title: Abnormal-induced theta activity supports early directed-attention network deficits in progressive MCI.
abstract: The electroencephalography (EEG) theta frequency band reacts to memory and selective attention paradigms. Global theta oscillatory activity includes a posterior phase-locked component related to stimulus processing and a frontal-induced component modulated by directed attention. To investigate the presence of early deficits in the directed attention-related network in elderly individuals with mild cognitive impairment (MCI), time-frequency analysis at baseline was used to assess global and induced theta oscillatory activity (4-6Hz) during n-back working memory tasks in 29 individuals with MCI and 24 elderly controls (EC). At 1-year follow-up, 13 MCI patients were still stable and 16 had progressed. Baseline task performance was similar in stable and progressive MCI cases. Induced theta activity at baseline was significantly reduced in progressive MCI as compared to EC and stable MCI in all n-back tasks, which were similar in terms of directed attention requirements. While performance is maintained, the decrease of induced theta activity suggests early deficits in the directed-attention network in progressive MCI, whereas this network is functionally preserved in stable MCI.
authors.affiliation: Department of Psychiatry, University Hospitals of Geneva, Switzerland. Marie.P.DeiberIbanez@hcuge.ch
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Deiber
authors.forename: Vicente
authors.initials: V
authors.lastname: Ibañez
authors.forename: Pascal
authors.initials: P
authors.lastname: Missonnier
authors.forename: François
authors.initials: F
authors.lastname: Herrmann
authors.forename: Lara
authors.initials: L
authors.lastname: Fazio-Costa
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gold
authors.forename: Panteleimon
authors.initials: P
authors.lastname: Giannakopoulos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D001288:Attention / Q000502:physiology*; D015415:Biomarkers; D002540:Cerebral Cortex / Q000503:physiopathology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology*; D018450:Disease Progression; D042241:Early Diagnosis; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013826:Theta Rhythm; D013997:Time Factors
chemical_list: D015415:Biomarkers