Runway performance of normal, sham, and anosmic rats as a function of magnitude of reward and magnitude shift

Abstract

A two-phase experiment was designed to yield information concerning the effects of magnitude of reward and magnitude shifts on the runway performance of normal, sham-operated, and surgically anosmic rats. Three squads of normal, sham, and anosmic subjects were each divided into three subgroups that received small, multiple-pellet large and single-pellet large reward, respectively, during the first phase (51 trials). During Phase II (30 trials), all subjects received the small reward. Reward magnitude effects developed during Phase I but were shown only by the normal and sham subjects. Significant depression effects were shown during Phase II by all subjects shifted from large to small reward. However, the form of the performance decrements shown during Phase II differed considerably between the normal and sham subjects and the anosmic subjects.