Abstract
We recorded magnetoencephalography (MEG) using a frequency-tagging paradigm with compound face stimuli that allowed for independently frequency-tagging various parts of a face (eyes, mouth) as well as changes in facial identity. Our MRI-guided MEG analyses revealed that different sub-nodes of the human face-processing network were tagged differentially according to their functional specialization. Whereas the occipital face area (OFA) was most responsive to the frequency, at which face parts (e.g., the mouth) changed, the fusiform face area (FFA) was selectively entrained by the rhythmic updating of facial identity. Face patches in the superior temporal sulcus (STS) were mostly entrained by rhythmic changes in the eyes region. Furthermore, top-down attention to the mouth, eyes, or identity of the face selectively modulated the neural processing in the respective area (i.e., OFA, STS, or FFA, respectively), closely resembling behavioral cue validity effects observed in the participants' reaction time and detection rate data. Our results allow new insights in the hierarchical organization of the occipital face processing network and the flow of information among its components. Further, our results illuminate how top-down attention biases the visual processing of different aspects and dimensions within a single face-object, at various stages of the involved visual processing hierarchy.
Meeting abstract presented at VSS 2018