Agent-dependent modulation of corticospinal excitability during painful transcutaneous electrical stimulation

Neuroimage. 2020 Aug 15:217:116897. doi: 10.1016/j.neuroimage.2020.116897. Epub 2020 May 11.

Abstract

Pain has an inhibitory effect on the corticospinal excitability that has been interpreted as an evolutionary mechanism, directed to down-regulate cortical activity in order to facilitate rapid protective spinal reflexes. Here, we focused on the link between defensive mechanisms and motor system and we asked whether voluntary actions can modulate the corticospinal excitability during painful stimulations. To this aim, we manipulated the volition-related aspects of our paradigm by comparing conditions in which either the participant (self-generated action) or the experimenter (other-generated action) pressed the button to deliver painful high-intensity transcutaneous electric shocks to the right digit V. MEPs to TMS were recorded from the FDI and APB muscles of the stimulated hand. A compelling agent-dependent modulation of the corticospinal excitability was found, showing, in self-generated compared to other-generated actions, a significantly lower inhibitory effect, as measured by greater MEP amplitude. This finding suggests a top-down modulation of volitional actions on defensive mechanisms, promoting the view that predictive information from the motor system attenuates the responses to the foreseeable adverse events generated by one's own actions as compared to unpredictable events generated by someone else's actions.

Keywords: Corticospinal excitability; Defensive motor responses; Motor control; Pain perception; Sense of agency; Sensorimotor predictions; Sensory attenuation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Efferent Pathways / physiopathology
  • Electromyography
  • Electroshock
  • Evoked Potentials, Motor
  • Female
  • Fingers / physiology
  • Humans
  • Male
  • Muscle, Skeletal / innervation
  • Pain / physiopathology*
  • Pyramidal Tracts / physiopathology*
  • Reflex
  • Self Report
  • Transcranial Magnetic Stimulation
  • Transcutaneous Electric Nerve Stimulation*
  • Volition
  • Young Adult