Dr. Norbert Wiener, who pioneered in the development
of goal-seeking mechanisms in World War II, believes
that something very similar to the foregoing happens in
the human nervous system whenever you perform any
purposeful activity—even in such a simple goal-seeking
situation as picking up a package of cigarettes from a
table.
We are able to accomplish the goal of picking up the
cigarettes because of an automatic mechanism, and not
by "will" and forebrain thinking alone. All that the forebrain
does is to select the goal, trigger it into action by
desire, and feed information to the automatic mechanism
so that your hand continually corrects its course.
In the first place, said Dr. Wiener, only an anatomist
would know all the muscles involved in picking up the
cigarettes. And if you knew, you would not consciously
say to yourself, "I must contract my shoulder muscles to
elevate my arm, now I must contract my triceps to extend
my arm, etc." You just go ahead and pick up the cigarettes,
and are not conscious of issuing orders to individual
muscles, nor of computing just how much contraction
is needed.
When "YOU" select the goal and trigger it into action,
an automatic mechanism takes over. First of all, you have
picked up cigarettes, or performed similar movements before.
Your automatic mechanism has "learned" something
of the correct response needed. Next, your automatic
mechanism uses feedback data furnished to the brain by
your eyes, which tells it "the degree to which the cigarettes
are not picked up." This feedback data enables the
automatic mechanism to continually correct the motion
of your hand, until it is steered to the cigarettes.