Rigid facial motion at study facilitates the holistic processing of own-race faces during the structural encoding stage

Abstract

Holistic processing is a fundamental element of face-recognition studies. Some behavioral studies have investigated the impact of rigid facial motion on holistic face processing, yet it is still unclear how rigid motion affects the time course of holistic face processing for different face races. The current study investigated this issue, using the composite face effect (CFE) as a direct measure of holistic processing. Participants were asked to match the identity of the top half of a static composite face with the study face during the test stage, where the study face was either static or rigidly-moving. ERP results showed that rigidly-moving study faces elicited a larger CFE relative to static study faces in the N170 component when recognizing own-race faces. The amplitude of P1, N170 and P2 components indicated that rigid motion facilitated holistic face processing, with differences observed between the hemispheres over time. Specifically, the CFE was only observed after exposure to rigidly-moving faces in the P1 and P2 components of the right hemisphere. Additionally, a greater CFE was observed following exposure to rigidly-moving faces compared to static faces, particularly in the N170 component of the left hemisphere. This study suggests that holistic processing is a fundamental aspect of face perception that applies to both static and moving faces, not just static ones. Furthermore, rigid facial motion improves holistic processing of own-race faces during the structural encoding stage. These findings provide evidence of distinct neural mechanisms underlying the holistic processing of static and moving faces.