Reed, P. (2003).
The effect of signaled reinforcement on rats' fixed-interval responding.
Journal of the Experimental Analysis of Behavior,
79, 367-382.
Four experiments examined the effect on rats' response rate of
presenting a brief (500 ms) stimulus simultaneously with the
delivery of food on fixed-interval (FI) schedules. In Experiment
1, reinforcement signals that were spatially diffuse (both tones
and lights) elevated rates of responding, but responding was
attenuated by localized visual stimuli. The remaining experiments
examined the signal-induced potentiation of responding. In
Experiment 2, a tone reinforcement signal potentiated response
rates on an FI schedule, but attenuated response rates on a
variable-interval (VI) schedule. This difference was obtained
even though the overall rate of responding was equated on the two
schedules before the introduction of the signal. Signal-induced
potentiation of responding occurred over a range of FI values
employed in Experiment 3. In Experiment 4, presenting a
reinforcement signal when high local rates of response had
occurred immediately before reinforcement resulted in potentiated
rates of responding on an FI schedule. The opposite effect on
response rate occurred when the reinforcement signal followed
only low local rates of response. These results indicate that a
variety of factors influence the effects of a reinforcement
signal. They imply, however, that the local rate of response at
the time of reinforcement is a key factor in establishing the
nature of the signaling effect.
Key words: reinforcement signal, response learning, fixed-interval, variable-interval,
mulltiple schedules, rat