machine brains

ray scanlon rscanlon at wsg.net
Thu Sep 18 18:31:38 EST 1997


     Thoughts and Memories

A thought and a memory are two words for the same thing. A memory
is the subjective experience of a constellation of activated
neurons. This constellation was originally activated by sensory
input. I remember it as something to move toward or to avoid or to
dismiss as irrelevant. These overtones of response may be very
weak but they are always there.

Our subjective experience of words is either of memories of words
heard or read, or of words said or written. Those who say language
is thought have made a part equal to the whole. It is plain to me
that some motor output is of words but some is not. Some thought
is the subjective experience of language motor output and some is
not. I express a word as a motor movement of the throat or the
larynx or of the hand. As with a word, so with all language. A
sentence is a complex motor movement.

The contribution of neurons toward survival is to create movement.
Neurons exist for movement, absolutely nothing else (except for a
few that are involved in hormonal release). In certain jellyfish
the sensory neurons are efferent to motor neurons without any
intermediary. Sensory input results in motor output as directly as
a light switch activates a light. The neurons of this jellyfish do
not form a neural net, they are completely dedicated to sensory
input and to the resultant movement.

In certain other jellyfish an interneuron is inserted between
sensory neuron and motor neuron. This interneuron is also
connected to other interneurons. The brain is born. After the
appearance of the interneuron is there any substantive change in
brains? Not really.

The interneurons do become clumped in ganglia, but that is only a
surface change, it is not fundamental. There is also the process
in which organisms came to have head ends and went on to
encephalization. This is also only a surface change, not
fundamental. Nothing really changed after the appearance of the
interneuron.

The first jellyfish has neurons that are only concerned with
sensory input and motor output. The second jellyfish adds
something, its neural net is now concerned with signal energy
*becoming* motor output.

Sensory input includes the activation of neurons that we
experience as feelings or emotions. I see no difference between
neurons activated as a result of signal energy coming in through
the retina and neurons activated by a body process that I
experience as happiness. I have sensory input and motor output.
That is all, that is enough.

Some would invoke a mind as homunculus. The homunculus is the
little man who sits in the center of the head, watching a TV
screen, and punching buttons. This is too simplistic for some.
They would have a mind that selects from data proffered by the
brain, manipulates that data, reaches a decision, and forwards
that decision to the brain for execution. They have created
something beautiful, but it is still an homunculus.

I dislike the word 'state' because it suggests a discreteness of
experience that I feel unwarranted. But if mental 'states' are to
be identical with brain 'states' then the basic question is
whether the soul (mind, self, intellect, homunculus) is to have
causal powers. I say no, it may only observe.

All subjective experience is of activated neurons. These activated
neurons may be thought of as incoming signal energy, as a motor
program, or as a feeling/emotion.

Signal energy comes in. My brain prepares a response, it can do no
other. The response must be provisional, my brain cannot know the
future. A sequence of pulses that will produce a movement, I call
a motor program. How our subjective experience of motor program is
thinking, I have explained elsewhere.

ray

-- 

email: rscanlon at wsg.net

If you are interested in how the brain works, visit
http://www.wsg.net/~rscanlon/brain.html



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