the liver and the brain
rscanlon at nycap.rr.com
Tue Aug 31 18:03:12 EST 2004
David Longley writes:
> Don't you think sleight-of-hand and metaphysics deserves derision?
Well, then let's drop all the sleight-of-hand and metaphysical
prejudices and talk about the brain.
Since the neural net (interneurons) appeared in Cnidaria, what has
changed? For one thing, the DNA has evolved to a point where it is
able to construct a whole series of motor program generators, groups
of neurons that when triggered produce a motor act. These generators
can be modified by experience but they are not learned. We are born
The location in the nervous system of some of these motor program
generators can be more or less specified.
Orofaciopharyngeal movements: facial expression, vocalization,
licking, chewing, and swallowing in the dorsolateral hindbrain.
Reaching, grasping, and manipulating in the spinal cord (cervical
There are more, of course, but we take these for starters.
(The specialist talks about controllers, imitators, motoneuron pools,
The important thing is that these are not, repeat not, learnedthey
are constructed by the DNA. Under vocalization are the phonemesalso
provided by the DNA.
Some synapses in the nervous system can be altered by experience. This
allows us to string the phonemes together into language.
This lays the groundwork for a scientific explanation of brain action.
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