title: Volition and conflict in human medial frontal cortex.
abstract: Controversy surrounds the role of human medial frontal cortex in controlling actions. Although damage to this area leads to severe difficulties in spontaneously initiating actions, the precise mechanisms underlying such "volitional" deficits remain to be established. Previous studies have implicated the medial frontal cortex in conflict monitoring and the control of voluntary action, suggesting that these key processes are functionally related or share neural substrates. Here, we combine a novel behavioral paradigm with functional imaging of the oculomotor system to reveal, for the first time, a functional subdivision of the pre-supplementary motor area (pre-SMA) into anatomically distinct areas that respond exclusively to either volition or conflict. We also demonstrate that activity in the supplementary eye field (SEF) distinguishes between success and failure in changing voluntary action plans during conflict, suggesting a role for the SEF in implementing the resolution of conflicting actions. We propose a functional architecture of human medial frontal cortex that incorporates the generation of action plans and the resolution of conflict.
authors.affiliation: Department of Visual Neuroscience, Imperial College London, St Dunstan's Road, London W6 8RP, United Kingdom.
authors.forename: Parashkev
authors.initials: P
authors.lastname: Nachev
authors.forename: Geraint
authors.initials: G
authors.lastname: Rees
authors.forename: Andrew
authors.initials: A
authors.lastname: Parton
authors.forename: Christopher
authors.initials: C
authors.lastname: Kennard
authors.forename: Masud
authors.initials: M
authors.lastname: Husain
mesh_terms: D000328:Adult; D002755:Choice Behavior / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003220:Conflict, Psychological; D003657:Decision Making / Q000502:physiology; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D012438:Saccades / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014836:Volition / Q000502:physiology*