Medial prefrontal cortex stimulation modulates the processing of conditioned fear

Area of Science:

• Neuroscience
• Psychology
• Cognitive Science

Background:

• Conditioned fear extinction relies on amygdala-mPFC interaction.
• Electrical stimulation of the mPFC in rats reduces amygdala activity and improves fear extinction.
• The efficacy of stimulating homologous human regions for fear extinction is unknown.

Purpose of the Study:

• To investigate the effects of repetitive transcranial magnetic stimulation (rTMS) on the human medial prefrontal cortex (mPFC) in modulating conditioned fear.
• To determine if mPFC rTMS can enhance fear extinction learning and recall.

Main Methods:

• Healthy volunteers underwent a 2-day fear conditioning and extinction paradigm.
• Active or sham rTMS was applied offline to the mPFC after fear acquisition.
• Conditioned responses were measured using fear-potentiated startle (FPS), skin conductance responses (SCR), fNIRS, and self-report scales.

Main Results:

• The active rTMS group exhibited reduced discrimination between conditioned stimuli (CS+/CS-) during extinction learning.
• This reduction was observed in FPS, SCR, and arousal ratings.
• FPS responses to the CS+ showed a linear decrease across both extinction sessions.

Conclusions:

• High-frequency rTMS of the human mPFC can modulate conditioned fear processing.
• This approach represents a novel method for influencing conditioned fear.
• mPFC rTMS may serve as an adjunct to cognitive behavioral therapy for fear extinction.