One of the most impressive changes in economics and decision sciences is the emergence and fast growth of so-called 'behavioral' economics and neuroeconomics. These fields raise several methodological issues, some of them being currently intensively discussed. Amongst those issues, the most prominent is the one of knowing what is the relevance of neuroeconomics for economics and standard decision sciences. The aim of this talk is to discuss this issue, starting from the vigorous criticism of neuroeconomics made by F. Gul and W. Pesendorfer (2005/2008). Mikaël Cozic (Paris-Sorbonne University, Ph.D. 2005) is an assistant professor at the Paris-Est University, a researcher and head of the group 'Decision, rationality and interaction' at the Institut d'Histoire et de Philosophie des Sciences et des Techniques and a member of the Institut d'Universitaire de France. He studied philosophy (Ecole normale Supérieure de Paris, 1997-2002), logic (University Paris-Diderot, M.Sc
. 2002) and cognitive science (Ecole des Hautes Etudes en Sciences Sociales, M.A. 2001) in Paris. Professor Cozic's research focuses primarily on philosophy of economics and formal theories of rationality. His current research concerns the relationship between cognitive science and positive and normative economics, and several issues in Bayesian epistemology including the revision of one's beliefs upon learning the opinion of others.