Neurodynamic correlates for the cross-frequency coupled transcranial alternating current stimulation during working...

Area of Science:

• Neuroscience
• Cognitive Science
• Neuromodulation

Background:

• Transcranial current stimulation (tACS) is a non-invasive neuromodulation technique.
• tACS modulates brain oscillations to enhance cognitive functions.
• Cross-frequency coupling (CFC) involves interactions between different brain oscillation frequencies.

Purpose of the Study:

• To investigate if cross-frequency coupled transcranial alternating current stimulation (CFC-tACS) improves working memory performance.
• To identify neurophysiological correlates of tACS-mediated working memory enhancement.

Main Methods:

• Participants performed a modified Sternberg task.
• Theta-phase/high-gamma-amplitude CFC-tACS was applied over frontal electrodes (F3 and surrounding) for 20 minutes.
• EEG data (alpha/theta power, cross-frequency coupling, functional connectivity, nodal efficiency) were analyzed during the working memory task's retention period.

Main Results:

• The CFC-tACS group showed significantly reduced reaction times compared to the sham group.
• tACS modulated fronto-occipital neurodynamics, specifically dissociations between alpha suppression and delta/theta enhancement.
• Functional connectivity and top-down control across fronto-occipital regions were modulated by tACS.

Conclusions:

• CFC-tACS is a feasible method for enhancing working memory performance.
• The study demonstrates tACS's ability to modulate brain activity and improve cognitive function.
• Findings suggest CFC-tACS influences neural network dynamics underlying working memory.