The visual processing of faces plays a major role in the inter-personal relationships in humans and, consequently, the brain dedicates a lot of resources to this task. Besides the contribution of multiple posterior brain cortical areas, there is functional connectivity to the frontal lobes, which is likely to be related to emotions and memory. Several studies have demonstrated significant functional covariances at a distance, which seem to implicate synchronization between the cortical rhythms of the different areas. The limbic theta rhythm has gained particular prominence as a possible synchronizing mechanism between distant areas, despite the fact that no strong causal between this rhythm and the functions that are attributed to it have been demonstrated. Specifically, it has not been possible to demonstrate whether the association between EEG brain rhythms and the information processing taking place in the same cortical area is a causal one and not an epiphenomena.

To give an experimental response to the last point, it was planned to study the functional connectivity between the frontal lobe and the posterior brain areas involved in the visual processing of faces, with a special emphasis in the theta rhythm. Experimental modulation of the frontal lobe theta rhythm was performed using TMS, and the resulting effects in the processing of faces were determined. The effect of placebo was controlled by using a similar protocol but with sham TMS. The final outcome of the study was a detailed characterization of the role played by the frontal lobe theta rhythm in several aspects of the visual processing of faces.