Learning in the Rat of a Choice Response by Observation of S-S Contingencies

This chapter describes a program of research that contributes to the analysis of the mechanisms mediating observational learning. ¹ The basic design is one in which a hungry rat observes two distinctive environmental events, one having a positive consequence (food pellet) and the other a negative consequence (no pellet). These events, downward movement of two radically different levers (bars), are ones that the rat, if so permitted, could bring about by itself. Initially, though, the bars are inaccessible and operated solely by a hidden experimenter. When the rat clearly indicates it has learned the unique correlation between the movement of the positive, or S+, bar and the availability of food, both bars are made accessible to the rat to determine whether it will make the S+ event happen. Unlike many other observational learning experiments this procedure ensures that the rat has observed the relevant environmental events because it must use these events to perform correctly on a go/no-go discrimination by approaching a distal food tray after the S+ bar has been activated and inhibit approach after the S- bar has been activated. Failure to make this critical check of the observing response may help explain the many failures to demonstrate imitative behavior from Thorndike (1898) on.