Mainen (born 20 February 1969, Bethesda, Maryland, United States of America) is an American neuroscientist whose research focuses on the brain mechanisms of decision-making.Zachary Mainen moved to Lisbon, Portugal in 2007 and has been the Director of the Champalimaud Neuroscience Programme (CNP) at the Champalimaud Centre for the Unknown in Lisbon, Portugal, since 2009.
He is also leader of the Systems Neuroscience Lab and is the founding director of the International Doctoral Neuroscience Programme (INDP).