Positive serial dependences of social characteristics perception in group context are similar but different

The visual system can efficiently process a great amount of visual information, which surpasses computational capacity. One key mechanism for this is ensemble coding, where summary statistical information can be extracted. Another important one is positive serial dependence, where responses to the current stimulus are systematically biased toward the previous one. While these mechanisms are demonstrated to co-occur for fundamental stimuli such as orientations, do these two mechanisms extend to social characteristics of faces, and are the effects consistent across different social characteristics? Here, in this study, we investigated three commonly tested social characteristics (attractiveness, trustworthiness, and dominance). Results from Experiment 1 suggest that positive serial dependence influences the social characteristics perception of face groups. Furthermore, we observe differences in how positive serial dependence affects group perception versus individual face processing, indicating that the perception of group contexts may be dissociated from its components. We further tested with inverted faces in Experiment 2. The results demonstrate that positive serial dependence in group perception for social characteristics of the face relies on both local features and holistic/configural processing from faces. In general, the current study expanded our understanding of serial face perception and perception of face groups.