Chapter 1 looks at how historically the concept of economic agent developed within mainstream economics, and how the concept of artificial agent emerged while cognitive science became the successor of behaviorism. Then, considering that artificial economics tries to build realistic models of artificial agents, it introduces the main models of mental architectures that derive from cognitive science, and some recent advances in neuroscience (specially within neuroeconomics, social neuroscience, and neurosociology) that relate directly to the economic and social behavior of individuals. Finally, it reviews some models and approaches that try to capture the cognitive, neurological, emotional, and social aspects of agents in an integrated way.