title: Short-latency influence of medial frontal cortex on primary motor cortex during action selection under conflict.
abstract: Medial frontal cortex (MFC) is crucial when actions have to be inhibited, reprogrammed, or selected under conflict, but the precise mechanism by which it operates is unclear. Importantly, how and when the MFC influences the primary motor cortex (M1) during action selection is unknown. Using paired-pulse transcranial magnetic stimulation, we investigated functional connectivity between the presupplementary motor area (pre-SMA) part of MFC and M1. We found that functional connectivity increased in a manner dependent on cognitive context: pre-SMA facilitated the motor evoked-potential elicited by M1 stimulation only during action reprogramming, but not when otherwise identical actions were made in the absence of conflict. The effect was anatomically specific to pre-SMA; it was not seen when adjacent brain regions were stimulated. We discuss implications for the anatomical pathways mediating the observed effects.
authors.affiliation: Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom. rogier.mars@psy.ox.ac.uk
authors.forename: Rogier B
authors.initials: RB
authors.lastname: Mars
authors.forename: Miriam C
authors.initials: MC
authors.lastname: Klein
authors.forename: Franz-Xaver
authors.initials: FX
authors.lastname: Neubert
authors.forename: Etienne
authors.initials: E
authors.lastname: Olivier
authors.forename: Ethan R
authors.initials: ER
authors.lastname: Buch
authors.forename: Erie D
authors.initials: ED
authors.lastname: Boorman
authors.forename: Matthew F S
authors.initials: MF
authors.lastname: Rushworth
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D003118:Color Perception / Q000502:physiology; D003220:Conflict, Psychological; D004558:Electric Stimulation; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology*; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult