Modulation of the frontal-parietal network by low intensity anti-phase 20 Hz transcranial electrical stimulation boosts performance in the attentional blink task.

Performance in the attentional blink task has been demonstrated to be directly influenced by alpha and beta neural oscillatory activity. In two experiments we stimulated the right parietal cortex and left frontal cortex with transcranial alternating current stimulation. For the first experiment we targeted only the right parietal cortex and found a non-significant increase in performance from 20 Hz stimulation. In the second experiment we applied two stimulators to the right parietal and left frontal cortex and found a significant increase in performance from 20 Hz tACS with a phase difference of 180°. Since low intensity stimulation has been shown to inhibit cortical excitability, and anti-phasic stimulation has been hypothesized to decrease presynaptic activation in one region and drive postsynaptic spikes in the other, we suggest that low intensity anti-phasic 20 Hz stimulation inhibited the parietal cortex, thereby disinhibiting the frontal cortex. This visual attention mechanism supposedly reduces processing of distractor stimuli and enhances processing of target stimuli. This study reveals that the frontal-parietal visual attention network may be modulated with low intensity 20 Hz anti-phase tACS.