title: Event-related functional magnetic resonance imaging changes during relational retrieval in normal aging and amnestic mild cognitive impairment.
abstract: The earliest cognitive deficits observed in amnestic mild cognitive impairment (aMCI) appear to center on memory tasks that require relational memory (RM), the ability to link or integrate unrelated pieces of information. RM impairments in aMCI likely reflect neural changes in the medial temporal lobe (MTL) and posterior parietal cortex (PPC). We tested the hypothesis that individuals with aMCI, as compared to cognitively normal (CN) controls, would recruit neural regions outside of the MTL and PPC to support relational memory. To this end, we directly compared the neural underpinnings of successful relational retrieval in aMCI and CN groups, using event-related functional magnetic resonance imaging (fMRI), holding constant the stimuli and encoding task. The fMRI data showed that the CN, compared to the aMCI, group activated left precuneus, left angular gyrus, right posterior cingulate, and right parahippocampal cortex during relational retrieval, while the aMCI group, relative to the CN group, activated superior temporal gyrus and supramarginal gyrus for this comparison. Such findings indicate an early shift in the functional neural architecture of relational retrieval in aMCI, and may prove useful in future studies aimed at capitalizing on functionally intact neural regions as targets for treatment and slowing of the disease course. (JINS, 2012, 18, 1-12).
authors.affiliation: Department of Psychology, The University of North Carolina, Chapel Hill, North Carolina 27713, USA. kgio@unc.edu
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Giovanello
authors.forename: Felipe
authors.initials: F
authors.lastname: De Brigard
authors.forename: Jaclyn
authors.initials: J
authors.lastname: Hennessey Ford
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Kaufer
authors.forename: James R
authors.initials: JR
authors.lastname: Burke
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Browndyke
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Welsh-Bohmer
mesh_terms: D000368:Aged; D000375:Aging; D000647:Amnesia / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply* / Q000473:pathology; D060825:Cognitive Dysfunction / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology; D009483:Neuropsychological Tests