Hormones and Gain

CSGnet Archive CSG2008
1

Randy J. Nelson in his book "An Introduction to Behavioral Endocrinology (2005) states that:
In terms of their behavior, one can think of animals as being made up of three interacting components: (1) input systems (sesnsory systems), (2) integrators (the central nervous system), and (3) output systems, or effectors (e.g., muscles)… [H]ormones influence these three systems so that specific stimuli are more likely to elicit certain responses in the appropriate behavioral or social context. (p. 17)
and, for example,
… androgens, as well as other sex steroid hormones, appear to affect the likelihood of mating behaviors by reducing the threshold for these behaviors … In other words, … hormones facilitate the male response, probably by affecting the perception and processing of stimuli associated with a female. (p. 239) Hormones affect social behavior at the level of input systems; for example, androgens affect the perception of aggression-promoting stimuli associated with intermale agonistic interactions… (p. 518) In both mammals and birds, sex steroid hormones appear to affect sensory input and central nervous system processing as well as behavioral output. Androgens, for example, amplify chemosensory information associated with estrous females in the male rodent’s brain… (p. 314)
Although such statements are made from a S-R perspective, from a PCT perspective I take them to mean that certain hormones affect and change the gain of components of PCT systems.

Does this seem to be a correct interpretation of “gain” in the context of PCT?

I ask for two reasons: (1) to determine if my understanding of “gain” regarding PCT seems correct, and (2) if my interpretation seems correct, to bring this possible hormone/gain relationship to the attention of PCTers if some are not aware of it already.

With Regards,
Richard Pfau

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On Jan 31, 2008, at 19:57, “Richard H. Pfau” richardpfau4153@AOL.COM wrote:

Randy J. Nelson in his book "An Introduction to Behavioral Endocrinology (2005) states that:
In terms of their behavior, one can think of animals as being made up of three interacting components: (1) input systems (sesnsory systems), (2) integrators (the central nervous system), and (3) output systems, or effectors (e.g., muscles)… [H]ormones influence these three systems so that specific stimuli are more likely to elicit certain responses in the appropriate behavioral or social context. (p. 17)
and, for example,
… androgens, as well as other sex steroid hormones, appear to affect the likelihood of mating behaviors by reducing the threshold for these behaviors … In other words, … hormones facilitate the male response, probably by affecting the perception and processing of stimuli associated with a female. (p. 239) Hormones affect social behavior at the level of input systems; for example, androgens affect the perception of aggression-promoting stimuli associated with intermale agonistic interactions… (p. 518) In both mammals and birds, sex steroid hormones appear to affect sensory input and central nervous system processing as well as behavioral output. Androgens, for example, amplify chemosensory information associated with estrous females in the male rodent’s brain… (p. 314)

Although such statements are made from a S-R perspective, from a PCT perspective I take them to mean that certain hormones affect and change the gain of components of PCT systems.

Does this seem to be a correct interpretation of “gain” in the context of PCT?

I ask for two reasons: (1) to determine if my understanding of “gain” regarding PCT seems correct, and (2) if my interpretation seems correct, to bring this possible hormone/gain relationship to the attention of PCTers if some are not aware of it already.

With Regards,

Richard Pfau

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3

In terms of their behavior,
one can think of animals as being made up of three interacting
components: (1) input systems (sesnsory systems), (2) integrators (the
central nervous system), and (3) output systems, or effectors (e.g.,
muscles)… [H]ormones influence these three systems so that specific
stimuli are more likely to elicit certain responses in the appropriate
behavioral or social context. (p. 17)
and, for example,
… androgens, as well as other sex steroid hormones, appear to affect
the likelihood of mating behaviors by reducing the threshold for these
behaviors … In other words, … hormones facilitate the male response,
probably by affecting the perception and processing of stimuli associated
with a female. (p. 239) Hormones affect social behavior at
the level of input systems; for example, androgens affect the perception
of aggression-promoting stimuli associated with intermale agonistic
interactions… (p. 518) In both mammals and birds, sex
steroid hormones appear to affect sensory input and central nervous
system processing as well as behavioral output. Androgens, for
example, amplify chemosensory information associated with estrous females
in the male rodent’s brain… (p. 314)

