Response-reinforcer dependence and independence in multiple and mixed schedules.

Albino rats were conditioned to lever press during two-component multiple and mixed schedules in which response-dependent and response-independent reinforcers occurred in the different components. Relative response rates in the components associated with response-dependent reinforcers were higher (a) when different visual and auditory stimuli were associated with the two components and (b) when mixed schedule components were long in duration. These results illustrate the contribution of the response-reinforcer relation to stimulus control and schedule control of behavior. They also suggest that under some conditions, reinforcers need not be consistently associated with a particular response to ensure that the response is maintained at a relatively high rate.