ROLE OF EFFORT IN PERFORMANCE OF OBSERVING RESPONSES

The role of effort in performing observing responses in an E-Maze was studied in 32 rats and 4 pigeons. In Phase I of Exp. 1, rats' performa nce of observing responses was tested in a regular E-Maze condition an d in an extra-length condition in which the predictable arm of the E-M aze was 22 in. or 44 in. longer than the unpredictable arm of the E-Ma ze. The rats in the regular E-Maze condition preferred the predictable arm on free-choice trails, while those in the extra-length condition preferred the unpredictable, shorter side. In Phase 2 of Exp. 1, the r ats in the regular E-Maze condition were switched to an extra-length c ondition, and rats in the extra-length condition were switched to a re gular E-Maze condition. When these experimental conditions were revers ed, the choice behavior of the subjects in the two groups also reverse d. In Exp. 2, pigeons' performance of the observing response was teste d in an E-Maze. Four pigeons learned to perform the observing response in a regular E-Maze condition. They were then changed to an extra-len gth condition. Preference for the predictable side declined after the change. The results of these experiments show that, when extra effort is required to gain access to the discriminative stimuli, subjects do not perform an observing response.