Anodal Transcranial Direct Current Stimulation Increases Bilateral Directed Brain Connectivity during Motor-Imagery...

Area of Science:

• Neuroscience
• Brain-Computer Interfaces
• Neuroimaging

Background:

• Transcranial direct current stimulation (tDCS) influences motor and cognitive performance.
• Previous research indicates tDCS alters brain connectivity at rest.
• The interaction between tDCS and task-specific brain activity on connectivity remains unclear.

Purpose of the Study:

• To investigate the aftereffects of anodal high-definition tDCS on motor network connectivity during a sensorimotor rhythm brain-computer interface (SMR-BCI) task.
• To determine how tDCS-induced connectivity changes relate to task performance.

Main Methods:

• Anodal high-definition tDCS was applied over the left sensorimotor cortex.
• Participants performed a 1D EEG-based SMR-BCI task involving left and right hand imagination.
• Directed connectivity analysis was used to assess changes in motor network communication.

Main Results:

• Anodal tDCS altered bilateral frontal and parietal connectivity in a task-specific manner.
• Right-hand imagination showed increased outflow from the left premotor cortex and increased inflow to the sensorimotor cortex.
• Left-hand imagination revealed increased outflow from the sensorimotor cortex.
• Connectivity changes correlated with behavioral measures like correct trials and time-to-hit.

Conclusions:

• tDCS interacts with endogenous task-specific activity to modulate directed connectivity during SMR-BCI.
• Understanding this interaction is crucial for predicting and maximizing tDCS efficacy.
• Further research is needed to comprehensively examine the interplay between stimulation and endogenous brain dynamics.