ABSTRACT
This chapter is organized into two sections. The first section consists of a brief examination of the status of a processing speed construct from a psychometric perspective. and the second section is a selective review of potential neurobiological correlates of speed. Although research from psychometric and neurobiological traditions might appear to represent quite different perspectives. we believe that they should be more closely related than is commonly assumed. particularly when. as is the case in this review. they share a common focus on the relation of aging to speed.
