Exploring the importance of shape on dynamic recognition of self-face or friend-face.

Our own face is well-known to us, but it is unclear whether we perceive it in the same way as other familiar faces. Unlike others’ faces, self-faces provide limited opportunities to observe facial motion. This study investigated the importance of shape when recognizing self or friend from dynamic face clips. Dynamic sequences were created using Deepfake, manipulating face shape and motion independently. In both experiments, participants observed a visually presented face and identified whether the face motion was self or friend. In Experiment 1, face shape was manipulated to match or mismatch the dynamic parameters of the observed person. In Experiment 2, the contribution of self- and friend- shape was manipulated in a series of stages to match or mismatch the dynamic parameters. The results showed the identification of the friends’ face motion was independent of the observed face shape. However, self-face motion could not be clearly identified until the face shape was judged to be self-face. These results support the prediction that self-face motion identification is more dependent on face shape, compared to another familiar friend face. We propose that self-faces may have specific perceptual characteristics that are distinct from the recognition of other familiar faces.