Abstract
Long-term memory is sensitive to both intrinsic and extrinsic motivation, but little is known about the relative influence of these two sources of motivation on memory performance across the adult lifespan. The study examined the effects of extrinsic motivation, manipulated via monetary reward, and curiosity, a form of intrinsic motivation, on long-term memory in healthy younger and older adults. During the incidental encoding phase on Day 1, 60 younger and 53 older participants viewed high- and low-curiosity trivia items as well as unrelated face stimuli. Half of the participants in each age group received financial rewards for correctly guessing trivia answers. On Day 2, participants completed a trivia recall test and an old-new recognition test for the face stimuli. Both curiosity and reward were associated with enhanced trivia recall, but the effects were interactive, such that only low-curiosity items benefitted from monetary reward. Neither curiosity nor reward affected face recognition performance in either age group. These findings indicate that individual and joint effects of intrinsic and extrinsic motivation on long-term memory are relatively preserved in healthy aging, a finding that highlights the viability of motivational strategies for memory enhancement into old age. Identifying conditions under which memory for unrelated information benefits from motivational spillover effects in younger and older adults is a priority for future research.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Author Note: Findings from this study were presented at the CSBBCS 29th Annual Meeting (June, 2019) and the Cognitive Neuroscience Society 2020 Virtual Conference (May, 2020). This work was supported by the Canada Research Chairs Program (#950-232332 to J. S.). We gratefully acknowledge Carson Pun for his assistance with computer programming and Yazan Shamli-Oghli for his assistance with data collection. Task programs, data and analysis files are available from the corresponding author via email upon request. This study was not pre-registered.