The Département d'Etudes Cognitives (DEC) is an interdisciplinary department of Ecole normale supérieure (ENS), at the crossroads of the humanities and social sciences, life sciences, and engineering. Training and research at DEC focus on higher mental functions such as perception, attention, decision making, reasoning, language, emotions, action, and social skills.

DEC hosts the Institut d'Etude de la Cognition (IEC), an excellence laboratory (Labex) created in 2011 and financed by the French ministry of higher education and research.