Face processing is integral to human interpersonal relationships, and as such, the brain dedicates substantial resources to this function. Beyond the involvement of several posterior brain cortical regions, there is notable functional connectivity to the frontal lobes. This connectivity is believed to contribute to high-level tasks such as attention, memory, emotion, and error monitoring. Many studies have highlighted significant distant functional covariances, suggesting synchronization among the cortical rhythms of various regions. Among these, the limbic theta rhythm has been frequently posited as a potential synchronizing element. However, the exact causal relationship between this rhythm and its attributed functions remains unclear. In fact, it remains undetermined whether the correlation between EEG brain rhythms and information processing in the same cortical region is causal or merely coincidental.

To investigate this question, our project studied the functional connectivity between the frontal lobe and the posterior brain areas engaged in face visual processing, laying special emphasis on the theta rhythm. We employed Transcranial Magnetic Stimulation (TMS) to experimentally modulate the frontal lobe theta rhythm and observed its subsequent effects on face processing. To ensure the validity of our findings, we controlled for placebo effects using a parallel protocol with sham TMS. Our primary goal was to discern the specific role the frontal lobe theta rhythm plays in the visual processing of faces.