A meta-analysis was conducted to compare perceptions of Duchenne smiles, smiles that include activation of the cheek raiser muscle that creates crow's feet around the eyes, with perceptions of non-Duchenne smiles, smiles without cheek raiser activation. In addition to testing the overall effect, moderator analyses were conducted to test how methodological, stimulus-specific and perceiver-specific differences between studies predicted the overall effect size. The meta-analysis found that, overall, Duchenne smiles and people producing Duchenne smiles are rated more positively (i.e., authentic, genuine, (...) real, attractive, trustworthy) than non-Duchenne smiles and people producing non-Duchenne smiles. The difference between Duchenne and non-Duchenne smiles was greater when the stimuli were videos rather than photographs, when smiles were elicited naturally rather than through posing paradigms and when Duchenne and non-Duchenne smiles were not matched for intensity of the lip corner puller in addition to other perceiver and methodological moderators. (shrink)

We report two experimental studies of human perceptions of robotic facial expressions while systematically varying context effects and the cultural background of subjects (n = 93). Except for Fear, East Asian and Western subjects were not significantly different in recognition rates, and, while Westerners were better at judging affect from mouth movement alone, East Asians were not any better at judging affect based on eye/brow movement alone. Moreover, context effects appeared capable of over-riding such cultural differences, most notably for Fear. (...) The results seem to run counter to previous theories of cultural differences in facial expression based on emoticons and eye fixation patterns. We connect this to broader research in cognitive science – suggesting the findings support a dynamical systems view of social cognition as an emergent phenomenon. The results here suggest that, if we can induce appropriate context effects, it may be possible to createculture-neutral modelsof robots and affective interaction. (shrink)

Most experimental studies of facial expression processing have used static stimuli (photographs), yet facial expressions in daily life are generally dynamic. In its original photographic format, the Karolinska Directed Emotional Faces (KDEF) has been frequently utilized. In the current study, we validate a dynamic version of this database, the KDEF-dyn. To this end, we applied animation between neutral and emotional expressions (happy, sad, angry, fearful, disgusted, and surprised; 1,033-ms unfolding) to 40 KDEF models, with morphing software. Ninety-six human observers categorized (...) the expressions of the resulting 240 video-clip stimuli, and automated face analysis assessed the evidence for 6 expressions and 20 facial action units (AUs) at 31 intensities. Low-level image properties (luminance, signal-to-noise ratio, etc.) and other purely perceptual factors (e.g., size, unfolding speed) were controlled. Human recognition performance (accuracy, efficiency, and confusions) patterns were consistent with prior research using static and other dynamic expressions. Automated assessment of expressions and AUs was sensitive to intensity manipulations. Significant correlations emerged between human observers’ categorization and automated classification. The KDEF-dyn database aims to provide a balance between experimental control and ecological validity for research on emotional facial expression processing. The stimuli and the validation data are available to the scientific community. (shrink)

ABSTRACTDynamic changes in emotional expressions are a valuable source of information in social interactions. As the expressive behaviour of a person changes, the inferences drawn from the behaviour may also change. Here, we test the possibility that dynamic changes in emotional expressions affect person perception in terms of stable trait attributions. Across three experiments, we examined perceivers’ inferences about others’ personality traits from changing emotional expressions. Expressions changed from one emotion to another emotion, allowing us to disentangle potential primacy, recency, (...) and averaging effects. Drawing on three influential models of person perception, we examined perceptions of dominance and affiliation, competence and warmth, and dominance and trustworthiness. A strong recency effect was consistently found across all trait judgments, that is, the end emotion of dynamic expressions had a strong impact on t... (shrink)

