title: The Role of Medial Temporal Lobe Regions in Incidental and Intentional Retrieval of Item and Relational Information in Aging.
abstract: Considerable neuropsychological and neuroimaging work indicates that the medial temporal lobes are critical for both item and relational memory retrieval. However, there remain outstanding issues in the literature, namely the extent to which medial temporal lobe regions are differentially recruited during incidental and intentional retrieval of item and relational information, and the extent to which aging may affect these neural substrates. The current fMRI study sought to address these questions; participants incidentally encoded word pairs embedded in sentences and incidental item and relational retrieval were assessed through speeded reading of intact, rearranged, and new word-pair sentences, while intentional item and relational retrieval were assessed through old/new associative recognition of a separate set of intact, rearranged, and new word pairs. Results indicated that, in both younger and older adults, anterior hippocampus and perirhinal cortex indexed incidental and intentional item retrieval in the same manner. In contrast, posterior hippocampus supported incidental and intentional relational retrieval in both age groups and an adjacent cluster in posterior hippocampus was recruited during both forms of relational retrieval for older, but not younger, adults. Our findings suggest that while medial temporal lobe regions do not differentiate between incidental and intentional forms of retrieval, there are distinct roles for anterior and posterior medial temporal lobe regions during retrieval of item and relational information, respectively, and further indicate that posterior regions may, under certain conditions, be over-recruited in healthy aging. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Center for Cognitive Neuroscience, Duke University, Durham, North Carolina.
authors.forename: Wei-Chun
authors.identifier: 0000-0003-1788-2727
authors.initials: WC
authors.lastname: Wang
authors.affiliation: Department of Psychology and Biomedical Research Imaging Center, The University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Giovanello
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D000704:Analysis of Variance; D001244:Association; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time; D011932:Reading; D021641:Recognition, Psychology / Q000502:physiology*; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000502:physiology*; D055815:Young Adult
keywords: aging; hippocampus; item memory; perirhinal cortex; relational memory