Face 3-dimensioal Representation:the Effects Of Familiarity,viewpoint Difference,and Facial Region On Face Matching

In the three-dimensional world,people see other people’s faces from different angles.How do people construct three-dimensional representations of other people’s identities from the different two-dimensional images of other people’s faces in the retina?Some researchers believe that faces of different familiarity are represented in different ways in the mind.The representation of unfamiliar faces is "view-dependent",while the representation of familiar faces is "view-independent".The results showed that the change of viewpoint significantly impaired the recognition of unfamiliar faces,but had little effect on the recognition of familiar faces.Some studies have found that different regions play different roles in face recognition.Compared with other regions,the eye region is more important,and the region information used in face processing is also affected by familiarity.This suggests that the eye region plays an important role in face representation.In the process of viewpoint change,the regional information presented by the face will also change.Therefore,regional information is likely to change the impact of viewpoint on face recognition.In this paper,two studies were conducted to investigate the differences between familiar and unfamiliar faces in three-dimensional representation and the role of regions in familiar and unfamiliar faces three-dimensional representation.Study 1 included three experiments.Experiment 1 examined whether the viewpoint effect was different between familiar and unfamiliar faces.In this study,participants were asked to judge whether two faces with the same viewpoint belonged to the same person before and after the two faces were presented,and the differences of recognition performance between familiar faces(classmates who had been exposed to for 3 months)and unfamiliar faces from different viewpoint were investigated by using delayed matching paradigm.The results showed that the performance of familiar face recognition was significantly higher than that of unfamiliar face recognition.Beyond a certain viewpoint,familiar faces were affected by viewpoint,while unfamiliar faces were barely affected by viewpoint.In Experiment 2,participants were asked to determine whether two faces presented with different viewpoint belonged to the same person or not.In Experiment 2,participants were asked to determine whether two faces presented with different viewpoint belonged to the same person.The results showed that the performance of familiar face recognition was significantly higher than that of unfamiliar face recognition,and the viewpoint difference effect of familiar face was significantly worse than that of unfamiliar face.In Experiment 3,the simultaneous matching paradigm was used to explore whether the perception difference between familiar faces and unfamiliar faces still existed.The results showed that the performance of familiar face recognition was significantly higher than that of unfamiliar face recognition,and the viewpoint difference effect of familiar face was significantly worse than that of unfamiliar face.Study 2 consisted of three experiments.Experiment 4 investigated whether theviewpoint difference effect changed after the face area was blocked.In this study,the delayed matching paradigm was used to determine whether two faces from different viewpoints belonged to the same person or not,so as to investigate the change of the recognition performance of unfamiliar faces with different viewpoints when the eyes or mouth area was blocked.The results showed that eye occlusion impaired face recognition,mouth occlusion did not damage face recognition,eye occlusion significantly reduced the viewpoint difference effect,mouth occlusion did not change the viewpoint difference effect.In Experiment 5,the delayed matching paradigm was used.In Experiment 5,the participants were asked to determine whether two faces with different viewpoints were the same person in the face area obscured by a matched face.The effects of different viewpoints on the recognition of familiar faces and unfamiliar faces were investigated after the eyes area or mouth area was obscured by a matched face.The results showed that both familiar face recognition and unfamiliar face recognition were impaired by eye occlusion,while the mouth occlusion had no effect on familiar face recognition.In Experiment 6,the simultaneous matching paradigm was used to explore the difference effect of familiar and unfamiliar faces on the perceptual level after blocking eyes or mouth.The results showed that the viewpoint difference effect did not change significantly in both the occluded eye area and the occluded mouth area under the familiar condition,but changed in the occluded eye area but did not change in the occluded mouth area under the unfamiliar face condition.In this study,we found that viewpoint effect of unfamiliar faces was small and viewpoint different effect was large,while viewpoint effect of familiar faces was large and viewpoint difference effect was small,suggesting that the increase of face experience enhanced the three-dimensional representation of faces.This study also found that for both familiar and unfamiliar faces,occlusion of the eye region reduced the viewpoint different effect,and occlusion of the mouth regoin did not reduce the Angle of view difference effect,suggesting that the eyes have regional selectivity in the three-dimensional representation of faces,which enriches the theoretical hypothesis of regional selectivity in face processing.