Gender dimorphic M1 excitability during emotional processing: a transcranial magnetic stimulation study

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Psychology

Background:

• Emotions are thought to prepare the body for action.
• The impact of gender on primary motor cortex (M1) excitability during emotional processing remains under-investigated.

Purpose of the Study:

• To investigate gender differences in primary motor cortex (M1) excitability.
• To explore the functional lateralization of motor excitability in response to emotional stimuli.

Main Methods:

• Utilized single-pulse transcranial magnetic stimulation (TMS) to assess corticospinal excitability.
• Measured motor-evoked potentials (MEPs) ratio in response to emotional picture stimuli (negative, neutral, positive).
• Stimulated the right or left primary motor cortex (M1) at 150 ms and 300 ms post-stimulus onset in male and female participants.

Main Results:

• Males exhibited higher MEP ratios in the right M1 at 150 ms after negative stimuli.
• Males showed greater MEP ratios in the right M1 at 300 ms after positive stimuli.
• Males demonstrated lateralized motor excitability, with larger MEP ratios in the right M1 compared to the left M1 at 300 ms following positive stimuli.

Conclusions:

• Provides neurophysiological evidence for gender differences in motor excitability.
• Supports functional lateralization of motor excitability in males in response to emotional stimuli.