Tracking post-error adaptation in the motor system by transcranial magnetic stimulation

Area of Science:

• Neuroscience
• Cognitive Psychology
• Motor Control

Background:

• Errors trigger cognitive control for correction and prevention.
• Post-error slowing (PES) may involve motor region and corticospinal tract (CST) excitability changes.
• The temporal dynamics of CST excitability modulation post-error are not well understood.

Purpose of the Study:

• To investigate the time-course of corticospinal tract excitability changes following errors.
• To determine if these changes contribute to post-error adjustments in motor behavior.

Main Methods:

• Single-pulse transcranial magnetic stimulation (TMS) applied to the motor cortex during an Eriksen flanker task.
• Measurement of motor-evoked potentials (MEP) in the first dorsal interosseous (FDI) muscle.
• TMS delivered at 150, 300, and 450 ms after correct and erroneous responses.

Main Results:

• MEP amplitude significantly increased 450 ms after an error.
• This increase was independent of response correction or motor command characteristics.
• Suggests decreased excitability in the active motor cortex, potentially via inverse relationship with contralateral excitability.

Conclusions:

• Post-error motor cortex excitability is modulated to prevent subsequent errors.
• TMS is a valuable tool for exploring the temporal evolution of post-error adjustments in motor systems.
• Findings elucidate the neural mechanisms underlying error processing and behavioral adaptation.