From global to local: ERP repetition effects reveal a configural-to-featural pattern in face processing.

Understanding the temporal dynamics of face processing is crucial for clarifying how the brain distinguishes individuals within a visually homogeneous category. Previous findings on the processing order of featural information (individual facial features such as eyes and mouth) and configural information (spatial relations among facial features) have been inconsistent. This inconsistency may partly stem from incomplete separation of these information types and uncontrolled low-level visual differences across conditions. In the present study, we addressed these issues by combining a one-back face task with an EEG-based repetition suppression paradigm. The stimuli were carefully constructed such that visual variability was equated between featural and configural manipulations. Twenty-eight participants viewed sequences of faces in which either features or configurations were repeated, or both were altered, and responded whenever the current face matched the preceding one. Event-related potential (ERP) repetition effects associated with featural and configural information were calculated by comparing each repeated condition with the altered condition. ERP waveform analyses at predefined regions of interest and data-driven whole-scalp comparisons revealed that configural repetition effects were consistently observed at earlier time windows, whereas featural effects were more variable and primarily observed at later time windows. These findings clarify the temporal dynamics of face processing, indicate a relative precedence of configural over featural information, and provide empirical constraints for models of hierarchical face representation.