Age differences in neural pattern similarity associated with false recognition
Caitlin Bowman1, Christina Webb2, Jordan Chamberlain2, Nancy Dennis2; 1University of Oregon, 2The Pennsylvania State University
Older adults are more likely than young to endorse new information as old when it shares features with studied information. Such age-related increases in false recognition may be related to age differences in how retrieval lures elicit reactivation of information from study. Such reactivation may promote lure rejection by helping to detect mismatch between targets and lures, or it may promote false recognition when reactivated representations lack details necessary to make these distinctions. We used an encoding-retrieval pattern similarity analysis in young and older adults to compare the overlap in neural representations between retrieval lures and their respective targets at encoding, and then linked these similarity patterns to false recognition and correct rejection responses. Across age groups, we found greater encoding-retrieval similarity for targets and lures compared to completely new items in inferior frontal gyrus, middle temporal gyrus, and several visual regions. Within these regions, pattern similarity between lures and studied information tracked false recognition in inferotemporal cortex and middle temporal gyrus in both age groups, suggesting that memory representations in these regions lack the specificity necessary to distinguish between targets and related lures. We also identified age differences in lateral occipital cortex, where only young adults showed differences in target-lure pattern similarity based on how strongly the lure resembled the target. Representations in this region were linked to both target recollection and lure rejection, indicating that aging reduces reactivation of visual details from encoding that facilitate lure rejection, contributing to increased false recognition.
Topic Area: LONG-TERM MEMORY: Episodic