| Abstract | In typical feature-positive discriminations, responding is reinforced during the target stimulus on trials with the feature stimulus (XA+), but not during target alone trials (A-). In the current studies, one response (e.g., left lever press) was reinforced during feature-target trials (XA+) and a different response (e.g., right lever press) was reinforced during target alone trials (A+). In Experiment 1, rats received either serial (X¿ A+), or simultaneous (X:A+) presentations of the feature-target compound. Both groups also received A alone trials (A+). Experiment 2 included an additional Serial group, with an extended interval between the stimuli. Following training in both experiments, responding to presentations of X-, XA-, and A- was examined before and after extinction of X. Experiment 1 results suggest that direct control by X occurred in both groups. Experiment 2 results suggest that in both Serial groups, X controlled responding, but in the Simultaneous group, occasion setting-like behavior occurred. |
