Mr Powers, you’re so warm! Thanks for your explanation.
Does it means like this? A sequence of “reference signals” stored on the X axis, and when it’s implemented along the X axis, actions generated on the Y axis make the controlled variable approach the reference one. Meanwhile, there’s no fixed plans, actions adjust the controlled variable against disturbance. According to my understanding, I drew a figure (attach file).
The following text has nothing to do with PCT, it’s my brief statement. So to those who are not interested in me, I’m sorry for disturbing you.
These days, I’m interested in building a new architecture of programming, which adapts to machine itself in low level while our advanced programming languages adapt to human beings. The advanced language like C/C++ is a kind of script based on our language. If we want a
machine to adjust or make programs itself, it will need to understand our languages first when using C/C++. Using genetic algorithm to generate programs won’t be the best choice. It costs creatures lots of time and bodies in evolution.
If we want to build a self-programming machine, a new structure is needed. So I’m thinking of how behaviors stored in our brains since they’re a kind of programs. The program is a set of controlling, isn’t it? I turned to PCT for help, after Archy (little bug Mr. Kennaway made) came across me.
I’ll use a kind of nodes, which is stronger than neurons and in lower level than agents, to be the basic unit of this new structure. A network links one node to another. Every node has a special variable called “temperature”. To those perceptual nodes like sensors, their temperature is used to sign how much they are different from others. To those control nodes, the temperature is used to sign how
much they affect on the controlled variables.
So, the sequence I referred to before is not a fixed chain. After a node was implemented, it will boost the temperature of next step. In this way, the behavior may be broken in the half way since there’s other disturbance on the temperature. So, the “activation” referred to in the last mail related to this thought.
And, I have lots of thoughts on this, if you wish or fell confusing of what I said, you could contact me directly at frank_bbbw@yahoo.com.cn. You all are my teachers.
Now I’m a freshman at Shanghai Jiao Tong University, P.R.China. So, what I said here seems pompous and naive. Please forgive me for my impertinence.
Best regards,
Bo Wang
Bill Powers powers_w@FRONTIER.NET 写道：
[From Bill Powers (2006.06.19.0730 MDT)]
Wang Bo (2006.06.18) –
What’s your opinion on how behaviours stored in the brain?
A series of supposed inputs and outputs？
Or a series of intended input?According to PCT, it seems to squints towards the second one. A
sequence of intended inputs stored in brain. When the head of chain
was actived(by some stimulus), every node generates output according
to the intended input in it.Or you have other ideas?
Yes, you are correct that PCT would be consistent with the second
one. As you probably know, the control of sequences is
just one level
of organization that has been proposed. There are ten others, some at
higher levels and others at lower levels. Only the lower levels have
been put to any serious tests – the rest are still only hypotheses
based on informal observations.
However, the idea that an external stimulus activates a stored
sequence is different from the PCT idea. In PCT, stimuli do not cause
behavior, but just the opposite. The organism produces behavior
(actions, movements, physical forces) as a means of causing
perceptions to occur, and it adjusts the behavior to make the
perceptions match internal “reference signals”. Because the behavior
acts on perceptions through the external world, and perceptions
represent the external world, we can often observe aspects of the
environment bing controlled when we see another organism behaving,
expecially when we perceive in the same way that the observed
organism perceives.
Independent external influences can change one or more perceptions
that an organism is controlling, by acting on the world that the
organism is sensing. Such influences are called disturbances. If a
perception is being controlled, the organism will act to prevent it
from changing, and this action will appear to be a “response” to a
“stimulus”. This is how the appearance of stimuli causing responses
is explained in PCT. We identify such “stimuli” as disturbances of
controlled variables.
At the sequence level of organization, the theory says, a sequence of
perceptions would be stored as potential reference signals, like
memories of the elements of the sequence. When a higher system
specifies that a certain sequence is to be perceived, the organism
will act (through lower-level systems) to create that sequence,
matching the perceived sequence to the reference sequence. But in
general, this will not result in a specific sequence of behaviors –
postures, movements, or forces – because the environment normally is
changing. Repeating the same sequence of actions will not cause the
same sequence of results to occur. In order for a specific sequence
of perceived results to occur, the actions must vary so as to
compensate for variations in the environment. This is how the subject
of negative feedback control arises in PCT. Only a negative feedback
control system is able to alter its actions to keep the perceived
result the same when unpredictable and invisible disturbances occur.
Systems based on stimulus and response cannot do this.
I hope this is not ten times as much information as you wanted, and
that I have at least partially answered your question. I would like
to know what your interest in PCT is.-- can you tell us a little
about yourself?
Best regards,
Bill P.
