title: The self-reference effect in dementia: Differential involvement of cortical midline structures in Alzheimer's disease and behavioural-variant frontotemporal dementia.
abstract: Encoding information in reference to the self enhances subsequent memory for the source of this information. In healthy adults, self-referential processing has been proposed to be mediated by the cortical midline structures (CMS), with functional differentiation between anterior-ventral, anterior-dorsal and posterior regions. While both Alzheimer's disease (AD) and behavioural-variant frontotemporal dementia (bvFTD) patients show source memory impairment, it remains unclear whether they show a typical memory advantage for self-referenced materials. We also sought to identify the neural correlates of this so-called 'self-reference effect' (SRE) in these patient groups. The SRE paradigm was tested in AD (n = 16) and bvFTD (n = 22) patients and age-matched healthy controls (n = 17). In this task, participants studied pictures of common objects paired with one of two background scenes (sources) under self-reference or other-reference encoding instructions, followed by an item and source recognition memory test. Voxel-based morphometry was used to investigate correlations between SRE measures and regions of grey matter atrophy in the CMS. The behavioural results indicated that self-referential encoding did not ameliorate the significant source memory impairments in AD and bvFTD patients. Furthermore, the reduced benefit of self-referential relative to other-referential encoding was not related to general episodic memory deficits. Our imaging findings revealed that reductions in the SRE were associated with atrophy in the anterior-dorsal CMS across both patient groups, with additional involvement of the posterior CMS in AD and anterior-ventral CMS in bvFTD. These findings suggest that although the SRE is comparably reduced in AD and bvFTD, this arises due to impairments in different subcomponents of self-referential processing.
authors: ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Department of Psychology, Macquarie University, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia.
authors: Stephanie
authors: S
authors: Wong
authors: ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia; School of Psychology, The University of New South Wales, Sydney, Australia.
authors: Muireann
authors: M
authors: Irish
authors: Department of Psychology, University of Illinois at Chicago, Chicago, IL, USA.
authors: Eric D
authors: ED
authors: Leshikar
authors: School of Psychology, Georgia Institute of Technology, Atlanta, GA, USA.
authors: Audrey
authors: A
authors: Duarte
authors: Norwich Medical School, University of East Anglia, Norwich, UK.
authors: Maxime
authors: M
authors: Bertoux
authors: ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Department of Psychology, Macquarie University, Sydney, Australia.
authors: Greg
authors: G
authors: Savage
authors: ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia; School of Medical Sciences, The University of New South Wales, Sydney, Australia.
authors: John R
authors: JR
authors: Hodges
authors: ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia; School of Medical Sciences, The University of New South Wales, Sydney, Australia.
authors: Olivier
authors: O
authors: Piguet
authors: ARC Centre of Excellence in Cognition and its Disorders, Sydney, Australia; Norwich Medical School, University of East Anglia, Norwich, UK. Electronic address: m.hornberger@uea.ac.uk.
authors: Michael
authors: M
authors: Hornberger
mesh_terms: D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D001284:Atrophy / Q000150:complications; D001519:Behavior / Q000502:physiology; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D005260:Female; D057180:Frontotemporal Dementia / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008569:Memory Disorders / Q000150:complications*; D061212:Memory, Episodic; D008875:Middle Aged
keywords: Alzheimer's disease; Behavioural-variant frontotemporal dementia; Self-reference effect; Source memory; Voxel-based morphometry