Although such statements are made from a S-R perspective, from a PCT
perspective I take them to mean that certain hormones affect and change
the gain of components of PCT systems.
[From Bill Powers (2008.02.01.0839 MST)]
Richard Pfau (21008.02.01.2:57 PM 1/31/2008 -0500)]
Randy J. Nelson in his book "An Introduction to Behavioral
Endocrinology (2005) states that:
Changing gain is one possibility, although that question gets complicated
when we look at biochemistry. The main variable in the effect of a
chemical on an organ is its concentration at the point of effect; two
molecules of the same kind have more effect than one. But the kind of
molecule also matters.
A hormone like TSH has a certain amount of effect (on the thyroid’s
production of thyroxin) that depends mainly on its concentration in the
bloodstream. That effect is determined by the kind of molecule, to be
sure, but since that doesn’t change, the amount of effect is determined
mainly by the concentration.
“Gain” is the ratio of output to input (strictly speaking,
expressed on a logarithmic scale). So really, three variables are
involved whenever we speak of gain: the input variable, the output
variable, and whatever third variable (or property of the physical
device) affects the ratio. In a radio’s audio output circuit, the input
variable is the electrical audio signal representing the music, the
output variable is the sound-level coming out of the loudspeaker, and the
third variable (that determines the gain) is the angle at which the
volume control knob is set. That knob is often labeled
“Gain.”
Does the concentration of TSH merely determine the rate of output of
thyroxine, or does it vary the ratio of thyroxine output rate to the
concdentration of some other input substance inside the thyroid gland? I
don’t know, though the latter seems likely. Since the equations governing
biochemical reactions are nonlinear and involve multiplication as much as
addition, it’s hard to say. Enzymes look like good candidates for gain
control, but that’s mainly because they have such high gain in themselves
(I’m judging from an example in Hayashi and Sakamoto, The analysis of
enzyme systems, in which the gain of an allosteric enzyme in response
to variations of input concentrations appears to be about 50,000). But
it’s not that simple: the enzyme itself varies the ratio of recombination
to dissociation rates in another chemical reaction.

Savageau, who also modeled biochemical feedback systems, got around the
nonlinearities by converting all variables to logarithms, which
leads to mathematical relationships looking at lot more like the simple
ones we use in PCT. But I’m over my head here and shouldn’t get too far
into this.

I’d be happier with the excerpt you cited if the author had made clearer
distinctions between direct effects of input on output and effects of a
variable on the ratio of output to input. Maybe he does
elsewhere.

Is this anything like an answer to your question? If I knew more about
biochemistry you might get a better answer, but I don’t.

Best,

Bill P.

4

[From Bill Powers (2008.02.01.0839 MST)]

ref. Richard Pfau (21008.02.01.2:57 PM 1/31/2008 -0500)]\

Changing gain is one possibility, although that question gets complicated when we look at biochemistry.

…

“Gain” is the ratio of output to input (strictly speaking, expressed on a logarithmic scale). So really, three variables are involved whenever we speak of gain: the input variable, the output variable, and whatever third variable (or property of the physical device) affects the ratio. In a radio’s audio output circuit, the input variable is the electrical audio signal representing the music, the output variable is the sound-level coming out of the loudspeaker, and the third variable (that determines the gain) is the angle at which the volume control knob is set. That knob is often labeled “Gain.”

…

I’d be happier with the excerpt you cited if the author had made clearer distinctions between direct effects of input on output and effects of a variable on the ratio of output to input. Maybe he does elsewhere.

Bill,
Thank you for the feedback about the idea that certain hormones seem to affect and change the gain of components of PCT systems. It has been helpful.
The author cited, Randy J. Nelson, doesn’t provide any ratios in his Introduction to Behavioral Endocrinology and I’m not into the literature enough to have seen any. However, Robert Sapolsky, a neurologist, provided a metaphor related to your radio example when discussing testosterone and agression:
[Testoserone] “doesn’t cause agression. If you want a really clunky metaphor to keep in mind, testosterone does not turn on some radio playing martial military music. What testosterone does, if and only if the music’s already on, it turns up the volume.” * Giving an example of rhesus monkeys he states, “Testosterone is not creating new patterns of agression that were not there before. Testosterone is exacerbating, amplifying, increasing the volume of what was already there by social experience.” And discussing single nurons in the amydala, "… take an amygdaloid that’s firing now and then–firing, having its action potentials. Throw in testosterone, and suddenly the rate of firing increases… Testosterone does not activate those neurons. Testosterone amplifies the effect of whatever was activating those neurons." * “…testosterone is not causing agression. It amplifies pre-existin!
g tendencies.” (p. 157) (From Robert Sapolsky, “Biology and Human Behavior: The Neurological Origins of Individuality”, 2nd edition, Chantilly, Virginia: The Teaching Company, 2005, pp. 156-7)

Although not quantified, the ideas expressed seem similar to those you mentioned when discussing the concept of gain. So, for now, perhaps we can say that the idea/hypothesis that certain hormones affect and change the gain of components of PCT systems is worth considering, but requires further thought and research.

With Regards,

Richard Pfau

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[From Bill Powers (2008.02.04.0813 MST)]

Richard Pfau(09:59 AM 2/4/2008 -0500) –

“… take an
amygdaloid that’s firing now and then–firing, having its action
potentials. Throw in testosterone, and suddenly the rate of firing
increases… Testosterone does not activate those neurons.
Testosterone amplifies the effect of whatever was activating those
neurons.” “…testosterone is not causing
agression. It amplifies pre-existin! g tendencies.” (p.
157) (From Robert Sapolsky, “Biology and Human Behavior: The
Neurological Origins of Individuality”, 2nd edition, Chantilly,
Virginia: The Teaching Company, 2005, pp. 156-7)

Although not quantified, the ideas expressed seem similar to those you
mentioned when discussing the concept of gain. So, for now, perhaps
we can say that the idea/hypothesis that certain hormones affect and
change the gain of components of PCT systems is worth considering, but
requires further thought and research.

Hey, that’s very good. That’s the first thing I’ve seen in that field
that makes the distinction between input-output effects and effects on
the amplification factor. Maybe biology really is moving into the systems
age.

Best,

Bill P.