Face ensembles reshape the neural other-race effect

Abstract

The other-race effect (ORE), poorer recognition of other-race (OR) than same-race (SR) faces, is established for individual faces, but its neural expression during group viewing remains unclear. Twenty-two East Asian adults viewed East Asian and White faces in different formats: individually and in six-face ensembles during EEG recording. Behavioral testing confirmed an SR advantage. Decoding and generative reconstruction characterized neural discriminability, geometry, dynamics, sensor-level information, and recoverable content. Single SR faces were more discriminable, more dispersed in face space, and reconstructed more accurately. Ensembles preserved racial-composition information but reduced the cumulative SR-OR decoding difference and showed instead an early OR advantage. Reconstructions supported identification of individual faces and ensemble summaries, with an overall SR advantage but no reliable race-by-format interaction. Independent judgments revealed race- and format-dependent shifts in reconstructed age, valence, and arousal. These findings reveal a neural ORE whose expression depends on viewing context and representational measure.