Disorders of the Nervous System
Author: Franco Javier Ferrante | email: francoferrante95@gmail.com
Franco J. Ferrante1°2°3, Joaquín A. Migeot4°5°, Agustina Birba1°2°, Gonzalo Pérez1°2°, Eugenia Hesse6°, Enzo Tagliazucchi4°7°, Claudio Estienne8°, Cecilia Serrano9°, Andrea Slachevsky10°11°12°13°, Diana Matallana14°15°, Pablo Reyes16°17°, Agustín Ibañez1°2°4°18°, Sol Fittipaldi1°2°, Cecilia Gonzalez Campo1°2°, Adolfo M. García1°2°18°20°
1° Centro de Neurociencias Cognitivas Universidad de San Andrés, Buenos Aires, Argentina 2° National Scientific and Technical Research Council (CONICET) Buenos Aires, Argentina 3° Facultad de Ingeniería. Universidad de Buenos Aires (FIUBA), Argentina 4° Latin American Brain Health (BrainLat), Universidad Adolfo Ibáñez, Santiago, Chile 5° Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibanez, Santiago, Chile 6° Departamento de Matemática y Ciencias, Universidad de San Andres, Victoria, Buenos Aires, Argentina 7° Departamento de Física, Universidad de Buenos Aires and Instituto de Física de Buenos Aires (IFIBA – CONICET), Buenos Aires, Argentina 8°Instituto de Ingeniería Biomédica, Universidad de Buenos Aires, Buenos Aires, Argentina 9° Unidad de Neurología Cognitiva, Hospital César Milstein, Buenos Aires, Argentina 10°Neuropsychology and Clinical Neuroscience Laboratory, Physiopathology Department, ICBM, Neurosciences Department, Faculty of Medicine, University of Chile, Chile 11° Gerosciences Center for Brain Health and Metabolism, Santiago, Chile 12° Memory and Neuropsychiatric Clinic (CMYN) Neurology Department, Hospital del Salvador & University of Chile, Santiago, Chile 13° Servicio de Neurología, Departamento de Medicina, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile 14° Instituto de Envejecimiento, Department of Psychiatry, School of Medicine, Pontifical Xaverian University, Bogotá, Colombia 15° Department of Mental Health, Hospital Universitario Santa Fe de Bogotá, Bogotá, Colombia 16° Centro de Memoria y Cognición. Intellectus-Hospital Universitario San Ignacio, Bogotá Colombia 17° Pontificia Universidad Javeriana, Departments of Physiology, Psychiatry and Aging Institute Bogotá, Colombia 18°Global Brain Health Institute, University of California-San Francisco, San Francisco, California, 18 and Trinity College Dublin, Ireland 19 National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina 20° Departamento de Lingüística y Literatura, Facultad de Humanidades, Universidad de Santiago de Chile, Chile
Verbal fluency tasks, a cornerstone in Alzheimers disease (AD) assessments, have been historically underexploited. Outcomes are typically restricted to correct responses, which fails to reveal drivers of lexico-semantic deficits and discriminate AD from other disorders. We recruited 32 patients with AD, 32 with behavioral variant frontotemporal dementia, 19 with Parkinsons disease and 27 healthy controls (HCs). Participants performed phonemic and semantic fluency tasks, as well as an executive function test to capture cognitive symptom severity. We counted correct responses and then, from each word, extracted distributional features of six psycholinguistic variables: granularity, frequency, neighborhood, length, familiarity, and imageability. While correct responses revealed significant deficits in each patient group, granularity, frequency and neighborhood did so only in AD. Also, these features, as derived from semantic fluency, predicted executive function outcomes exclusively in AD. A logistic regression classifier integrating all psycholinguistic features robustly discriminated between AD and HCs (AUC=.89), yielding near-chance results for the other two patient groups. Our findings show that objective multivariate psycholinguistic analysis of verbal fluency can reveal fine-grained, disease-specific, and severity-sensitive patterns of semantic memory disintegration in AD, contributing to clinical characterization, differential diagnosis, and cognitive phenotyping.