We report two experimental studies of human perceptions of robotic facial expressions while systematically varying context effects and the cultural background of subjects (n = 93). Except for Fear, East Asian and Western subjects were not significantly different in recognition rates, and, while Westerners were better at judging affect from mouth movement alone, East Asians were not any better at judging affect based on eye/brow movement alone. Moreover, context effects appeared capable of over-riding such cultural differences, most notably for Fear. (...) The results seem to run counter to previous theories of cultural differences in facial expression based on emoticons and eye fixation patterns. We connect this to broader research in cognitive science – suggesting the findings support a dynamical systems view of social cognition as an emergent phenomenon. The results here suggest that, if we can induce appropriate context effects, it may be possible to createculture-neutral modelsof robots and affective interaction. (shrink)

Drawing on research reviewed in this special section, the present article discusses how various contextual factors impact on production and decoding of emotion-related facial activity. Although emotion-related variables often contribute to activation of prototypical “emotion expressions” and perceivers can often infer emotional meanings from these facial configurations, neither process is invariant or direct. Many facial movements are directed towards or away from events in the shared environment, and their effects depend on these relational orientations. Facial activity is not only a (...) medium for descriptive representation of internal affective states, but also a means of adjusting to, and operating on, external objects, and of influencing other people’s appraisals of those objects. (shrink)

Smiles that vary in muscular configuration also vary in how they are perceived. Previous research suggests that “Duchenne smiles,” indicated by the combined actions of the orbicularis oculi and the zygomaticus major muscles, signal enjoyment. This research has compared perceptions of Duchenne smiles with non-Duchenne smiles among individuals voluntarily innervating or inhibiting the orbicularis oculi muscle. Here we used a novel set of highly controlled stimuli: photographs of patients taken before and after receiving botulinum toxin treatment for crow’s feet lines (...) that selectively paralyzed the lateral orbicularis oculi muscle and removed visible lateral eye wrinkles, to test perception of smiles. Smiles in which the orbicularis muscle was active were rated as more felt, spontaneous, intense, and happier. Post treatment patients looked younger, although not more attractive. We discuss the potential implications of these findings within the context of emotion science and clinical research on botulinum toxin. (shrink)

ABSTRACTThere is substantial evidence to suggest that deafness is associated with delays in emotion understanding, which has been attributed to delays in language acquisition and opportunities to converse. However, studies addressing the ability to recognise facial expressions of emotion have produced equivocal findings. The two experiments presented here attempt to clarify emotion recognition in deaf children by considering two aspects: the role of motion and the role of intensity in deaf children’s emotion recognition. In Study 1, 26 deaf children were (...) compared to 26 age-matched hearing controls on a computerised facial emotion recognition task involving static and dynamic expressions of 6 emotions. Eighteen of the deaf and 18 age-matched hearing controls additionally took part in Study 2, involving the presentation of the same 6 emotions at varying intensities. Study 1 showed that deaf children’s emotion recognition was better in the dynamic rather than static condition, whereas the hearing children sh... (shrink)

Smiles provide information about a social partner’s affect and intentions during social interaction. Although always encountered within a specific situation, the influence of contextual information on smile evaluation has not been widely investigated. Moreover, little is known about the reciprocal effect of smiles on evaluations of their accompanying situations. In this research, we assessed how different smile types and situational contexts affected participants’ social evaluations. In Study 1, 85 participants rated reward, affiliation, and dominance smiles embedded within either enjoyable, polite, (...) or negative (unpleasant) situations. Context had a strong effect on smile ratings, such that smiles in enjoyable situations were rated as more genuine and joyful, as well as indicating less superiority than those in negative situations. In Study 2, 200 participants evaluated the situations that these smiles were perceived within (rather than the smiles themselves). Although situations paired with reward (vs. affiliation) smiles tended to be rated more positively, this effect was absent for negative situations. Ultimately, the findings point toward a reciprocal relationship between smiles and contexts, whereby the face influences evaluations of the situation and vice versa. (shrink)

