[From Shannon Williams (960103)]
Bill Powers (960101.1115)--
Suppose we're controlling the perceptual signal y at a value y0. The
error, y0 - y, is amplified and send to two output functions, which
affect the values x1 and x2 in appropriate directions. The result will
not be to bring x1 and x2 to any particular values, but to bring y to
the value y0.
I am excited! If X1 and X2 are considered potential perceptions for
another loop, then this is how you build an evolving reference.
See it this way:
ยทยทยท
****************
1) At first the infant has some disturbance (hunger, cold, ?)
2) If a perception fixes the disturbance then he tries to maintain that
perception. This happens to decrease the likely hood of him
encountering the disturbance again. In other words, a perception that
proves successful becomes a reference.
3) The reason that #2 works is because perception generates (causes)
output. In other words, there is a direct relationship between
what you perceive and how you behave.
In other words:
***************
p = the (learned) perception/interpretation of an input.
1) y1 = e0 = y0 - p0(y)
2) y2 = e1 = y1 - p1(y)
3) y3 = e2 = y2 - p2(y)
etc.
or:
y0 = p0(y) + p1(y) + p2(y) + p3(y) + ... + pi(y) + ei
Also lets say you have another reference:
*****************************************
1) r1 = E0 = r0 - F0(y)
2) r2 = E1 = r1 - F1(y)
3) r3 = E2 = r2 - F2(y)
if it happens that E1 = e1 then r0 = F0(y) + F1(y) + p2(y) + ...
In other words an interpretaion used to fix y0 can be used to fix r0.
So the scenario is:
*******************
0) you start with an error signal e.
1) you have a perception p.
2) you have an output to the world O.
3) diferent p's generate (cause) different Os.
4) When an error signal occurs p is (internally) changed and changed and
changed until the error signal goes away. (O is linked automaticaly to p)
In other words: An interpretaion of the input from the world is found which
causes the error to go away. This interpretation DIRECTLY generates your
behavior.
5) If the interpretaion/perception, p, is successful again and again, then
p becomes a reference itself. So that if p is not maintained, then an
error is generated.
This is kinda what I see:
> > > > >
\|/ input \|/ from \|/ the \|/ world \|/
-------------------------------------------------------------------------
------------------ ------------------ ------------------
> perception #1 | | perception #2 | | perception #3 |
------------------ ------------------ ------------------
> > > > > >
\|/ \|/ \|/ \|/ \|/ \|/
r1----> C r2 ----> C r3 ----> C
> > >
e1 e2 e3
\|/ \|/ \|/
------------------------------------------------------------------------
------------------ ------------------ ------------------
> perception #4 | | perception #5 | | perception #6 |
------------------ ------------------ ------------------
> > > > > >
\|/ \|/ \|/ \|/ \|/ \|/
r4----> C r5 ----> C r6 ----> C
> > >
e4 e5 e6
\|/ \|/ \|/
-------------------------------------------------------------------------
1) When each perception above is realized, an output is automatically
generated. In other words, each perception is an input to some or many
loops. One of those loops eventually causes behavior.
2) All of the interpretations above can share hardware.
3) I imagine the references above to have evolved in the brain, but once
they have evolved they seem as concrete as the original references.
4) The reference could work like this: There is something that remembers
when it is not stimulated (or is stimulated?). As it gets to be stimulated
less and less, then there comes a point when it generates a signal if it
is stimulated. In other words, when a neural firing pattern becomes
recognizeable then when that pattern is not generated an error occurs.
Going back to the project:
**************************
Suppose that x1 is the magnitude of one formant and x2 is the magnitude
of another. We can assume that the same phoneme will be heard if some
function of x1 and x2 remains constant.
I think that how we perceive x1 and x2 depends on how we have learned our
interpretations. (Our interpretations are just one segment of the loop.)
By changing the reference level for the perceptual signal of the
phoneme-control system, a higher system can change the phoneme that is
heard.
I do not think that this is right. I think that our perceptions create our
references.
I think it's best to start by defining what
has to evolve; then we can see what aspects of the system need to be
modified during evolution.
OK.
-Shannon