title: An fMRI study of episodic encoding across the lifespan: changes in subsequent memory effects are evident by middle-age.
abstract: Although it is well-documented that there are age differences between young and older adults in neural activity associated with successful memory formation (positive subsequent memory effects), little is known about how this activation differs across the lifespan, as few studies have included middle-aged adults. The present study investigated the effect of age on neural activity during episodic encoding using a cross-sectional lifespan sample (20-79 years old, N=192) from the Dallas Lifespan Brain Study. We report four major findings. First, in a contrast of remembered vs. forgotten items, a decrease in neural activity occurred with age in bilateral occipito-temporo-parietal regions. Second, when we contrasted forgotten with remembered items (negative subsequent memory), the primary difference was found between middle and older ages. Third, there was evidence for age equivalence in hippocampal regions, congruent with previous studies. Finally, low-memory-performers showed negative subsequent memory differences by middle age, whereas high memory performers did not demonstrate these differences until older age. Taken together, these findings delineate the importance of a lifespan approach to understanding neurocognitive aging and, in particular, the importance of a middle-age sample in revealing different trajectories.
authors.affiliation: Department of Psychology, College of Science, University of Texas at Arlington, 501S Nedderman Dr, Arlington, TX 76019, USA. hkpark@uta.edu
authors.forename: Heekyeong
authors.initials: H
authors.lastname: Park
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Kennedy
authors.forename: Karen M
authors.initials: KM
authors.lastname: Rodrigue
authors.forename: Andrew
authors.initials: A
authors.lastname: Hebrank
authors.forename: Denise C
authors.initials: DC
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D055815:Young Adult
chemical_list: D010100:Oxygen