High-level attentional selection results in repulsive biases in face space.

Object-based attention enhances processing of attended relative to unattended objects across categories, but how selection functions within a category, where visual features are similar and confusable, remains less well understood. For simple, low-level features, research has shown that attention can bias similar representations away from each other to exaggerate perceptual differences. We investigated how attention operates when selecting visually similar objects from the same category-a face among other similar faces. Participants performed visual search to identify a unique target face among similar or distinct distractors that differed only in their emotional expression. Following search, we probed the perceptual representation of the target face using a two-alternative forced choice task where participants indicated the target's emotional expression. Participants consistently reported the target's emotion as more distinct from distractors when target-distractor search similarity was high. These findings demonstrate that attention can bias representations of complex, high-level stimuli to increase the perceptual distinctiveness between targets and similar distractors in support of selection, mirroring attentional repulsion effects that have previously been reported for simple, low-level features. (PsycInfo Database Record (c) 2026 APA, all rights reserved).