title: Gamma oscillatory activity is impaired in episodic memory encoding with age.
abstract: The present study proposes to investigate age-related episodic memory impairment in encoding. We collected ERPs in young and old participants performing a word-encoding task. For subsequently remembered words, young adults had greater activity at the left and anterior electrode sites, whereas old adults had greater posterior activity. Performance correlated positively with central sites in young adults but with left parietal hemisphere activity in old adults. Plus, a large left frontoparietal network increased its activity during the successful encoding for the Beta (13-30 Hz) and Gamma (30-100 Hz) bands in young adults. Old adults had increased activity in the right posterior parietal region for forgotten words in the Gamma band. Using a source localization analysis, we found that age leads to a decrease in Gamma band cerebral activity during encoding of words in the left hemisphere and the bilateral parahippocampal regions. These findings indicate that encoding impairment with age may be associated with dysfunctional Gamma oscillatory activity across a widespread network of left cortical regions.
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UNISTRA), Strasbourg, France. Electronic address: o.despres@unistra.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Després
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UNISTRA), Strasbourg, France.
authors.forename: Ségolène
authors.initials: S
authors.lastname: Lithfous
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UNISTRA), Strasbourg, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Tromp
authors.affiliation: Centre d'Investigations Neurocognitives et Neurophysiologiques (CI2N - UMS 3489 - CNRS/UNISTRA), Strasbourg, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Pebayle
authors.affiliation: Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UNISTRA), Strasbourg, France; Centre d'Investigations Neurocognitives et Neurophysiologiques (CI2N - UMS 3489 - CNRS/UNISTRA), Strasbourg, France.
authors.forename: André
authors.initials: A
authors.lastname: Dufour
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D004569:Electroencephalography; D005260:Female; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000502:physiology; D055815:Young Adult
keywords: Aging; Dm effect; EEG; Encoding; Episodic memory; Source localization