Effects of Food-Reinforcer Primes During Acquisition of an Instrumental Running Response in Rats

Summary

Two instrumental runway studies with rats as Ss investigated the effects of pretrial feedings on the acquisition and performance of the running response. Experiment 1, using a within-Ss design (N = 9), found no difference in running times during acquisition in prefed and nonprefed alleys. During extinction there was a facilitation of running within each alley on prefed versus nonprefed trials, but again no between-alley differences. Experiment 2, using a between-groups design (N = 10), showed that prefeeding 30 sec prior to the trial decreased running times while prefeeding 300 sec prior increased running times at the start of training. Groups prefed 30 or 300 sec prior to these trials did not perform differently on nonprefed test trials. Thus, pretrial feedings do affect the performance, but not the strength of conditioning, of instrumental responses.