Ensemble viewing reshapes neural representations of same-race and other-race faces

The other-race effect, better recognition of same-race than other-race faces, is established for individual faces. Whether this benefit is reflected in neural representations of face ensembles, as when viewing a crowd, remains unclear. We recorded electroencephalography responses from 22 East Asian adults viewing synthetic East Asian (same-race) and White (other-race) faces in two formats: individually and in six-face ensembles. Multivariate decoding and generative image reconstruction assessed neural discriminability, representational geometry and recoverable visual content. Behavioral testing confirmed a same-race recognition advantage. The corresponding neural decoding advantage depended on viewing format and was not preserved for race-homogeneous ensembles, although their constituents retained it when viewed individually. Early ensemble decoding instead favored other-race faces. Race organized ensemble representations and reconstructed latent vectors matched ensemble summary targets above chance. Independent judgments revealed format-dependent race differences in reconstructed age and arousal relative to model-derived references. These findings constrain accounts of same-race expertise: its benefit for neural discriminability depends on whether faces are represented individually or collectively. Recoverable ensemble-summary information can also coexist with systematic appearance shifts, linking the organization of neural representations to their visual content.