Functional specificity of human premotor-motor cortical interactions during action selection

Eur J Neurosci. 2007 Oct;26(7):2085-95. doi: 10.1111/j.1460-9568.2007.05795.x. Epub 2007 Sep 14.


Functional connections between dorsal premotor cortex (PMd) and primary motor cortex (M1) have been revealed by paired-pulse transcranial magnetic stimulation (TMS). We tested if such connections would be modulated during a cognitive process (response selection) known to rely on those circuits. PMd-M1 TMS applied 75 ms after a cue to select a manual response facilitated motor-evoked potentials (MEPs). MEPs were facilitated at 50 ms in a control task of response execution, suggesting that PMd-M1 interactions at 75 ms are functionally specific to the process of response selection. At 100 ms, PMd-M1 TMS delayed choice reaction time (RT). Importantly, the MEP (at 75 ms) and the RT (at 100 ms) effects were correlated in a way that was hand-specific. When the response was made with the M1-contralateral hand, MEPs correlated with slower RTs. When the response was made with the M1-ipsilateral hand, MEPs correlated with faster RTs. Paired-pulse TMS confined to M1 did not produce these effects, confirming the causal influence of PMd inputs. This study shows that a response selection signal evolves in PMd early during the reaction period (75-100 ms), impacts on M1 and affects behaviour. Such interactions are temporally, anatomically and functionally specific, and have a causal role in choosing which movement to make.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping
  • Choice Behavior / physiology*
  • Electromyography / methods
  • Evoked Potentials, Motor / physiology*
  • Female
  • Functional Laterality
  • Humans
  • Male
  • Motor Cortex / physiology*
  • Neural Pathways / physiology
  • Photic Stimulation / methods
  • Reaction Time / physiology*
  • Time Factors
  • Transcranial Magnetic Stimulation*