Belke, T. W. (1997).
Running and responding reinforced by the opportunity to run: Effect of reinforcer duration.
Journal of the Experimental Analysis of Behavior,
67, 337-351.
The present study investigated the effect of reinforcer duration
on running and on responding reinforced by the opportunity to
run. Eleven male Wistar rats responded on levers for the
opportunity to run in a running wheel. Opportunities to run were
programmed to occur on a tandem fixed-ratio 1 variable-interval
30-s reinforcement schedule. Reinforcer duration varied across
conditions from 30 to 120 s. As reinforcer duration increased,
the rates of running and lever pressing declined, and latency to
lever press increased. The increase in latency to respond was
consistent with findings that unconditioned inhibitory
aftereffects of reinforcement increase with reinforcer magnitude.
The decrease in local lever-pressing rates, however, was
inconsistent with the view that response strength increases with
the duration of the reinforcer. Response rate varied inversely,
not directly, with reinforcer duration. Furthermore,
within-session data challenge satiation, fatigue, and response
deprivation as determinants of the observed changes in running
and responding. In sum, the results point to the need for further
research with nonappetitive forms of reinforcement.
Key words: reinforcer duration, wheel running, lever press, rats