Frontostriatal functional connectivity supports reward-enhanced memory in older adults

Abstract

Both younger and older adults prioritize reward-associated stimuli in memory, but there has been little research on possible age differences in the neural mechanisms mediating this effect. In the present study, we examine neural activation and functional connectivity in healthy younger and older adults to test the hypothesis that older adults would engage prefrontal regions to a greater extent in the service of reward-enhanced memory. While undergoing MRI, target stimuli were presented after high- or low-reward cues. The cues indicated the reward value for successfully recognizing the stimulus on a memory test 24 hours later. We replicated prior findings that both older and younger adults had better memory for high- compared to low-reward stimuli. Critically, in older but not younger adults, this enhanced subsequent memory for high-reward items was supported by greater connectivity between the caudate and bilateral inferior frontal gyrus. The findings add to the growing literature on motivation-cognition interactions in healthy aging and provide novel findings of the neural underpinnings of reward-motivated encoding.