[From Bruce Abbott (951025.1710 EST)]
This is Phil Runkel on 25 October 95 asking a question of Rick Marken
about his post of 19 Oct.
You said, "... starving rats pressing and eating as fast as they
can; ... the organisms in these tasks are not in control of food." But
are the rats not eating with purpose, and therefore with a perception
they are controlling?
Phil, Rick was just having a bad day, having been roused from net
hibernation before he had gotten enough sleep. What my analysis showed was
that the rats in the experiment to which Rick refers were not varying their
response rates across different ratio schedule requirements, although this
meant that at higher ratios the rats would earn less food owing to the extra
time required to complete the ratio. Thus the rats failed to control food
rate by compensatory changes in response rate. But Rick believes that the
rats SHOULD have controlled food rate; they didn't, so they must have been
up against some limit that prevented them from adjusting their response
rate. Their control system must have been bang up against the stops, i.e.,
the rats must have been responding as fast as they could and thus could not
increase their response rates any further to counter the disturbance. And
if the system had been driven into saturation, it must have been overdriven
by a huge error signal; thus the rats must have been starving.
The only problem with this perfectly reasonable control-system analysis is
that it is inconsistent with the facts. The rats were tested at two levels
of deprivation and under both conditions gave no evidence that they were
attempting to control the rate of food delivery by varying their response
rates, even though the response rate under low deprivation was considerably
less than the rate under higher deprivation. So much for starving rats.
Regards,
Bruce