Negative emotion can enhance human motor cortical plasticity

Area of Science:

• Neuroscience
• Cognitive Psychology
• Motor Control

Background:

• Emotion primes action, but its impact on motor system plasticity is poorly understood.
• The interplay between emotion and motor plasticity, despite links to memory, remains unclear.

Purpose of the Study:

• To investigate if emotion modulates the plasticity of the human primary motor cortex.
• To determine the differential effects of negative, positive, and neutral emotions on motor cortex plasticity.

Main Methods:

• Utilized the International Affective Picture System (IAPS) and transcranial magnetic stimulation (TMS).
• Applied intermittent theta-burst stimulation (TBS) to the primary motor cortex to induce long-term potentiation-like changes.
• Assessed changes in primary motor cortex plasticity under different emotional conditions.

Main Results:

• Primary motor cortex plasticity was significantly enhanced and sustained only when TBS was paired with negative emotional stimuli.
• Negative emotion enhanced both excitatory and inhibitory systems within the primary motor cortex.
• Improved motor behavior was observed during a choice reaction-time task following negative emotion induction.

Conclusions:

• Negative emotion enhances primary motor cortex plasticity, potentially via modulation of the intracortical GABAergic system and NMDA receptor-dependent pathways.
• Findings suggest a physiological basis for motor symptoms in psychogenic movement disorders linked to emotional events.
• This research highlights the crucial role of negative affect in shaping motor system adaptability.