Informative cues affect proactive modulation of corticospinal excitability during a selective vs. global stop signal task

The ability to inhibit and reprogram movement in response to changing goals is fundamental to successful engagement with the world (Bestmann & Duque, 2016). The current study utilised single pulse transcranial magnetic stimulation (TMS) to explore modulation of corticospinal excitability (CSE) in 23 (12 female) young adults during movement preparation in a task that required unimanual (selective) or bimanual (global) stopping of a bimanual button press. On some trials a cue informed participants of the stop type that might be required. Overall, CSE in the non-stopping hand was greater than in the hand that was cued to stop, which supports a facilitation model of CSE modulation. Behaviourally, there was a significantly reduced selective stopping cost (SSC) and improved stopping performance during cued trials. However, no significant differences in CSE modulation or stopping performance were observed between selective and global stopping. These findings support a flexible and generic mechanism for inhibition, rather than independent mechanisms for global and selective stopping. This research contributes to a body of literature aiming to elucidate the neural underpinnings of inhibition, which is essential for understanding how it is impaired in healthy ageing or conditions like Attention Deficit Hyperactive Disorder (ADHD), Schizophrenia, or Tourette's Syndrome.