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. 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 distractors that differed only in their emotional expression. Following search, we probed the perceptual representation of the target face using a 2-alternative forced choice task where participants reported 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 perceptual representations of complex, higher-level stimuli to increase the perceptual distinctiveness between targets and distractors in support of selection, mirroring attentional repulsion effects that have previously been reported for simple, low-level features.