Belke, T. W., & Dunbar, M. (1998).
Effects of fixed-interval schedule and reinforcer duration on responding reinforced by the opportunity to run.
Journal of the Experimental Analysis of Behavior,
70, 69-78.
Two experiments investigated the effects of schedule value and
reinforcer duration on responding for the opportunity to run on
fixed-interval (FI) schedules in rats. In the first experiment, 8
male Wistar rats were exposed to FI 15-s, 30-s, and 60-s
schedules of wheel-running reinforcement. The operant was lever
pressing, and the consequence was the opportunity to run for 60
s. In the second experiment, 8 male Long-Evans rats were exposed
to reinforcer durations of 15 s, 30 s, and 90 s. The schedule of
reinforcement was an FI 60-s schedule. Results showed that
postreinforcement pause and wheel-running rates varied
systematically with reinforcer duration but not schedule value.
Local lever-pressing rates decreased with reinforcer duration.
Overall lever-pressing rates decreased with reinforcer duration
but increased with schedule value. Although the
reinforcer-duration effect is consistent with previous research,
the lack a schedule effect appears to be the result of long
postreinforcement pauses following wheel-running reinforcement
that render the manipulation of the interval requirement
ineffective.
Key words: fixed-interval schedule, reinforcer duration, wheel
running, lever press, rats