Increased corticospinal excitability induced by unpleasant visual stimuli

Area of Science:

• Neuroscience
• Psychology
• Cognitive Science

Background:

• Emotional stimuli are considered motivators for action.
• Understanding the neural basis of emotion-action links is crucial.

Purpose of the Study:

• To investigate if negative emotions selectively enhance motor cortex excitability.
• To examine the relationship between emotional valence and motor system activation.

Main Methods:

• Utilized focal transcranial magnetic stimulation (TMS) on the right motor cortex.
• Measured corticomotor excitability via motor evoked potentials (MEPs).
• Participants viewed pleasant, neutral, and unpleasant images from the International Affective Picture System (IAPS).

Main Results:

• Corticomotor excitability was significantly higher when viewing negative pictures compared to neutral or positive images.
• No significant difference in excitability was observed between pleasant and neutral pictures.
• Motor evoked potentials (MEPs) were larger during negative picture viewing.

Conclusions:

• Negative emotions appear to have direct connections to motor response systems.
• Findings support models where negative emotions have a preferential link to action preparation.
• The motor system shows heightened responsiveness to unpleasant emotional stimuli.