Discrete-trial instrumental performance related to reward schedule and developmental level.

Abstract

120 5"s at each of 6 developmental levels performed an instrumental lever-pulling task. 6 reward groups (0%, 10%, 30%, 50%, 70%, 100%) were formed within each age level and measures of response speed were taken. The typical finding of faster response speeds for partially as compared with continuously rewarded groups was not evident across all ages. Furthermore, some partial reward schedules other than 50% also lead to more vigorous responding as compared with 100% reward. In terms of frustration theory, it was suggested that desire to win and problem-solving strategies employed at different age levels, as well as expectancy for reward, may all play important roles in determining reaction to nonreward.