Face Short-Term Memory-Related Electroencephalographic Patterns can Differentiate Multi- versus Single-Domain Amnestic Mild Cognitive Impairment

Article type: Research Article

Authors: Deiber, Marie-Pierre^{a; b; *} | Ibáñez, Vicente^b | Herrmann, François^c | Rodriguez, Cristelle^d | Emch, Joan^d | Missonnier, Pascal^{b; d} | Millet, Philippe^b | Gold, Gabriel^c | Giannakopoulos, Panteleimon^{d; e}

Affiliations: [a] INSERM U1039, Faculty of Medicine, La Tronche, France | [b] Clinical Neurophysiology and Neuroimaging Unit, Division of Neuropsychiatry, Department of Psychiatry, University Hospitals of Geneva, Chêne-Bourg, Switzerland | [c] Department of Rehabilitation and Geriatrics, University Hospitals of Geneva, Geneva, Switzerland | [d] Division of Geriatric Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland | [e] Division of Old Age Psychiatry, University Hospitals of Lausanne, Lausanne, Switzerland

Correspondence: [*] Correspondence to: Marie-Pierre Deiber, Clinical Neurophysiology and Neuroimaging Unit, Division of Neuropsychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, 1225 Chêne-Bourg, Switzerland. Tel.: +41 22 305 53 82; Fax: +41 22 305 53 50; E-mail: Marie.P.DeiberIbanez@hcuge.ch.

Abstract: Amnestic mild cognitive impairment (aMCI) is characterized by memory deficits alone (single-domain, sd-aMCI) or associated with other cognitive disabilities (multi-domain, md-aMCI). The present study assessed the patterns of electroencephalographic (EEG) activity during the encoding and retrieval phases of short-term memory in these two aMCI subtypes, to identify potential functional differences according to the neuropsychological profile. Continuous EEG was recorded in 43 aMCI patients, whose 16 sd-aMCI and 27 md-aMCI, and 36 age-matched controls (EC) during delayed match-to-sample tasks for face and letter stimuli. At encoding, attended stimuli elicited parietal alpha (8–12 Hz) power decrease (desynchronization), whereas distracting stimuli were associated with alpha power increase (synchronization) over right central sites. No difference was observed in parietal alpha desynchronization among the three groups. For attended faces, the alpha synchronization underlying suppression of distracting letters was reduced in both aMCI subgroups, but more severely in md-aMCI cases that differed significantly from EC. At retrieval, the early N250r recognition effect was significantly reduced for faces in md-aMCI as compared to both sd-aMCI and EC. The results suggest a differential alteration of working memory cerebral processes for faces in the two aMCI subtypes, face covert recognition processes being specifically altered in md-aMCI.

Keywords: Alpha activity, amnestic MCI, EEG, face, N250r component, working memory

DOI: 10.3233/JAD-2011-110170

Journal: Journal of Alzheimer's Disease, vol. 26, no. 1, pp. 157-169, 2011