# pigeon control of missile, Back to the Future

**URL:** <http://discourse.iapct.org/t/pigeon-control-of-missile-back-to-the-future/14602>\
**Category:** CSG1996\
**Created:** [August 18, 1996, 9:00pm UTC](http://discourse.iapct.org/t/pigeon-control-of-missile-back-to-the-future/14602 "1996-08-18T21:00:14Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Richard\_Marken](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/r/9fc348/32.png) [@Richard\_Marken](http://discourse.iapct.org/u/Richard_Marken)\
**Post date:** [August 18, 1996, 9:00pm UTC](http://discourse.iapct.org/t/pigeon-control-of-missile-back-to-the-future/14602/1 "1996-08-18T21:00:14Z")

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[From Rick Marken (960818.1400)]

Me:

> The accuracy of inertial guidance systems has nothing to do with it. All  
> you need is a circuit that does what the pigeon does: controls a  
> representation of the 2-D position of the ship. The input to the circuit is  
> an electronic representation of this variable; we know that this input is  
> available because it is being converted into a visual display for the pigeon.

Martin Taylor (960816 17:00) --

> You are in the wrong business, Rick. In two sentences you solved a  
> problem that bedevilled computer science researchers for five decades.

> Marvellous. I am humbled.

It's easy once you learn to look at control from a PCT perspective;-)

However, under the assumption that you may have waxing facet1ous, I will  
point out that I was responding to the notion that the problem being  
solved with the bird in the bomb was the design of a "navigation system".  
Bruce Abbott had suggested that Skinner was capitalizing on the pigeon's  
navigational capabilities when he used the pigeon to guide a bomb to a  
target. I think of "navigational capabilites" as the ability to determine  
one's current position, select a course to a target position and "steer  
the course" towards that target position. So from my point of view the  
pigeon in the bomb was not navigating -- or using any special navigational  
capabilities.

What I thought the pigeon was doing, at first, was pecking to control  
a two dimensional representation of the position of the bomb (or target).  
No navigation would be involved here; just the kind of control that  
Skinner was studying (and not noticing) all along. This would have meant  
that the pigeon could have been easily replaced by a simple control system  
(just as a human can be easily replaced by a simple control system in  
our compensatory tracking tasks). It turned out, however, that my concept  
of what the bird was doing was wrong; it was not pecking to control an  
image of the bomb (or target); it was pecking to control a relationship  
between its beak and the target. The consequence of these pecks was used as  
a representation of the position of the target in an electro/mechanical  
control system. This perceptual representaton of target position was the  
variable controlled by the control system.

So the problem that was solved by the pigeon was not a "navigational"  
problem; nor was it (as I had thought) a far simpler control problem. The  
problem solved by the pigeon was a \_perceptual\_ problem; the problem of  
representing the controlled variable (target position) to the control  
system. This is the same problem that exists for "smart" (I'd prefer  
to call them "incompetent" in honor of Asimov's inspiring observation)  
bombs today; the problem is not navigational; it's perceptual. The bomb  
has to perceive the location of what should constitute the "target" in  
the input sensory field. If the bomb could reliably perceive target  
location, the solution to the navigation problem would be a simple  
control system.

Hans Blom (960729c) --

> What I \_do\_ know is that MCT "explains" (has similarities to)  
> real world phenomena that PCT cannot model.

Martin Taylor (960816 15:10) --

> I'm sorry, Hans, but do you have any examples?

As you can see, Martin, it has been some time since Hans made this  
claim. He even proposed an experiment to test the relative merits of  
MCT and PCT . I'm ready to run it as soon as Hans approves the method.  
I'm sure Hans is just taking his time because he knows how devastating  
it will be for me to find out that MCT is better than PCT;-)

Phil Runkel (16 Aug 96) --

> I am confident that the next great breakthrough will be, in effect, the  
> discovery of Powers's 1973 book

Well put, Phil. Like the "breakthrough" of Mendelian genetics, the  
breakthrough of Powersean behavioristics will be a case of "Back  
to the Future".

Best

Rick