The emergence of language, social intelligence, and tool development are what made homo sapiens sapiens differentiate itself from all other biological species in the world. The use of language and the management of social and instrumental skills imply an awareness of intention and the consideration that one faces another individual with an attitude analogical to that of one's own. The metaphor of 'mirror' aptly comes to mind.Recent investigations have shown that the human ability to 'mirror' other's actions originates in the brain at a much deeper level than phenomenal awareness. A new class of neurons has been discovered in the premotor area of the monkey brain: 'mirror neurons'. Quite remarkably, they are tuned to fire to the enaction as well as observation of specific classes of behavior: fine manual actions and actions performed by mouth. They become activated independent of the agent, be it the self or a third person whose action is observed. The activation in mirror neurons is automatic and binds the observation and enaction of some behavior by the self or by the observed other. The peculiar first-to-third-person 'intersubjectivity' of the performance of mirror neurons and their surprising complementarity to the functioning of strategic communicative face-to-face (first-to-second person) interaction may shed new light on the functional architecture of conscious vs. unconscious mental processes and the relationship between behavioral and communicative action in monkeys, primates, and humans. The present volume discusses the nature of mirror neurons as presented by the research team of Prof. Giacomo Rizzolatti (University of Parma), who originally discovered them, and the implications to our understanding of the evolution of brain, mind and communicative interaction in non-human primates and man.(Series B)