Reed, P. & Doughty, A. H. (2005).
Within-subject testing of the signaled-reinforcement effect on operant
responding as measured by response rate and resistance to change.
Journal of the Experimental Analysis of Behavior, 83, 31-45.
Response rates under random-interval schedules are lower when a brief (500 ms)
signal accompanies reinforcement than when there is no signal. The present
study examined this signaled-reinforcement effect and its relation to resistance
to change. In Experiment 1, rats responded on a multiple random-interval 60-s
random-interval 60-s schedule, with signaled reinforcement in only one component.
Response resistance to alternative reinforcement, prefeeding, and extinction was
compared between these components. Lower response rates, and greater resistance
to change, occurred in the component with the reinforcement signal. In
Experiment 2, response rates and resistance to change were compared after
training on a multiple random-interval 60-s random-interval 60-s schedule
in which reinforcer delivery was unsignaled in one component and a
response-produced uncorrelated stimulus was presented in the other
component. Higher response rates and greater resistance to change
occurred with the uncorrelated stimulus. These results highlight
the significance of considering the effects of an uncorrelated signal
when used as a control condition, and challenge accounts of resistance
to change that depend solely on reinforcer rate.
Key words: signaled reinforcement, response strength, resistance to
change, learning, lever press, rat