Enhancing response inhibition through a novel tES-fNIRS framework.

Area of Science:

• Neuroscience
• Cognitive Science
• Neuromodulation

Background:

• Transcranial electrical stimulation (tES) shows promise for modulating response inhibition.
• Limited research compares different tES paradigms and their neurophysiological mechanisms.

Purpose of the Study:

• To investigate the effects of transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) on response inhibition.
• To examine prefrontal cortex hemodynamic changes using fNIRS during tES.
• To compare tDCS and tACS effects on the right inferior frontal gyrus (IFG).

Main Methods:

• 229 healthy male adults were randomly assigned to tACS, tDCS, or sham groups.
• Participants underwent response inhibition tasks (Stroop effect) during tES.
• Functional near-infrared spectroscopy (fNIRS) monitored hemodynamic responses in the prefrontal cortex (PFC).

Main Results:

• Both tDCS and tACS significantly reduced the Stroop effect, improving response inhibition.
• A significant interaction was found for the Stroop effect (F(2,102)=4.144, P=0.019).
• fNIRS indicated tDCS uniquely decreased oxy-hemoglobin in the PFC, suggesting enhanced neural efficiency.

Conclusions:

• Both tDCS and tACS enhance response inhibition.
• tDCS may improve neural efficiency by reducing cognitive load during right IFG stimulation.
• Findings provide insights into tES mechanisms for potential neurological disorder treatments.