title: Differences between mild cognitive impairment subtypes as indicated by event-related potential correlates of cognitive and motor processes in a Simon task.
abstract: Mild cognitive impairment (MCI) may represent a prodromal stage of Alzheimer's disease (AD), although the clinical manifestations of MCI are heterogeneous. Consequently, MCI subtypes are differentiated since amnestic decline (particularly when combined with decline on multiple cognitive domains) increases the probability of progression to AD. In the present study, event-related potential (ERP) correlates of stimulus evaluation (N2), visuospatial attention (negativity posterior-contralateral, N2pc), stimulus categorization (P3b), executive control (pre-response positivity, PP, and medial frontal negativity), and motor (lateralized readiness potential, LRP) processes were studied in 53 participants while they performed a Simon task. Participants were divided into control group (CG), multiple-domain non-amnestic MCI (mdnaMCI), single-domain amnestic MCI (sdaMCI), and multiple-domain amnesic MCI (mdaMCI). Although there were no differences in reaction times and percentage of errors in the performed Simon-type task, a differential pattern of electrophysiological correlates was observed in MCI compared to CG. Concretely, amnestic MCI (sdaMCI and mdaMCI) showed reduced motor activity (LRP amplitude; AUC: 0.84); impairment in executive control (PP amplitude; AUC: 0.80) was observed in multiple-domain MCI (mdaMCI and mdnaMCI); finally, stimulus evaluation (N2 latency; AUC: 0.86) and visuospatial attention (N2pc amplitude; AUC: 0.78) was affected in mdaMCI. Overall, results linked the poorer prognosis of the mdaMCI subtype with a greater number of differences in ERP correlates regarding CG. Therefore, the present results enable us to suggest possible ERP biomarkers for specific MCI subtypes.
authors.affiliation: Laboratorio de Neurociencia Cognitiva, Departamento de Psicoloxía Clínica e Psicobioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Cespón
authors.affiliation: Laboratorio de Neurociencia Cognitiva, Departamento de Psicoloxía Clínica e Psicobioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Galdo-Álvarez
authors.affiliation: Departamento de Psicoloxía Evolutiva e da Educación, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
authors.forename: Arturo X
authors.initials: AX
authors.lastname: Pereiro
authors.affiliation: Laboratorio de Neurociencia Cognitiva, Departamento de Psicoloxía Clínica e Psicobioloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Díaz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000145:classification* / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D056344:Executive Function / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000209:etiology; D011597:Psychomotor Performance / Q000502:physiology; D012372:ROC Curve; D011930:Reaction Time / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
keywords: Central nervous system diseases; mental processes; neurodegenerative diseases; psychophysiology