Partial Face Visibility and Facial Cognition: An Electroencephalography and Eye-Tracking Investigation

Face masks became a part of everyday life in the SARS-CoV-2 pandemic. Previous studies showed that the face cognition mechanism involves holistic face processing, and the absence of face features could lower cognition ability. This is opposed to the experience during the pandemic, when people were able to correctly recognize faces, although the mask covered a part of the face. This paper shows a strong correlation in face cognition based on the EEG and eye-tracking data between the full and partial faces. We observed two event-related potentials, P3a in the frontal lobe and P3b in the parietal lobe, as subcomponents of P300. Both P3a and P3b were lowered when the eyes were invisible, and P3a evoked by the nose covered was larger than the full face. The eye-tracking data showed that 16 out of 18 participants focused on the eyes associated with the EEG results. Our results demonstrate that the eyes are the most crucial feature of facial cognition. Moreover, the face with the nose covered might enhance cognition ability due to the visual working memory capacity. Our experiment shows the possibility of people recognizing faces using both holistic face processing and structural face processing. Furthermore, people can recognize the masked face as well as the full face in similar cognition patterns due to the high correlation in the cognition mechanism.