Human motor fatigability as evoked by repetitive movements results from a gradual breakdown of surround inhibition

Marc Baechinger, Rea Lehner, Felix Thomas, Samira Hanimann, Joshua Balsters, Nicole Wenderoth

Research output: Contribution to journalArticlepeer-review


Motor fatigability emerges when demanding task are executed over an extended period of time. Here, we used repetitive low-force movements that cause a gradual reduction in movement speed (or “motor slowing”) to study the central component of fatigability in healthy adults. We show that motor slowing is associated with a gradual increase of net excitability in the motor network and, specifically, in primary motor cortex (M1), which results from overall disinhibition. Importantly, we link performance decrements to a breakdown of surround inhibition in M1, which is associated with high coactivation of antagonistic muscle groups. This is consistent with the model that a loss of inhibitory control might broaden the tuning of population vectors such that movement patterns become more variable, ill-timed and effortful. We propose that the release of inhibition in M1 is an important mechanism underpinning motor fatigability and, potentially, also pathological fatigue as frequently observed in patients with brain disorders.
Original languageEnglish
Article numbere46750
Pages (from-to)1-30
Number of pages30
Publication statusPublished - 16 Sept 2019


  • Fatigue
  • motor slowing
  • repetitive movements
  • functional magnetic resonance imaging
  • electrophysiology
  • Transcranial magnetic stimulation

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