High-definition transcranial direct current stimulation dissociates fronto-visual theta lateralization during visual...

Area of Science:

• Neuroscience
• Cognitive Science
• Brain Stimulation

Background:

• Visual attention relies on oscillatory activity in visual and prefrontal cortices.
• Prefrontal cortex laterality in attention processing remains poorly understood.
• Oscillatory dynamics are crucial for organizing attended information.

Purpose of the Study:

• To investigate prefrontal cortex laterality effects in visual selective attention.
• To examine how high-definition transcranial direct current stimulation (HD-tDCS) modulates attention-related oscillatory networks.
• To determine if left vs. right dorsolateral prefrontal cortex (DLPFC) stimulation differentially impacts performance and neural dynamics.

Main Methods:

• Randomized crossover design with 27 healthy adults.
• Three HD-tDCS sessions: sham, left DLPFC, and right DLPFC.
• Magnetoencephalography (MEG) and beamforming used to analyze oscillatory dynamics and functional connectivity.

Main Results:

• Left DLPFC stimulation modulated right fronto-visual theta oscillations, unlike right DLPFC stimulation.
• Increased right fronto-visual network connectivity was observed after left DLPFC stimulation.
• Faster performance in detecting targets among distractors was linked to enhanced right fronto-visual connectivity.

Conclusions:

• Findings demonstrate clear laterality effects in theta oscillatory activity along prefrontal-visual pathways.
• HD-tDCS can dynamically modulate specific fronto-visual network connectivity.
• This provides network-specific insights into the oscillatory mechanisms of visual selective attention.