Abstract(s) :

(Anglais) Lexical deterioration in Alzheimer’s disease Frédérique Gayraud1, Isabelle Simoes Loureiro², Camille Frouin1, Cynthia Collette², Laurent Lefebvre², Melissa Barkat-Defradas3 1Laboratoire Dynamique du Langage, University of Lyon & CNR, France 2 2Cognitive Psychology and Neuropsychology dept, University of Mons, Belgium 3Institut des Sciences de l’Évolution de Montpellier, France Abstract This research aimed to assess the validity of the retrogenesis hypothesis applied to the lexico-semantic knowledge. According to this hypothesis neurodegenerative mechanisms would reverse the order of acquisition in normal development. We present two studies comparing the development and loss of semantic knowledge. Study 1 compares the development of semantic knowledge about objects in children aged from 5 to 9 years old and its loss in Alzheimer’s disease. Study 2 compares the performances of children and patients with Alzheimer’s disease in a picture naming task. Both studies exhibited mirrored evolution of semantic knowledge extending the retrogenesis theory to lexico-semantic knowledge. Key words: retrogenesis, Alzheimer’s disease, semantic knowledge, lexical access