title: Pauses During Autobiographical Discourse Reflect Episodic Memory Processes in Early Alzheimer's Disease.
abstract: There is a large body of research on discourse production in Alzheimer's disease (AD). Some studies have focused on pause production, revealing that patients make extensive use of pauses during speech. This has been attributed to lexical retrieval difficulties, but pausing may also reflect other forms of cognitive impairment as it increases with cognitive load. The aim of the present study was to analyze autobiographical discourse impairment in AD from a broad perspective, looking at pausing behavior (frequency, duration, and location). Our first objective was to characterize discourse changes in mild cognitive impairment (MCI) due to AD. Our second objective was to determine the cognitive and neuroanatomical correlates of these changes. Fifteen patients with MCI due to AD and 15 matched cognitively normal controls underwent an ecological episodic memory task, a full neuropsychological assessment, and a 3D T1-weighted MRI scans. Autobiographical discourse collected from the ecological episodic memory task was recorded, transcribed, and analyzed, focusing on pausing. Intergroup comparisons showed that although patients did not produce more pauses than controls overall, they did make more between-utterance pauses. The number of these specific pauses was positively correlated with patients' episodic memory performance. Furthermore, neuroimaging analysis showed that, in the patient group, their use was negatively correlated with frontopolar area (BA 10) grey matter density. This region may therefore play an important role in the planning of autobiographical discourse production. These findings demonstrate that pauses in early AD may reflect a compensatory mechanism for improving mental time travel and memory retrieval.
authors.affiliation: "Brain Imaging and Neurological Disabilities" joint research unit (UMR 825), INSERM, Toulouse University Hospital, Toulouse, France.|"Brain Imaging and Neurological Disabilities" joint research unit (UMR 825), University of Toulouse III - Paul Sabatier, Toulouse University Hospital, Toulouse, France.|Octogone-Lordat interdisciplinary research unit (EA 4156), University of Toulouse II - Jean Jaurès, Toulouse, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Pistono
authors.affiliation: Octogone-Lordat interdisciplinary research unit (EA 4156), University of Toulouse II - Jean Jaurès, Toulouse, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Jucla
authors.affiliation: Centre for Brain Research and Cognition (CerCo), CNRS - University of Toulouse III - Paul Sabatier, Toulouse, France.
authors.forename: Emmanuel J
authors.initials: EJ
authors.lastname: Barbeau
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Translational Alzheimer Neurobiology, Karolinska Institutet, Novum, Stockholm, Sweden.
authors.forename: Laure
authors.initials: L
authors.lastname: Saint-Aubert
authors.affiliation: Neurology Department, Neuroscience Centre, Toulouse University Hospital, Toulouse, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Lemesle
authors.affiliation: Adult and elder psychiatry Department, Limoges Hospital, Limoges, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Calvet
authors.affiliation: Octogone-Lordat interdisciplinary research unit (EA 4156), University of Toulouse II - Jean Jaurès, Toulouse, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: Köpke
authors.affiliation: "Brain Imaging and Neurological Disabilities" joint research unit (UMR 825), INSERM, Toulouse University Hospital, Toulouse, France.|"Brain Imaging and Neurological Disabilities" joint research unit (UMR 825), University of Toulouse III - Paul Sabatier, Toulouse University Hospital, Toulouse, France.|Neurology Department, Neuroscience Centre, Toulouse University Hospital, Toulouse, France.
authors.forename: Michèle
authors.initials: M
authors.lastname: Puel
authors.affiliation: "Brain Imaging and Neurological Disabilities" joint research unit (UMR 825), INSERM, Toulouse University Hospital, Toulouse, France.|"Brain Imaging and Neurological Disabilities" joint research unit (UMR 825), University of Toulouse III - Paul Sabatier, Toulouse University Hospital, Toulouse, France.|Neurology Department, Neuroscience Centre, Toulouse University Hospital, Toulouse, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Pariente
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D000682:Amyloid / Q000134:cerebrospinal fluid; D001921:Brain / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D061212:Memory, Episodic; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D013223:Statistics as Topic
chemical_list: D000682:Amyloid
keywords: Episodic memory; language; mild cognitive impairment; natural language processing; neuroimaging