Neural and behavioral correlates of intentional actions.

An essential characteristic of human behavior is the ability to act out of intrinsic motivation to achieve desired goals. These kinds of actions have been classed as intentional or voluntary. They contrast with actions that are performed in response to external stimuli. Recent research has begun to explore the functional underpinnings of internally guided actions and how they differ from externally guided actions. From these studies, one can conclude that the two action modes differ with respect to their neural and behavioral correlates. Most importantly, functional neuroimaging and also lesion studies point to a crucial role of the frontomedian cortex in intentional actions. The present paper reviews the neuroanatomical, behavioral, electroencephalographical and functional neuroimaging findings related to intentional actions.The reviewed data suggest two dimensions for the control of action: First, a medial-lateral dimension with regard to intentional vs. stimulus-based action control. Second, an anterior-posterior dimension related to more abstract vs. specific decisions of action parameters.