Three experiments have examined whether a whole-partial
reversal effect is due to shift in reinforcement density across
phases, between whole and partial reversal in both matching (or
nonmatching) -to-sample discriminations using 12 different
stimulus sets (Experiments 1 and 2) and three concurrent
discriminations (Experiment 3). In Experiments 1 and 2, rats were
trained on nonmatching (or matching) -to-sample discriminations
and then either given reversal training on 12 stimulus sets (W), on
9 out of them (P-9), on 6 out of them (P-6), or 3 out of them (P-3).
Group W reversed faster than the other three partial groups. Group
P-3 reversed faster than Group P-6, which in turn reversed faster
than Group P-9. In Experiment 3, rats were concurrently trained on
three discrimination tasks and then either given reversal on a total
of three discrimination tasks (W), on two out of them (P-2), or on
one out of them (P-1). Group W reversed faster than Group P-1,
which in turn reversed faster than Group P-2 after overtraining.
These findings provide evidence that rats form functional classes,
and that the whole-partial reversal effect is not due to shift in
"REVERSAL LEARNING IN CONDITIONAL DISCRIMINATIONS IS NOT CONTROLLED BY REINFORCER DENSITY,"
The Psychological Record: Vol. 50
, Article 8.
Available at: http://opensiuc.lib.siu.edu/tpr/vol50/iss1/8