Although face processing has been studied extensively, the dynamics of how face-selective cortical areas are engaged remains unclear. Here we uncovered the timing of activation in core face-selective regions using functional Magnetic Resonance Imaging and Magnetoencephalography in humans. Processing of normal faces started in the posterior occipital areas and then proceeded to anterior regions. This bottom-up processing sequence was also observed even when internal facial features were misarranged. However, processing of two-tone Mooney faces lacking explicit prototypical facial features engaged top-down projection from the right posterior fusiform face area to right occipital face area. Further, face-specific responses elicited by contextual cues alone emerged simultaneously in the right ventral face-selective regions, suggesting parallel contextual facilitation. Together, our findings chronicle the precise timing of bottom-up, top-down, as well as context-facilitated processing sequences in the occipital-temporal face network, highlighting the importance of the top-down operations especially when faced with incomplete or ambiguous input.
The source data files have been provided for Figures 2, 3, 4, 5 and S2. MEG source activation data (processed based on original fMRI and MEG datasets ) have been deposited in Open Science Framework and can be accessed at https://osf.io/vhefz/.
MEG face experimentsOpen Science Framework, vhefz.
- Sheng He
- Fan Wang
- Peng Zhang
- Sheng He
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Human subjects: All subjects (age range 19-31) provided written informed consent and consent to publish before the experiments, and experimental protocols were approved by the Institutional Review Board of the Institute of Biophysics, Chinese Academy of Sciences (# 2017-IRB-004). The image used in Figure 3 is a photograph of one of the authors and The Consent to Publish Form was obtained.
- Ming Meng, South China Normal University, China
© 2020, Fan et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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