Age-related declines in the fidelity of newly acquired category representations

Department of Cognitive, Perceptual, and Brain Sciences, University College London, London WC1E 6BT, United KingdomWepresent a theorysuggesting that the ability to build category representations that reflect the nuances of category struc-tures in the environment depends upon clustering mechanisms instantiated in an MTL-PFC-based circuit. Because functioninthis circuitdeclineswithage,wepredictthattheabilitytobuildcategory representations willbeimpairedinolderadults.Consistent with this prediction, we find that older adults are impaired relative to younger adults at learning nuanced cat-egory structures that contain exceptions to the rule. Model-based analysis reveals that this deficit arises from older adults’failure to engage clustering mechanisms to separate exception and rule-following items in memory.[Supplemental material is available for this article.]