title: Age-related individual variability in memory performance is associated with amygdala-hippocampal circuit function and emotional pattern separation.
abstract: While aging is generally associated with episodic memory decline, not all older adults exhibit memory loss. Furthermore, emotional memories are not subject to the same extent of forgetting and appear preserved in aging. We conducted high-resolution fMRI during a task involving pattern separation of emotional information in older adults with and without age-related memory impairment (characterized by performance on a word-list learning task: low performers: LP vs. high performers: HP). We found signals consistent with emotional pattern separation in hippocampal dentate (DG)/CA3 in HP but not in LP individuals, suggesting a deficit in emotional pattern separation. During false recognition, we found increased DG/CA3 activity in LP individuals, suggesting that hyperactivity may be associated with overgeneralization. We additionally observed a selective deficit in basolateral amygdala-lateral entorhinal cortex-DG/CA3 functional connectivity in LP individuals during pattern separation of negative information. During negative false recognition, LP individuals showed increased medial temporal lobe functional connectivity, consistent with overgeneralization. Overall, these results suggest a novel mechanistic account of individual differences in emotional memory alterations exhibited in aging.
authors.affiliation: Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA; Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Leal
authors.affiliation: Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Noche
authors.affiliation: Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Murray
authors.affiliation: Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA. Electronic address: myassa@uci.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Yassa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology* / Q000523:psychology*; D000679:Amygdala / Q000000981:diagnostic imaging / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*
keywords: Aging; Amygdala; Emotion; Hippocampus; Lateral entorhinal cortex; Memory