Cognitive control activity is enhanced by single pulse transcranial magnetic stimulation over prefrontal and premotor areas

Cognitive control, which includes a set of processes to implement goal directed actions and flexible behaviour, is related to a set of brain areas comprising prefrontal, premotor, and parietal cortex. However, the functional relationships between these areas and the neural correlates underlying the specific cognitive processes linked to cognitive control (e.g., inhibition and working memory update) are still unclear. In the present study, participants performed a spatial cognitive control task (i.e., a Simon task) during a transcranial magnetic stimulation electroencephalogram (TMS-EEG) co-registration. In different blocks of the task, single pulse TMS was applied over the left prefrontal, premotor, and parietal regions (a sham TMS condition was also included) at 180ms after the stimulus onset. Behavioural differences between the four TMS conditions were not observed. Accordingly, activity to inhibit the response toward the attended location was not modulated by TMS, as indexed by the contralateral central negativity (N2cc), even if TMS over parietal regions accelerated the visuospatial processing, as evidenced by faster contralateral posterior negativity (N2pc). Importantly, we observed larger P300 amplitude when delivering TMS over prefrontal and premotor cortex compared to the sham condition. These results suggest that TMS applied over the left prefrontal and premotor regions could enhances working memory processes linked to switch-and-update of the stimulus-response binding and align with the existence of prefrontal-premotor connections.