title: fMRI subsequent source memory effects in young, middle-aged and old adults.
abstract: The ability to remember the spatial context in which our experiences occur declines linearly across the adult lifespan. However, little is known about whether this source memory decline is associated with neural activity changes. In the present study, functional magnetic resonance imaging (fMRI) scans were recorded in young, middle-aged and old adults to investigate brain activity variations across the adult lifespan during encoding of subsequent spatial source memory retrieval. Twelve healthy individuals of both sexes were enrolled in each age group. During encoding, participants performed natural/artificial judgment of images of common objects that were randomly presented in one of the quadrants of the screen. During retrieval, the images presented at encoding were randomly mixed with new ones and displayed at the center of the screen. Participants judged whether each image was new or old and, if an image was old, they were instructed to indicate in which quadrant the image was presented in the encoding session. The contrast between study items that were later recognized and assigned a correct source judgment with those whose sources were subsequently forgotten revealed that positive subsequent memory effects disappear by middle age in the left medial orbitofrontal gyrus and appear in the left superior occipital gyrus. This under-recruitment and over-recruitment brain activity was also present in old adults. The results allowed us to identify the specific brain regions that first fail to encode spatial information into an episodic representation during the adult lifespan.
authors.affiliation: Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico. Electronic address: selene@unam.mx.
authors.forename: Selene
authors.initials: S
authors.lastname: Cansino
authors.affiliation: Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico.
authors.forename: Cinthya
authors.initials: C
authors.lastname: Estrada-Manilla
authors.affiliation: Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Trejo-Morales
authors.affiliation: Institute of Neurobiology, National Autonomous University of Mexico, Querétaro, Mexico.
authors.forename: Erick Humberto
authors.initials: EH
authors.lastname: Pasaye-Alcaraz
authors.affiliation: Cognition and Behavior Unity, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
authors.forename: Erika
authors.initials: E
authors.lastname: Aguilar-Castañeda
authors.affiliation: Department of Neuroimaging, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
authors.forename: Perla
authors.initials: P
authors.lastname: Salgado-Lujambio
authors.affiliation: Laboratory of Dementias, National Institute of Neurology and Neurosurgery, Mexico City, Mexico.
authors.forename: Ana Luisa
authors.initials: AL
authors.lastname: Sosa-Ortiz
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007600:Judgment / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D055815:Young Adult
keywords: Aging; Episodic memory; Functional magnetic resonance imaging; Source memory; Subsequent memory effect