Incentive Relativity and the Specificity of Reward Expectations in Honey Bees

Abstract

Honey bees were trained in a proboscis extension response procedure on a high quality reward to one of two odors under one of two contexts and then on a lower quality reward under the alternative context to the alternative odor. The performance decrement induced by the reduced reward, revealed by comparisons with subjects trained continually on the lower reward, was independent of odor context combinations or the order of experience with stimuli. In a second experiment subjects were forward or backward conditioned to a high quality reward or fed unconditionally and then trained ona low reward in a novel context to a novel odor. The observed performance decrement depended only on exposure to the high quality reward. These results suggest that incentive contrast effects arise from a simple mechanism—the comparison of a current incentive with experienced incentives— that is effectively independent of cues that signal a reward.