This volume is devoted to mathematical models of the cortex. Computati onal models of individual neurons and ensembles of neurons are increas ingly used in research on cortical organization and function. This is, in part, because of the now ubiquitous presence of powerful and affor dable computers. The volume begins with a short history of models of c ortical neurons and circuitry that introduces the principal modeling s tyles. An attempt has been made throughout the volume to make it acces sible to readers with minimal mathematical backgrounds.