of the original picture, or just a part of the whole?
>>>>
Yes -- each small piece recreates a copy of the whole -- though not
necessarily in as much detail.
<<<<
If brain function is generally resilient and can be restored though much of
the relevant parts of the brain have been destroyed, could it not, instead
of many duplicated learned act copies, be because the learned act is
supported by a dense and redundant set of neural pathways?
>>>>
If a network relevant to a particular task or memory (or part of it) is
destroyed then it has gone for good. There are no redundant pathways
waiting to take over. If it's a memory then it will have gone forever. If
it is a learned task, then it can only be re-learned by new, practical
learning procedures in which the brain will (with great difficulty in the
case of an adult) fashion a new network by suborning parts of other
networks. The re-learned task will never be done quite as well as
previously, and other skills belonging to the other networks will be
degraded.
<<<<
If many of the
neurons are destroyed, this restoration might be ensured by the undamaged
neurons in the original network, with only a bit of re-learning, and, if
necessary, re-growing of some of the missing neurons.
>>>>
Recent research indicates that missing (dead) neurons might be restored but
this is at very early stages of being understood. It is entirely possibly
that brain functions at a general level might well be restorable in the
future, but it is most unlikely that the micro-precision that would be
involved in the individual replacement of cells or modules will ever be
possible. Alzheimer's, Parkinson's and other short-term memory functions
might be curable, but the restoration of previous high-level skills will
almost certinly be impossible.
>>>>
It would be very
interesting to compare the recovery rates of brain-damaged individuals to
the time it takes new pathways to be adopted by learned acts that have been
damaged, and the growth of new neurons where the original redundancy was not
adequate.
>>>>
There is no redundancy, as mentioned above. This is one of the most
prevalent myths about the brain. Every single neuron in the brain of an
adult is constantly in heavy use in carrying out a specific act *or* it is
kept alive at a low level of activation. Don't bank on the possibility that
the brain can restore any sort of high-skill task.
<<<<
3) If synapses deteriorate with lack of use, might the opposite not also be
true: and if this is so, might it not be possible that carrying out mental
exercises would actually strengthen specific brain functionings?
>>>>
Yes, indeed. Synapses strengthen with use. However, there can be no general
mental exercises which can strengthen synapses -- only the the practice of
specific skills, either those already known or the learning of new ones.
<<<<
Gosh!
Might it be possible to train two entirely independent neural networks to do
the same thing, but locate them in different parts of the brain, so that if
one part were damaged, the remaining network would be able to carry on the
functioning, unimpeded?
>>>>
Not in any way possible. The whole adult brain is already occupied with
dense, dedicated network of modules with highly specific functions. Neurons
are cells needing a relatively huge consumption of oxygen merely to keep
them alive. Redundancy would be a considerable waste of resources and would
be a survival handicap.
<<<<
If a person 'can't make up their mind' about
something, might among the reasons for this be that indeed a person has
developed to independent neural nets for the same function, but that they
are just sufficiently different that in some number of cases, they end up in
conflict with each other? More speculation, I know...your thoughts?
>>>>
Yes, something like that. Decision-making in this sort of case is located
in the frontal lobes. Based on the perceptions involved in the particular
circumstances of the problem, the frontal lobes would be trying out
competition 'on paper' between two or more alternative resolutions by
repeatedly invading alternative circuits with the processed results of the
perceptions that arrive from the rear cortex. Sooner or later, one of the
alternative circuits will be strengthened at the expense of the other, and
then it will send a message to the motor strip of the cortex that will then
carry out the strategy decided upon.
<<<<
4) On this matter of Wernicke's areas and the sensory channel that is being
activated to handle a thought ("tomato"): are you saying that in Wernicke's
areas cells carry out sensory specific operations (visual/tactile/auditory,
etc.)? And that a few cells destruction might cut off a given channel's
access to the thought?
>>>>
Yes.
<<<<
If this is an adequate summary, how does the idea of synesthesia fit in, in
which experience or memory of a thing in one channel triggers a fuller
experience of it in other channels? For example: If I ask you now to
"imagine walking down a street in a quiet village, and you pass by the open
door of a bakery...."
>>>>
There's no reason why some networks of modules should not activate other
networks that have long ceased to be heavily used.
<<<<
What is happening here, in Wernicke's areas, if anything?
5) I can well imagine that functions of analysis and thinking are
distributed throughout the body and that the 'brain is human and limbs are
servants' model is lacking.
>>>>
'Brain is human and limbs are servants' is about right. However, bunches of
non-cortical neurons at locations in the spinal cord and elsewhere are not
*your* servants, but servants of perceptions from the outside (e.g. the
automatic withdrawal of a hand from a hot object).
<<<<
Why does this seem to make immediate sense to
me? In information technology, we are coming to realize that dispersed
decision-making centers, meshed together through redundant networks, may be
the superior design, in terms of speed of action, local wisdom, overall
wisdom, repair, and resilience to outside damage or attack. So it may be
that the human or other organisms, faced with the need for all of these for
hundreds of millions of years, have 'figured it out' (and I do NOT mean this
teleologically!) through the processes of evolution, and adopted this kind
of architecture for our organic information systems.
>>>>
My opinion is that you can't make comparisons between the organisation of
the modules of the cortex with the organisation of individual humans.
Entirely different stimuli are involved. It's true that big business (and
large universities) have long realised (but government civil servant
departments have generally not) that it can best function by devolving
responsibility and control to as "low" a level as possible.
But successful strategies and actions devised by the brain have, in fact,
been arrived at by successive series of highly-competitive interactions
between modules and networks of modules. The brain is more accurately
described as heirarchical rather than democratic (although the hierarchies
can suddenly switch -- as in schizophrenia).
I can't comment on what remains, I'm afraid.
Hope the above is helpful,
Keith
<<<<
6) That our understanding of the brain and human functioning is in a very
young stage is obvious, if frustrating. I have personal experience of this.
One of the areas that I have been trained in is NLP. I was able to improve
on it in some areas that were critical to me, and in the course of doing
this pushed the limit of research pretty aggressively in some the advanced
courses that I taught. In one class, challenged by one of the students, I
was able to cure him of his substantial and debilitating arthritis (elbows
and knees). He and I have stayed in close contact over the 17-18 years that
have passed since then, and he has had zero reoccurrence. Now, the amazing
thing to me is that this worked at all. I had winged an approach after he
offered curing this as a challenge to me. All I did, literally, was talk
with him, and touch him lightly on the arm. The whole thing took about 30
minutes. Everyone in the class was pretty surprised, when over the course of
the next days of the remainder of the class he reported no symptoms at all.
Of course, I don't have any understanding of how this happened, what was
happening mentally or physically. I used a metaphoric model of how people
function to guide my intervention, but metaphorical is all it was. So I am
immensely optimistic that we will find much that is fascinating and of great
human values in the decades ahead on these kinds of questions.
I like Pribram's speculations, even if they now don't seem correct; or
rather, I like the person for the speculations he offered. We are going to
need a lot of imagination and 'what-if' tolerance to come to understand
these questions. When a thing studies itself, there are bound to be great
meta-procedural challenges....
Your posts, Keith and Ray, are fascinating, and I deeply appreciate the time
you both but into them, and the generous effort you made to make them
understandable to me.
Best regards,
Lawry
>>>>
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Keith Hudson,6 Upper Camden Place, Bath BA1 5HX, England
Tel:01225 312622/444881; Fax:01225 447727; E-mail: [EMAIL PROTECTED]
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