title: Overlapping effects of age on associative memory and the anterior hippocampus from middle to older age.
abstract: The anterior hippocampus has been implicated in associative memory, and along with hippocampal volume, this type of memory declines with age. However, few cross-sectional studies include middle-aged samples, making it unclear at what point these age-related changes occur. In addition, although men and women have been shown to differ in associative memory and rates of age-related hippocampal atrophy, sex-differences in aging are rarely studied. To address these issues, we assessed memory for word-pairs, hippocampal volume and activation during encoding and retrieval, across middle-aged (n=39) and older (n=44) participants, specifically in relation to sex. Older adults showed significantly poorer associative memory compared to middle-aged adults, paralleled by smaller anterior hippocampi and less activation during successful retrieval. The age-by-sex interaction observed in memory performance was also mirrored in the volume and activation of the hippocampus, indicating more pronounced age-effects in men as compared to women. These results indicate a specific role of the anterior hippocampus in verbal associative memory and suggest they both decline between middle-age and older age.
authors.affiliation: Department of Psychology, Uppsala University, Box 1225, 751 42 Uppsala, Sweden. Electronic address: kristin.nordin@psyk.uu.se.
authors.forename: Kristin
authors.initials: K
authors.lastname: Nordin
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Nobels Väg 9, 171 77 Stockholm, Sweden. Electronic address: agneta.herlitz@ki.se.
authors.forename: Agneta
authors.initials: A
authors.lastname: Herlitz
authors.affiliation: Department of Surgical Sciences, Radiology, Uppsala University, Uppsala University Hospital, 751 85 Uppsala, Sweden. Electronic address: elna-marie.larsson@radiol.uu.se.
authors.forename: Elna-Marie
authors.initials: EM
authors.lastname: Larsson
authors.affiliation: Department of Psychology, Uppsala University, Box 1225, 751 42 Uppsala, Sweden. Electronic address: hedvig.soderlund@psyk.uu.se.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Söderlund
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001245:Association Learning / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D012737:Sex Factors; D013223:Statistics as Topic
chemical_list: D010100:Oxygen
keywords: Aging; Episodic memory; Event-related activation; Sex; Voxel-based morphometry; fMRI