Working memory.

Working memory is an evolving concept that refers to the short-term storage of information that is not accessible in the environment, and the set of processes that keep this information active for later use. From a psychological perspective, working memory has been conceptualized as comprising multiple components such as executive control and active maintenance processes. This chapter will review functional neuroimaging studies (PET and fMRI) that have provided evidence that prefrontal cortex is a critical node in the functional neural network that supports working memory function. Also, recent data will be reviewed regarding the functional organization of prefrontal cortex.