How age and culture impact the neural correlates of memory retrieval.

Culture can shape memory, but little research has investigated age effects. The present study examined the neural correlates of memory retrieval for old, new, and similar lures in younger and older Americans and Taiwanese. A total of 207 participants encoded pictures of objects and, during fMRI scanning, completed a surprise object recognition task testing discrimination of similar and new from old items. Results show that age and culture impact discrimination of old from new items. Taiwanese performed worse than Americans, with age effects more pronounced for Taiwanese. The cultural differences in the engagement of left inferior frontal gyrus (LIFG) in younger adults (i.e., greater activity for old [for Taiwanese] or new items [for Americans]) were eliminated with age. The results are interpreted as reflecting cultural differences in orientation to novelty versus familiarity for younger, but not older, adults, with the LIFG supporting interference resolution at retrieval. Support is not as strong for cultural differences in pattern separation processes. Although Americans had higher levels of memory discrimination than Taiwanese, neither cultural nor age differences were found in hippocampal activity, which is surprising given the region's role in pattern separation. The findings suggest ways in which cultural life experiences and concomitant information processing strategies can contribute to consistent effects of age across cultures or contribute to different trajectories with age in terms of memory.