Atypical emotion interpretation has been widely reported in individuals with borderline personality disorder ; however, empirical studies reported mixed results so far. We suggest that discrepancies in observations of emotion interpretation by iBPD can be explained by biases related to their fear of rejection and abandonment, i.e., the three moral emotions of anger, disgust, and contempt. In this study, we hypothesized that iBPD would show a higher tendency to correctly interpret these three displays of social rejection and attribute more negative (...) valence. A total of 28 inpatient iBPDs and 28 healthy controls were asked to judge static and dynamic facial expressions in terms of emotions, valence, and self-reported arousal evoked by the observed faces. Our results partially confirmed our expectations. The iBPD correctly interpreted the three unambiguous moral emotions. Contempt, a complex emotion with a difficulty in recognizing facial expressions, was recognized better by iBPD than by healthy controls. All negative emotions were judged more negatively by iBPD than by controls, but no difference was observed in the neutral or positive emotion. Alexithymia and anxiety trait and state levels were controlled in all analyses. (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)

ABSTRACTThe present study describes the development and validation of a facial expression database comprising five different horizontal face angles in dynamic and static presentations. The database includes twelve expression types portrayed by eight Japanese models. This database was inspired by the dimensional and categorical model of emotions: surprise, fear, sadness, anger with open mouth, anger with closed mouth, disgust with open mouth, disgust with closed mouth, excitement, happiness, relaxation, sleepiness, and neutral. The expressions were validated using emotion classification and Affect (...) Grid rating tasks [Russell, Weiss, & Mendelsohn, 1989. Affect Grid: A single-item scale of pleasure and arousal. Journal of Personality and Social Psychology, 57, 493–502]. The results indicate that most of the expressions were recognised as the intended emotions and could systematically represent affective valence and arousal. Furthermore, face angle and facial motion information influenced emot... (shrink)

For human interaction, it is important to understand what emotional state others are in. Especially the observation of faces aids us in putting behaviours into context and gives insight into emotions and mental states of others. Detecting whether someone is nervous, a form of state anxiety, is such an example as it reveals a person’s familiarity and contentment with the circumstances. With recent developments in computer vision we developed behavioural nervousness models to show which time-varying facial cues reveal whether someone (...) is nervous in an interview setting. The facial changes, reflecting a state of anxiety, led to more visual exposure and less chemosensory (taste and olfaction) exposure. However, experienced observers had difficulty picking up these changes and failed to detect nervousness levels accurately therewith. This study highlights humans’ limited capacity in determining complex emotional states but at the same time provides an automated model that can assist us in achieving fair assessments of so far unexplored emotional states. (shrink)

The accurate recognition of emotion is important for interpersonal interaction and when navigating our social world. However not all facial displays reflect the emotional experience currently being felt by the expresser. Indeed faces express both genuine and posed displays of emotion. In this article, we summarise the importance of motion for the recognition of face identity before critically outlining the role of dynamic information in determining facial expressions and distinguishing between genuine and posed expressions of emotion. We propose that both (...) dynamic information and face familiarity may modulate our ability to determine whether an expression is genuine or not. Finally, we consider the shared role for dynamic information across different face recognition tasks and the wider impact of face familiarity on determining genuine from posed expressions during real-world interactions. (shrink)

Temporal dynamics have been increasingly recognized as an important component of facial expressions. With the need for appropriate stimuli in research and application, a range of databases of dynamic facial stimuli has been developed. The present article reviews the existing corpora and describes the key dimensions and properties of the available sets. This includes a discussion of conceptual features in terms of thematic issues in dataset construction as well as practical features which are of applied interest to stimulus usage. To (...) identify the most influential sets, we further examine their citation rates and usage frequencies in existing studies. General limitations and implications for emotion research are noted and future directions for stimulus generation are outlined. (shrink)

For more than a century expressions have been approached as bidimensional, static, instantaneous, self-contained, well-defined, and universal signals. These assumptions are starting to be empirically reconsidered: this special section of Emotion Review includes reviews on the physical, social, and cultural dynamics of expressions, and on the complex ways in which, throughout the lifespan, facial behavior and emotion are perceived and categorized by primates’ and humans’ brain. All these advances are certainly paving the way for new exciting approaches to facial behavior (...) more likely to strike an appropriate balance between description and explanation. (shrink)