Modulating emotion processing using transcranial alternating current stimulation (tACS) - A sham-controlled study in...

Area of Science:

• Neuroscience
• Cognitive Science
• Neuromodulation

Background:

• Transcranial alternating current stimulation (tACS) is an emerging non-invasive neuromodulation technique.
• tACS applications include mood regulation, cognitive modulation, and brain trauma recovery.
• The precise mechanisms and effects of tACS on emotion processing remain unclear.

Purpose of the Study:

• To investigate the neuromodulatory mechanisms and effects of tACS on emotion processing.
• To explore the impact of prefrontal lobe tACS on emotional state and cognitive processing.
• To examine tACS effects on brain rhythm and attention modulation.

Main Methods:

• A single-blind experiment with 44 healthy subjects in a 1:1 randomized design (tACS vs. sham stimulation).
• tACS applied to the prefrontal lobe at 10 Hz.
• Two experimental paradigms: resting state (eyes open/closed) and emotional face oddball task.
• Analysis of power spectrum and event-related potentials (ERPs).

Main Results:

• The tACS group exhibited significantly enhanced alpha rhythm activity, particularly in the parieto-occipital lobe.
• Reduced misclassification of neutral emotions as negative emotions was observed post-tACS.
• Significantly higher P2 and P3 amplitudes in ERPs during the emotional face task in the tACS group.

Conclusions:

• tACS can modulate and enhance alpha rhythm activity by synchronizing alpha oscillations in the frontoparietal attention network.
• tACS improves cognitive bias towards negative emotions.
• Enhanced emotion processing, at both early and late attentional levels, is achieved through tACS.