| dc.description.abstract | In two separate experiments, an 8 rat 8 station operant arena
was used to study resistance to extinction to test learning and
optimal foraging theories of behaviour. The learning theory, called
the generalized decrement theory (GDT) assumes that increased
resistance to extinction will occur with increased partial
reinforcement schedules. It becomes more difficult to distinguish
the acquisition phase from the extinction phase as the time
interval increases and as a result less generalized decrement is
observed during extinction. An extention of optimal foraging
theory called the skill pool effect (SPE) describes a foraging
group as composed of either active producers (active participants
in locating food) or scroungers (passive participants who
specialize in following others to food sites). The producers
determine when to leave a food patch and move on. The GDT and SPE
were tested by allowing the population access to all stations with
some bars capable of producing food reward and others as not
producing food reward. For three consecutive sessions the
population was exposed to either 1,2,4 or 8 bars functioning and
then extinguished under the same conditions. In Experiment 1, an
attempt was made to provide an equal distribution of food as the
number of functioning bars decreased. This was done by enriching
schedules of reinforcement as the functioning bars decreased. In
Experiment 2, the schedule of reinforcement was held constant at a
VI of 120 in order to control for any schedule differences.
According to the GDT, the population should manifest the greatest
number of responses with the least amount of bars working, during
extinction. However, the SPE would anticipate the greatest number
of responses occurring with the most amount of bars functioning.
The results showed the greatest number of responses occurring with
4 bars functioning. This occurred in both experiments. The
findings did not support either the GDT or the SPE. It appears
that additional work is needed to account for the above phenomenon. | |
