title: 'Language of the past' - Exploring past tense disruption during autobiographical narration in neurodegenerative disorders.
abstract: Compromised retrieval of autobiographical memory (ABM) is well established in neurodegenerative disorders. The recounting of autobiographical events is inextricably linked to linguistic knowledge, yet no study to date has investigated whether tense use during autobiographical narration is disrupted in dementia syndromes. This study investigated the incidence of correct past tense use during ABM narration in patients with Alzheimer's disease (AD, n = 10) and semantic dementia (SD, n = 10) in comparison with healthy older Controls (n = 10). Autobiographical narratives were analysed for episodic content (internal/external) and classified according to tense use (past/present). Across both patient groups, use of the past tense was significantly compromised relative to Controls, with increased levels of off-target present tense verbs observed. Voxel-based morphometry analyses based on structural MRI revealed differential associations between past tense use and regions of grey matter intensity in the brain. Bilateral temporal cortices were implicated in the SD group, whereas frontal, lateral, and medial temporal regions including the right hippocampus emerged in AD. This preliminary study provides the first demonstration of the disruption of specific linguistic constructs during autobiographical narration in AD and SD. Future studies are warranted to clarify at what point in the disease trajectory such deficits in tense use emerge, and whether these deficits are a product or contributing factor in memory disruption in these syndromes.
authors.affiliation: School of Psychology, The University of New South Wales, Sydney, Australia.|Neuroscience Research Australia, Randwick, Sydney, New South Wales, Australia.|Australian Research Council Centre of Excellence in Cognition and Its Disorders, Sydney, New South Wales, Australia.
authors.forename: Muireann
authors.initials: M
authors.lastname: Irish
authors.affiliation: School of Psychology, The University of New South Wales, Sydney, Australia.|Neuroscience Research Australia, Randwick, Sydney, New South Wales, Australia.
authors.forename: Jody
authors.initials: J
authors.lastname: Kamminga
authors.affiliation: School of Psychology and Centre for Brain Research, The University of Auckland, New Zealand.
authors.forename: Donna Rose
authors.initials: DR
authors.lastname: Addis
authors.affiliation: Australian Research Council Centre of Excellence in Cognition and Its Disorders, Sydney, New South Wales, Australia.|Department of Linguistics, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Crain
authors.affiliation: Australian Research Council Centre of Excellence in Cognition and Its Disorders, Sydney, New South Wales, Australia.|Department of Linguistics, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Rosalind
authors.initials: R
authors.lastname: Thornton
authors.affiliation: Neuroscience Research Australia, Randwick, Sydney, New South Wales, Australia.|Australian Research Council Centre of Excellence in Cognition and Its Disorders, Sydney, New South Wales, Australia.|School of Medical Sciences, The University of New South Wales, Sydney, Australia.
authors.forename: John R
authors.initials: JR
authors.lastname: Hodges
authors.affiliation: Neuroscience Research Australia, Randwick, Sydney, New South Wales, Australia.|Australian Research Council Centre of Excellence in Cognition and Its Disorders, Sydney, New South Wales, Australia.|School of Medical Sciences, The University of New South Wales, Sydney, Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Piguet
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001921:Brain / Q000000981:diagnostic imaging; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology*; D061212:Memory, Episodic; D008875:Middle Aged; D033262:Narration; D019636:Neurodegenerative Diseases / Q000150:complications* / Q000000981:diagnostic imaging; D009483:Neuropsychological Tests; D012660:Semantics
keywords: autobiographical memory; dementia; episodic memory; hippocampus; inferior frontal gyrus; language; semantic memory; temporal lobe