Neural Architecture of Familiar Person Perception: Contributions of Unimodal and Multimodal Brain Regions.

Faces and voices provide essential information for recognizing familiar people. The brain regions involved in processing person familiarity through these modalities have typically been studied independently, leaving unclear whether and where the auditory and visual networks overlap. In this study, we developed a novel frequency-tagging-based fMRI paradigm to examine the neural basis of familiarity processing from a multimodal perspective. Our findings indicate that the perception of person familiarity through faces and voices predominantly activates sensory-specific regions-the posterior superior temporal cortex (pSTC) for faces and the anterior superior temporal cortex (aSTC) for voices. Discrete regions in the temporal (posterior superior temporal sulcus, pSTS) and frontal (inferior frontal cortex, IFC) areas showed overlapping multisensory activity. pSTS sits as a spatial boundary between unimodal regions, whereas IFC shows connectivity-driven convergence without boundary constraints. These findings indicate shared neural processes for familiarity processing from faces and voices. All together, these results highlight the presence of distributed unisensory and multisensory networks engaging in recognizing familiar people.