IUBio

machine brains

fox_emma at hotmail.com fox_emma at hotmail.com
Tue Jan 26 06:31:45 EST 1999


In article <36abd06d.0 at ns2.wsg.net>,
  "Ray Scanlon" <rscanlon at wsg.net> wrote:
>
>
> Joe Kilner wrote in message <787me7$gcl$1 at pegasus.csx.cam.ac.uk>...
> >
> >Ray Scanlon wrote in message <36a73cc5.0 at ns2.wsg.net>...
> >
>
> >>The brain has all the neurons need to think and decide, we apply Occam's
> >>Razor to exclude any need for soul (mind) or for the need of interaction
> >>between soul and brain.
> >>
> >
> >Oh!  I see!  We know what the criteria for thinking are now do we?  We know
> >what is necessary to make a decision.  And we _know_ that the brain can
> >fulfill these criteria!  Oh, in that case then you are right the soul does
> >not need to interact with the brain at all.  If this is true then can you
> >please tell me what thinking and deciding are?  And what do you need to do
> >them?  And how _exactly_ do you *know* that you are right - especially if
> >your answer is based on any of the science of the last few hundred years,
> >nothing can ever be known from science - we can just have better or worse
> >reasons to believe in it!
>
> You ask two questions: 1. What is thinking and deciding, and 2. How do I
> know I am right.
>
> Good! Let's cut to the chase.
>
> A set of one or more neurons that are simultaneously active is a
> constellation. A series of constellations that are active in an unvarying
> sequence (such as a melody) is a chain. A constellation that may or may not
> follow another constellation is an association. Signals from a constellation
> in the basal ganglia and/or the cerebellum is a motor program. A motor
> program can be thought of as the pulses of air passing through the holes in
> a roll in a player piano.
>
> Thinking and deciding evolved in mammals with the appearance of the
> reticular nucleus of the thalamus. This nucleus enfolds the thalamus as a
> blanket. It (or rather the neurons that comprise it) functions by inhibiting
> the relay neurons in the medial geniculate body (auditory system), lateral
> geniculate body (visual system), ventral posterior medial-ventral posterior
> lateral complex (somatosensory system), and the ventral anterior-ventral
> lateral complex (motor programs proceeding from the basal ganglia and the
> cerebellum).
>
> Any frustration, failure, or body damage (pain) that follows a motor act is
> a bad result. Any pleasure that follows a motor act is a good result.
>
> When a bad result happens, recently active constellations have any
> excitatory synapses they may have in the reticular nucleus of the thalamus
> strengthened. If one or more of these constellations is active in the
> future, the reticular nucleus of the thalamus will be excited. When this
> happens signal energy and motor programs will be held up in the thalamus as
> sketched out above. In the absence of incoming signal energy, constellations
> in the neocortex will associate. Each active constellation will take part in
> activating motor programs in the basal ganglia. This will continue as long
> as
> the reticular nucleus of the thalamus is excited. The mammal is thinking. If
> one of the motor programs does not have a bad history, the reticular nucleus
> of the thalamus will cease being active and the motor program will proceed
> to the motor and pre-motor cortex. The mammal has decided.
>
> When a good result happens, recently active constellations will have any
> inhibitory synapses they may have in the reticular nucleus of the thalamus
> strengthened. In the future these inhibitory synapses will be (in effect)
> weighed against excitatory synapses to determine the condition of the
> reticular nucleus of the thalamus.
>
> In addition the brainstem has inhibitory synapses on the neurons of the
> reticular nucleus of the thalamus. As time passes with the reticular nucleus
> of the thalamus active, the pressure from the brainstem will build up until
> it overcomes the activation from previous bad results. The reticular nucleus
> of the thalamus will be inhibited and action will ensue. The results may be
> bad but there will be action.
>
> A rat hesitating before a piece of cheese and a mathematician working out a
> theorem use exactly the same mechanisms.
>
> This is thinking and decision.
>
> The level of activity in the reticular nucleus of the thalamus is dependent
> on the past history of bad and good and on the wiring constructed by the
> DNA. If I have an active constellation, a thought, and the reticular nucleus
> of my thalamus is inhibited, I know truth. This is how I know I am right and
> it is how you know you are right. Thus there is room in the world for many
> truths. There is also absolute truth as wired by the DNA.
>
> This argument is best evaluated by a computer engineer who has had
> experience in microprogramming and has a foundation in neuroscience, it is
> both a partial  explanation of how the brain works and a partial description
> of a machine brain.
>
> Ray
> Those interested in how the brain works might look at
> www.wsg.net/~rscanlon/brain.html
>

You obviously have your neurology down pat.  I have no argument with you
there.	I am a believer in simple neurological decision making for simple
situations,  I know there is circuitry out there that can decide far more
efficiently than a product of nature.  I am still, however, a little reticent
about taking the soul/mind out of complex human/ethical decision making, for
which I believe the capacity for human emotion is required.  My question to
you is:  Is the neurology of the amygdala ever involved in your decision
making scenario?  Is brain biochemistry ever involved?

I am interested in the biological basis for human emotion, but am having a
little trouble satisfying myself re the mystery of the Amygdala, which seems
to be only implicated in the occurance of emotions...  If this is out of your
field of interest, please feel free to ignore this message.

Emma

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