The Role Eyes Play In Face Recognition And The Familiarity Effect

Eyes play an important role in face recognition.Some researchers believe that the eye provides diagnostic information for face recognition and the diagnosticity of the eye relative to other facial features determines the special role of the eye in face processing.Other researchers believe that the eye has priority in the coding of face structure and it is the "anchor point" of holistic processing.To test these two theories,we conducted the study 1: the role of the eye in face recognition.Some studies have pointed out that the role of the eye in face recognition will change with the familiarity of the face.In order to explore the influence of face familiarity on the role of the eye in face recognition,we conducted the study 2: the influence of face familiarity to the role of eyes in face recognition.In the study 1,a new experimental paradigm combined gaze-contingent morphing approach and variable viewing position paradigm was used.According to the fixation position of the subjects,the entire face was divided into the central region of fixation and the peripheral region of fixation.We compared the differences in sensitivity for the changes of central region and peripheral region when the subjects' fixation located at the eyes and mouth.Experiment 1 changed the fixation location(eyes and mouth)and compared the accuracy of detection of changes in different information of the face(the central region of fixation and the peripheral region of fixation).As a result,it was found that when looking at the eyes,compared to looking at the mouth,the participants' detection of changes in the peripheral areas was better,but there was no difference in the detection of changes in the central area.Experiment 2 examined the effect of face orientation on changes detection in different regions when fixation location changed.Experiment 2a measured the accuracy of the detection of changes when subjects processed the peripheral regions under different face orientations and different fixation locations.The results showed that when faces were presented upright,compared with mouth as fixation location,when fixation located at eyes,subjects were more sensitive to changes in the peripheral region,however,there was no significant difference when faces are inverted.Experiment 2b measured the accuracy of the detection of changes when subjects processed the central regions under different face orientations and different fixation locations.The results showed that when faces were presented upright,compared with eye as fixation location,when fixation located at mouth,subjects were more sensitive to changes in the centre region,however,there was no significant difference when faces are inverted.In summary,this study supports that the role of the eye in face recognition is as an anchor point for the holistic processing of the face.Study 2 compares celebrity faces and stranger faces that have been matched by face attractiveness,and examines the influence of face familiarity on the role of eyes in face recognition.Experiment 3 also adopts the new experimental paradigm that combines gaze-contingent morphing approach and variable viewing position paradigm to measured the accuracy of the detection of changes in different regions(the central region of fixation and the peripheral region of fixation)of the face when fixation lies in different regions(eyes and mouth)of the face with different familiarity.The results were as follows:(1)When looking at the peripheral region,no matter the face is familiar or unfamiliar,the accuracy of discrimination when looking at the eyes is significantly greater than that of the mouth.(2)When looking at the central region,under unfamiliar face conditions,the accuracy of discrimination in the mouth is significantly greater than that of the eyes;under familiar face conditions,the difference in the accuracy of discrimination between eyes and mouth was not significant.In order to complement Experiment 3,Experiment 4 directly used face parts to compare differences in discrimination between eyes and mouths of familiar faces and unfamiliar faces.Experiment 4a compared celebrity faces.As a result,the accuracy of eye discrimination was significantly greater than that of the mouth;experiment 4b compared strange faces.As a result,the difference between the accuracy of eye discrimination and the mouth was not significant.This shows that participants are more sensitive to eyes of celebrity face than stranger faces.In summary,we have found that(1)when looking at the eye in face recognition(compared with looking at the mouth),the change in information in the central region is not as sensitive to information changes in the peripheral region,and this difference depends on the orientation of the face(2)People are more sensitive to eyes of celebrity faces than eyes of strange faces.These findings support the role of the eye in face recognition as an anchor point for the holistic processing of the face,indicating that the increase in familiarity of the face enhances the role of the eye as a diagnostic feature of the face.The eye region has an important position in providing the idiosyncratic of a person's face variability.