Abstract

In this paper we examine the functional anatomy of volition, as revealed by modern brain imaging techniques, in conjunction with neuropsychological data derived from human and non-human primates using other methodologies. A number of brain regions contribute to the performance of consciously chosen, or ‘willed', actions. Of particular importance is dorsolateral prefrontal cortex , together with those brain regions with which it is connected, via cortico-subcortical and cortico-cortical circuits. That aspect of free will which is concerned with the voluntary selection of one action rather than another critically depends upon the normal functioning of DLPFC and associated brain regions. Disease, or dysfunction, of these circuits may be associated with a variety of disorders of volition: Parkinson's disease, ‘utilization’ behaviour, ‘alien’ and ‘phantom’ limbs, and delusions of ‘alien control’ . Brain imaging has allowed us to gain some access to the pathophysiology of these conditions in living patients. At a philosophical level, the distinction between ‘intentions to act', and ‘intentions in action’ may prove particularly helpful when addressing these complex disturbances of human cognition and conscious experience. The exercise and experience of free will depends upon neural mechanisms located in prefrontal cortex and associated brain systems