title: Age differences in brain activity related to unsuccessful declarative memory retrieval.
abstract: Although memory recall is known to be reduced with normal aging, little is known about the patterns of brain activity that accompany these recall failures. By assessing faulty memory, we can identify the brain regions engaged during retrieval attempts in the absence of successful memory and determine the impact of aging on this functional activity. We used functional magnetic resonance imaging to examine age differences in brain activity associated with memory failure in three memory retrieval tasks: autobiographical (AM), episodic (EM) and semantic (SM). Compared to successful memory retrieval, both age groups showed more activity when they failed to recall a memory in regions consistent with the salience network (SLN), a brain network also associated with non-memory errors. Both groups also showed strong functional coupling among SLN regions during incorrect trials and in intrinsic patterns of functional connectivity. In comparison to young adults, older adults demonstrated (1) less activity within the SLN during unsuccessful AM trials; (2) weaker intrinsic functional connectivity between SLN nodes and dorsolateral prefrontal cortex; and (3) less differentiation of SLN functional connectivity during incorrect trials across memory conditions. These results suggest that the SLN is engaged during recall failures, as it is for non-memory errors, which may be because errors in general have particular salience for adapting behavior. In older adults, the dedifferentiation of functional connectivity within the SLN across memory conditions and the reduction of functional coupling between it and prefrontal cortex may indicate poorer inter-network communication and less flexible use of cognitive control processes, either while retrieval is attempted or when monitoring takes place after retrieval has failed. This article is part of a Special Issue entitled SI: Memory & Aging.
authors.affiliation: Rotman Research Institute at Baycrest, 3560 Bathurst St, Toronto, Ontario, Canada M6A2E1; Departments of Psychiatry and Psychology, University of Toronto, Ontario, Canada M5S 3G3. Electronic address: cgrady@research.baycrest.org.
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Grady
authors.affiliation: Rotman Research Institute at Baycrest, 3560 Bathurst St, Toronto, Ontario, Canada M6A2E1.
authors.forename: Marie
authors.initials: M
authors.lastname: St-Laurent
authors.affiliation: Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland 4072, Australia.
authors.forename: Hana
authors.initials: H
authors.lastname: Burianová
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D000704:Analysis of Variance; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011930:Reaction Time; D012660:Semantics; D013997:Time Factors; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Aging; Episodic memory; Frontal lobe; Salience network; fMRI