title: Behavioral and Electrophysiological Correlates of Memory Binding Deficits in Patients at Different Risk Levels for Alzheimer's Disease.
abstract: Deficits in visual short-term memory (VSTM) binding have been proposed as an early and specific marker for Alzheimer's disease (AD). However, no studies have explored the neural correlates of this domain in clinical categories involving prodromal stages with different risk levels of conversion to AD. We assessed underlying electrophysiological modulations in patients with mild cognitive impairment (MCI), patients in the MCI stages of familial AD carrying the mutation E280A of the presenilin-1 gene (MCI-FAD), and healthy controls. Moreover, we compared the behavioral performance and neural correlates of both patient groups. Participants completed a change-detection VSTM task assessing recognition of changes between shapes or shape-color bindings, presented in two consecutive arrays (i.e., study and test) while event related potentials (ERPs) were recorded. Changes always occurred in the test array and consisted of new features replacing studied features (shape-only) or features swapping across items (shape-color binding). Both MCI and MCI-FAD patients performed worse than controls in the shape-color binding condition. Early electrophysiological activity (100-250 ms) was significantly reduced in both clinical groups, particularly over fronto-central and parieto-occipital regions. However, shape-color binding performance and their reduced neural correlates were similar between MCI and MCI-FAD. Our results support the validity of the VSTM binding test and their neural correlates in the early detection of AD and highlight the importance of studies comparing samples at different risk for AD conversion. The combined analysis of behavioral and ERP data gleaned with the VSTM binding task can offer a valuable memory biomarker for AD.
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.|Unidad de Neurobiología Aplicada, Centro de Educación Médica e Investigaciones Clínicas Norberto Quirno (CEMIC), Consejo Nacional de Investigaciones Científicas y Técnicas CONICET, Buenos Aires, Argentina.
authors.forename: Marcos
authors.initials: M
authors.lastname: Pietto
authors.affiliation: School of Life Sciences, Psychology, Heriot-Watt University, UK.|Human Cognitive Neuroscience and Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, UK.|Alzheimer Scotland Dementia Research Centre and Scottish Dementia Clinical Research Network, UK.|Universidad Autónoma del Caribe, Barranquilla, Colombia.
authors.forename: Mario A
authors.initials: MA
authors.lastname: Parra
authors.affiliation: School of Public Health, University of Antioquia (UDEA), Medellin, Colombia.|Neuroscience Group, Faculty of Medicine, University of Antioquia (UDEA), Medellin.
authors.forename: Natalia
authors.initials: N
authors.lastname: Trujillo
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
authors.forename: Facundo
authors.initials: F
authors.lastname: Flores
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.|ACR Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, Australia.
authors.forename: Adolfo M
authors.initials: AM
authors.lastname: García
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
authors.forename: Julian
authors.initials: J
authors.lastname: Bustin
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
authors.forename: Pablo
authors.initials: P
authors.lastname: Richly
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.|Faculty of Elementary and Special Education (FEEyE), National University of Cuyo (UNCuyo), Sobremonte 74, C5500, Mendoza, Argentina.
authors.forename: Facundo
authors.initials: F
authors.lastname: Manes
authors.affiliation: Neuroscience Group, Faculty of Medicine, University of Antioquia (UDEA), Medellin.
authors.forename: Francisco
authors.initials: F
authors.lastname: Lopera
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.|Universidad Autónoma del Caribe, Barranquilla, Colombia.|Faculty of Elementary and Special Education (FEEyE), National University of Cuyo (UNCuyo), Sobremonte 74, C5500, Mendoza, Argentina.
authors.forename: Agustín
authors.initials: A
authors.lastname: Ibáñez
authors.affiliation: Instituto de Neurociencia Cognitiva y Traslacional (INCyT), Laboratorio de Psicología Experimental y Neurociencias (LPEN), Fundación INECO, Universidad de Favaloro, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.|Grupo de Investigación Cerebro y Cognición Social, Bogotá, Colombia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Baez
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000235:genetics* / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology*; D060825:Cognitive Dysfunction / Q000235:genetics / Q000503:physiopathology*; D003118:Color Perception / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006801:Humans; D008569:Memory Disorders / Q000235:genetics / Q000503:physiopathology*; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D053764:Presenilin-1 / Q000235:genetics; D062706:Prodromal Symptoms; D012306:Risk
chemical_list: C508853:PSEN1 protein, human; D053764:Presenilin-1
keywords: Electroencephalogram (EEG); event related potentials (ERPs); familial Alzheimer’s disease; memory binding; mild cognitive impairment; short-term memory