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[Neuroscience] Re: Wherefore art thou Neuron Code?

Glen M. Sizemore via neur-sci%40net.bio.net (by gmsizemore2 from yahoo.com)
Sat Apr 7 09:35:34 EST 2007


Here's an experiment - you tell me what the outcome would be based on your 
fanciful notions:



This experiment involves pigeons pecking illuminated Plexiglas "keys" 
usually mounted behind a circular aperture in an aluminum wall of an operant 
chamber.



Beginning of trial: Two keys are transilluminated, both with white lights, 
and th pigeon can peck either key. Pecking the right hand key causes both 
lights to be extinguished. After t s, both keys are illuminated, one with a 
red light, the other with green (and the position is random), and the pigeon 
can peck either key. If the pigeon pecks the red key, the lights go out and, 
1.0 s later, a solenoid-operated feeder swings into position for 3.0 s. This 
is followed by a 20.0 s inter-trial interval (ITI). If, on the other hand, 
the pigeon pecks the green key, the lights go out, there is a 4.0 s delay, 
and the pigeon gets 12.0 s access to the feeder at the end of the delay. 
This is followed by an 8.0 s ITI. If, however, the pigeon had pecked the 
left-hand key (when both lights are white - i.e., at the beginning of the 
trial) there is a delay of t s, at the end of which only one key is lit, and 
it is the green key. Pecking the green key has the same effect as it does on 
the trials in which it is present with the red alternative.



What does the pigeon do under these circumstances when t=0.2 s? What is it 
likely to do when t=20.0 s? Explain which white key is pecked. If the 
red/green choice comes up, what does the pigeon do (if only the green 
alternative is present the pigeon can only do one experimenter-defined 
thing). If the red/green alternative is presented anyway as a probe (when 
the procedure would otherwise dictate only the green key being illuminated) 
what does the pigeon do?



Since all behavior is just a matter of "TD E/I-minimization," you should 
have no trouble telling me, qualitatively, what happens to behavior as a 
function of manipulating t. Right? No fair consulting any literature or 
textbook - Jesus is watching.



<snip>






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