Mechanisms of control

This chapter is mainly concerned with functional imaging studies that illustrate different approaches to the study of control mechanisms. The prefrontal cortex does not act by itself. The executive properties of prefrontal cortex emerge through interactions with other brain areas. However, in this chapter we are largely concerned with attempts to assign specific control functions to different regions of prefrontal cortex. First, it discusses why it has proved so difficult to anatomize prefrontal function. The main problem with prefrontal cortex is that no obvious mapping has been found between subregions and function. Then it focuses on the evidence for functional specialization in prefrontal cortex. This chapter further discusses imaging frontal tasks. This includes the Wisconsin Card Sorting test (WCST), the Tower of London (TOL) task, and the Stroop Task. If one is to understand the role of prefrontal cortex in higher cognitive functions one need to take into account a much wider range of evidence. One needs to be much more precise in characterization of cognitive functions and much more accurate in the localization of brain activity.