Synthetic Face Adaptation Reveals Neural Tuning A Logan, G Loffler, G E Gordon |
|---|
Visual Neuroscience Research Group, Glasgow Caledonian University, United Kingdom
|
| Introduction: Prolonged viewing of a face can influence the appearance of subsequently-viewed faces. We aimed to quantify the magnitude of face adaptation for unfamiliar synthetic faces as a function of face identity and face distinctiveness. Methods: Observers adapted to synthetic faces with specific identity and distinctiveness. Face discrimination sensitivity against a mean face was assessed for the adapted identity (congruent condition) and novel identities (incongruent). Baseline sensitivity was measured with a low-level noise adaptor. Results: Face discrimination sensitivity was unchanged by adaptation to the mean face. Equally, incongruent conditions did not differ from baseline. Congruent face discrimination thresholds, however, were significantly elevated. The magnitude of this elevation was related to the distinctiveness of the adapting face, ranging monotonically from 1.37 (least distinctive adaptor) to 2.38 (most distinctive). Conclusions: Synthetic face adaptation resulted in an identity-specific reduction in sensitivity. Adaptation did not transfer between identities. The magnitude of the adaptation in the congruent-identity condition showed a monotonic dependence on face distinctiveness: the more distinct the adaptor, the stronger the adapting effect. This suggests a norm-based representation of faces with neural populations tuned to face identity and distinctiveness that respond with increasing magnitude as faces become more different from the mean. |
| Up Home |
|---|