Systems Biology

CSGnet Archive CSG2002
1

[From Rick Marken (2002.03.07.0840)]

Bill Powers (2002.03.07.0855 MST)

See _Science_, 1 March 2002, Vol. 295, No. 5580,pp. 1664 ff:

Reverse Engineering of Biological Complexity, by Marie E. Csete ( U Mich
medical school) and John C. Doyle (CA Inst of Tech, Pasadena).

On page 1667 a section starts called "Elementary feedback concepts," which
introduces classical control theory quite correctly in the context of
biological systems.

No reference to PCT, of course.

Thanks. I'll make copy today if it's in. Doyle works right near me at Cal
Tech, apparently. It might be interesting to discuss this with him.

On the subject of getting control theory right without reference to (or
knowledge of) PCT, Isaac Kurtzer (who has been a great source of PCT relevant
literature; keep it comin') pointed me to the following article about a month
ago:

Mechsner F, Kerzel D, Knoblich G, Prinz W. (2001) Perceptual basis of
bimanual coordination. _Nature_ , Nov 1;414(6859):69-73

Mechsner did some truly ingenious experiments (simple, clear, devastating --
my kind of experiments) that show very clearly that coordination is control
of input, not output. It's amazing to me that Mechsner was able to devise
these experiments with no knowledge of PCT. But he did. I've been in touch
with Mechsner, who is trained as a biologist, not a psychologist, and he is
_very_ interested in PCT, though he was completely unaware of its existence
when he did his research.

Best regards

Rick

···

--
Richard S. Marken, Ph.D.
The RAND Corporation
PO Box 2138
1700 Main Street
Santa Monica, CA 90407-2138
Tel: 310-393-0411 x7971
Fax: 310-451-7018
E-mail: rmarken@rand.org

2

[From Bill Powers (2002.03.07.0855 MST)]

See _Science_, 1 March 2002, Vol. 295, No. 5580,pp. 1664 ff:

Reverse Engineering of Biological Complexity, by Marie E. Csete ( U Mich
medical school) and John C. Doyle (CA Inst of Tech, Pasadena).

On page 1667 a section starts called "Elementary feedback concepts," which
introduces classical control theory quite correctly in the context of
biological systems.

No reference to PCT, of course.

Best,

Bill P.

3

[From Rick Marken (2002.03.08.1430)]

Fred Nickols (2002.03.08.1553 ET)] --

>Rick Marken (2002.03.07.0840)]

>Mechsner did some truly ingenious experiments (simple, clear, devastating --
>my kind of experiments) that show very clearly that coordination is control
>of input, not output. It's amazing to me that Mechsner was able to devise
>these experiments with no knowledge of PCT. But he did. I've been in touch
>with Mechsner, who is trained as a biologist, not a psychologist, and he is
>_very_ interested in PCT, though he was completely unaware of its existence
>when he did his research.

A question -- mainly out of curiosity. If someone understood control
theory isn't it conceivable that they could arrive at many of the same
conclusions and conduct some of those "truly ingenious" experiments --
without knowing about PCT?

Absolutely. Mechsner is certainly one of those someones.

Best

Rick

···

--
Richard S. Marken, Ph.D.
The RAND Corporation
PO Box 2138
1700 Main Street
Santa Monica, CA 90407-2138
Tel: 310-393-0411 x7971
Fax: 310-451-7018
E-mail: rmarken@rand.org

4

[From Fred Nickols (2002.03.08.1553 ET)] --

Rick Marken (2002.03.07.0840)]

<snip>

On the subject of getting control theory right without reference to (or
knowledge of) PCT, Isaac Kurtzer (who has been a great source of PCT relevant
literature; keep it comin') pointed me to the following article about a month
ago:

Mechsner F, Kerzel D, Knoblich G, Prinz W. (2001) Perceptual basis of
bimanual coordination. _Nature_ , Nov 1;414(6859):69-73

Mechsner did some truly ingenious experiments (simple, clear, devastating --
my kind of experiments) that show very clearly that coordination is control
of input, not output. It's amazing to me that Mechsner was able to devise
these experiments with no knowledge of PCT. But he did. I've been in touch
with Mechsner, who is trained as a biologist, not a psychologist, and he is
_very_ interested in PCT, though he was completely unaware of its existence
when he did his research.

A question -- mainly out of curiosity. If someone understood control
theory isn't it conceivable that they could arrive at many of the same
conclusions and conduct some of those "truly ingenious" experiments --
without knowing about PCT?

Regards,

Fred Nickols
740.397.2363
nickols@att.net
"Assistance at A Distance"
http://home.att.net/~nickols/articles.htm

5

[From Rick Marken (2002.03.13.0830)]

Bill Powers (2002.03.07.0855 MST) --

See _Science_, 1 March 2002, Vol. 295, No. 5580,pp. 1664 ff:

Reverse Engineering of Biological Complexity, by Marie E. Csete ( U

Mich

medical school) and John C. Doyle (CA Inst of Tech, Pasadena).

On page 1667 a section starts called "Elementary feedback concepts,"

which

introduces classical control theory quite correctly in the context of
biological systems.

Well, I finally read it. I thought it was crap. More mathematical point
missing. Very tiresome. But since it was the stimulus (in the
disturbance to a controlled variable sense;-)) for you writing "The
Rationale and Terminology of PCT" paper, I suppose it has served a
useful purpose. The "Rationale.." paper is _great_. I hope you try to
publish it in some place where folks like Ceste and Doyle will find it.

Best regards

Rick

···

--
Richard S. Marken, Ph.D.
The RAND Corporation
PO Box 2138
1700 Main Street
Santa Monica, CA 90407-2138
Tel: 310-393-0411 x7971
Fax: 310-451-7018
E-mail: rmarken@rand.org