Nf. Haddad et al., WHEEL-RUNNING IN DISCRETE TRIAL AND OPERANT PARADIGMS UNDER VARIOUS EFFORT REQUIREMENTS, Physiology & behavior, 56(3), 1994, pp. 487-493
Two experiments were conducted in which the wheel-running behavior of
rats under various effort requirements was investigated. The specific
effort requirements were obtained by varying the tangential force requ
ired to initiate wheel movement. In the first experiment, a discrete t
rial preparation was used in which 4 groups of rats received training
with high effort levels of 90, 110, 130, and 150 g. The results showed
that increasing effort requirements slowed the rate of acquisition, l
owered the asymptotic running speeds, and reduced resistance to extinc
tion. In the second experiment, using an operant preparation, running
speeds were examined for baseline (nonreinforced) and fixed-interval 1
min schedules of reinforcement at effort levels of 45, 90, and 180 g.
The results clearly showed wheel-running to be schedule-induced. Howe
ver, the effects of effort on Fl behavior were less clear due to incon
sistencies between subjects. Results are discussed in terms of the pot
ential benefits of bridging operant and discrete trial preparations an
d methods for studying the effects of effort on animal behavior.