Impact of Electric Field Magnitude in the Left Dorsolateral Prefrontal Cortex on Changes in Intrinsic Functional...

Area of Science:

• Neuroscience
• Neuroimaging
• Brain Stimulation

Background:

• Transcranial direct current stimulation (tDCS) shows variable responses, partly due to unclear effects on resting-state brain activity and functional connectivity.
• Understanding how tDCS influences resting-state functional connectivity (rsFC) is crucial for optimizing therapeutic applications.

Purpose of the Study:

• To investigate the impact of electric field (E-field) magnitude from tDCS on resting-state brain activity and L-DLPFC rsFC.
• To explore the relationship between individual E-field modeling and observed changes in brain activity and connectivity.

Main Methods:

• Twenty-one healthy participants received anodal or sham tDCS targeting the L-DLPFC.
• Brain imaging (fALFF for activity, rsFC) was performed before and after stimulation.
• Individual E-fields were modeled and correlated with fALFF and rsFC changes.

Main Results:

• Anodal tDCS increased fALFF in the left rostral middle frontal area and decreased it in the midline frontal area.
• Sham stimulation led to significant decreases in overall rsFC, while anodal tDCS showed modest, non-significant changes.
• Correlations were found between the modeled E-field and rsFC changes in the L-DLPFC, left inferior parietal, and right lateral visual areas.

Conclusions:

• Single-session tDCS can modulate resting brain activity and potentially help maintain overall rsFC.
• The E-field magnitude in the targeted L-DLPFC is associated with rsFC alterations in both nearby and distant brain regions.