For thousands of human’s history, we have learned how to fake or hide our genuine feelings and emotion to our surrounding folks intentionally or unconsciously. It is an irony that this is what we call emotion intelligence to get more interests, show our politeness, tackle the dilemma, or deal with many other complicated situations. Posed smiles are one of the most common faked expressions in our daily life. Indeed, it is a challenge for computer vision system to recognize genuine from (...) posed smile of an individual, not even for human brains sometimes. Recently, an interesting work by Guo et al.(Guo, et al., 2018) employed computer vision techniques to investigate the potential differences in duration, intensity, speed, symmetry of the lip corners, and certain irregularities between genuine and posed smiles based on the UvA-NEMO Smile Database. The results are quite rewarding since they found that genuine smiles were correlated with higher onset, offset, apex, and total durations, as well as offset displacement, and Irregularity-b, compared with posed smiles. In addition, posed smiles were correlated with higher onset and offset Speeds, Irregularity-a, Symmetry-a, and Symmetry-d.We can’t agree with the saying that only a handful of studies on the dynamic features of facial expressions have been conducted due to the lack of user-friendly analytic tools. For the past decades, hundreds of studies focused on dynamic features of facial expressions (Ko, 2018, Sandbach, et al., 201... (shrink)

Smiles play an important role in social perception. However, it is unclear whether a similar role is played by static facial features associated with smiles. In dental science, maxillary dental protrusions increase the baring of the teeth and thus produce partial facial features of a smile even when the individual is not choosing to smile, whereas mandibular dental protrusions do not. We conducted three experiments to assess whether individuals ascribe positive evaluations to these facial features, which are not genuine emotional (...) expressions. In Experiment 1, participants viewed facial photographs of maxillary and mandibular protrusions and indicated the smiling and emotional status of the faces. The results showed that, while no difference was observed in participants’ perception of the presence of a smile across both types of dental protrusion, participants felt more positive to faces with maxillary than mandibular protrusions. In Experiment 2, participants completed an Implicit Association Test test measuring implicit attitudes toward faces with maxillary vs. mandibular protrusions. The results showed that participants had more positive attitude toward faces with maxillary than mandibular protrusions. In Experiment 3, individuals with either maxillary or mandibular protrusions completed the same IAT test to assess whether any preference would be affected by in-group/out-group preferences. The results showed both groups had more positive attitudes toward faces with maxillary protrusion, indicating that this preference is independent of the group effect. These findings suggest that facial features associated with smiles are viewed positively in social situations. We discuss this in terms of the social-function account. (shrink)

Facial information is a powerful channel for human-to-human communication. Characteristically, faces can be defined as biological objects that are four-dimensional (4D) patterns, whereby they have concurrently a spatial structure as well as temporal dynamics. The spatial characteristics of facial objects possess three dimensions (3D), namely breadth, height and importantly, depth. The temporal properties of facial objects are defined by how a 3D facial structure evolves dynamically over time; where time is referred to as the fourth dimension (4D). Our entire perspective (...) of another’s face, whether it be social, affective or cognitive perceptions, is therefore built on a combination of 3D and 4D visual cues. Counterintuitively, over the past few decades of experimental research in psychology, facial stimuli have largely been presented to participants as a spatial pattern that has been flattened into two dimensions (2D), while remaining largely static. The following review aims to advance and update facial researchers, on the recent revolution in computer-generated, realistic 4D facial models produced from real-life human subjects. We delve in-depth to summarize recent studies which have utilized facial stimuli that possess 3D structural cues (geometry and depth) and 4D temporal cues (3D structure + dynamic viewpoint and movement). In sum, we have found that higher-order perceptions such as identity, gender, ethnicity, emotion and personality, are critically influenced by the 4D characteristics embedded within natural human faces. In future, it is recommended that facial stimuli incorporate the 4D space-time perspective with the proposed time-resolved methods. (shrink)