Does Categorical Facial Expression Perception Exists In Ensemble Coding An ERP Study

Facial expression is an important social message that conveys our emotions.we can perceive a large number of facial expressions in short time.The time consumed is not a summation of every facial expression recognition spending and the perceived emotions are not the mixed emotions induced by each facial expression.Mean emotion is extracted from facial expression set along dimensions of valence and intensity.It is finally recognized as an average expression.The ensemble coding of facial expressions is called ensemble perception.Facial expressions are artificially divided into different categories.Whether or not ensemble perception can be classified as facial expression? After ensemble coding,does facial expressions remain their characters of holistic and analytic perception? This study try to answer these questions.At the same time,the difference between ensemble coding of facial expressions and processing of facial expressions is also being focused.This study uses mixed methods of event-related potentials(ERP)and behavioral measurement.Experiment 1 is a behavioral experiment,facial expressions occurs during a rapid serial visual Presentation.It was verified that participants can extract the average emotion.I found an advantage effect while recognizing happy faces.Experiment 2 is an ERP experiment,based on the adaptation effect to investigate whether the ensemble perception of a sequence of faces exists,and whether there is a categorical relationship between average expression and facial expression.It was found that experiment modulation happens on three ERP components of EPN,and LPP and the face adaptation effect expected before experiment was not found.Combined with the results of behavioral research,it is found that there is no categorical relationship between average expression and facial expression.Experiment 3 is a behavioral experiment,facial expression set occurs at the same time.It was verified that participants can extract the average emotion.I also found an advantage effect while recognizing happy faces in experiment3.Experiment 4 is an ERP experiment,based on the adaptation effect to investigate whether the ensemble perception of a sequence of faces exists,and whether there is a categorical relationship between average expression and facial expression.In Experiment 4,I only found one clear difference on LPP for participants in experiment and control conditions and the face adaptation effect expected before experiment was not found either.There is no categorical relationship between average expression and facial expression in Experiment 4.The first two experiments and the latter two experiments respectively focused on two different forms of ensemble coding.Our results in all experiments suggest that:1.This study supports the existence of ensemble perception of facial expressions in temporal and spatial.2.The facial expression and average expression are not the same kind of information and the ensemble perception of the face is not an average of face morphing.3.The ensemble coding of face mainly retains the emotional information of the face and loses parts of the configural information and low-level feature information.