Modulation of facial reactions to avatar emotional faces by nonconscious competition priming

Social conditioning and extinction paradigm: a translational study in virtual reality

In human beings, experiments investigating fear conditioning with social stimuli are rare. The current study aims at translating an animal model for social fear conditioning (SFC) to a human sample using an operant SFC paradigm in virtual reality. Forty participants actively (using a joystick) approached virtual male agents that served as conditioned stimuli (CS). During the acquisition phase, unconditioned stimuli (US), a combination of an air blast (5 bar, 10 ms) and a female scream (95 dB, 40 ms), were presented when participants reached a defined proximity to the agent with a contingency of 75% for CS+ agents and never for CS- agents. During the extinction and the test phases, no US was delivered. Outcome variables were pleasantness ratings and physiological reactions in heart rate (HR) and fear-potentiated startle. Additionally, the influence of social anxiety, which was measured with the Social Phobia Inventory scale, was evaluated. As expected after the acquisition phase the CS+ was rated clearly less pleasant than the CS-. This difference vanished during extinction. Furthermore, the HR remained high for the CS+, while the HR for the CS- was clearly lower after than before the acquisition. Furthermore, a clear difference between CS+ and CS- after the acquisition indicated successful conditioning on this translational measure. Contrariwise no CS+/CS- differences were observed in the physiological variables during extinction. Importantly, at the generalization test, higher socially fearful participants rated pleasantness of all agents as low whereas the lower socially fearful participants rated pleasantness as low only for the CS+. SFC was successfully induced and extinguished confirming operant conditioning in this SFC paradigm. These findings suggest that the paradigm is suitable to expand the knowledge about the learning and unlearning of social fears. Further studies should investigate the operant mechanisms of development and treatment of social anxiety disorder.

Antecedents and Consequences of Mimicry: A Naturalistic Interaction Approach

Mimicking, that is showing the same nonverbal behaviour as one's interaction partner, is related to trait Affiliation, but there are no previous investigations on its relations to broader concepts of personality. In this study, personality was assessed in terms of the Big Five and the two interpersonal dimensions Affiliation and Dominance. Dyads of unacquainted participants completed a task, several of their behaviours being coded every 10 s. Moreover, the interactants were instructed either to cooperate or to compete, and their performance and liking were measured. Using multilevel modelling, mimicry coefficients were estimated (Level 1) and predicted from personality (Level 2) and the situational context (Level 3). In addition, performance and being liked were predicted from mimicry and the context. Mimicry turned out to be widespread, being predicted by personality traits for some behaviours. In turn, mimicry predicted performance and being liked, some of these effects also depending on the context. Copyright © 2015 European Association of Personality Psychology

Autistic traits modulate frontostriatal connectivity during processing of rewarding faces

Deficits in facial mimicry have been widely reported in autism. Some studies have suggested that these deficits are restricted to spontaneous mimicry and do not extend to volitional mimicry. We bridge these apparently inconsistent observations by testing the impact of reward value on neural indices of mimicry and how autistic traits modulate this impact. Neutral faces were conditioned with high and low reward. Subsequently, functional connectivity between the ventral striatum (VS) and inferior frontal gyrus (IFG) was measured while neurotypical adults (n = 30) watched happy expressions made by these conditioned faces. We found greater VS-IFG connectivity in response to high reward vs low reward happy faces. This difference was negatively proportional to autistic traits, suggesting that reduced spontaneous mimicry of social stimuli seen in autism, may be related to a failure in the modulation of the mirror system by the reward system rather than a circumscribed deficit in the mirror system.

Virtual faces expressing emotions: an initial concomitant and construct validity study

BACKGROUND

Facial expressions of emotions represent classic stimuli for the study of social cognition. Developing virtual dynamic facial expressions of emotions, however, would open-up possibilities, both for fundamental and clinical research. For instance, virtual faces allow real-time Human-Computer retroactions between physiological measures and the virtual agent.

OBJECTIVES

The goal of this study was to initially assess concomitants and construct validity of a newly developed set of virtual faces expressing six fundamental emotions (happiness, surprise, anger, sadness, fear, and disgust). Recognition rates, facial electromyography (zygomatic major and corrugator supercilii muscles), and regional gaze fixation latencies (eyes and mouth regions) were compared in 41 adult volunteers (20 ♂, 21 ♀) during the presentation of video clips depicting real vs. virtual adults expressing emotions.

RESULTS

Emotions expressed by each set of stimuli were similarly recognized, both by men and women. Accordingly, both sets of stimuli elicited similar activation of facial muscles and similar ocular fixation times in eye regions from man and woman participants.

CONCLUSION

Further validation studies can be performed with these virtual faces among clinical populations known to present social cognition difficulties. Brain-Computer Interface studies with feedback-feedforward interactions based on facial emotion expressions can also be conducted with these stimuli.

Bridging the mechanical and the human mind: spontaneous mimicry of a physically present android

The spontaneous mimicry of others' emotional facial expressions constitutes a rudimentary form of empathy and facilitates social understanding. Here, we show that human participants spontaneously match facial expressions of an android physically present in the room with them. This mimicry occurs even though these participants find the android unsettling and are fully aware that it lacks intentionality. Interestingly, a video of that same android elicits weaker mimicry reactions, occurring only in participants who find the android "humanlike." These findings suggest that spontaneous mimicry depends on the salience of humanlike features highlighted by face-to-face contact, emphasizing the role of presence in human-robot interaction. Further, the findings suggest that mimicry of androids can dissociate from knowledge of artificiality and experienced emotional unease. These findings have implications for theoretical debates about the mechanisms of imitation. They also inform creation of future robots that effectively build rapport and engagement with their human users.

When mirroring is both simple and "smart": how mimicry can be embodied, adaptive, and non-representational

The concept of mirroring has become rather ubiquitous. One of the most fundamental empirical and theoretical debates within research on mirroring concerns the role of mental representations: while some models argue that higher-order representational mechanisms underpin most cases of mirroring, other models argue that they only moderate a primarily non-representational process. As such, even though research on mirroring—along with its neural substrates, including the putative mirror neuron system—has grown tremendously, so too has confusion about what it actually means to “mirror”. Using recent research on spontaneous imitation, we argue that flexible mirroring effects can be fully embodied and dynamic—even in the absence of higher-order mental representations. We propose that mirroring can simply reflect an adaptive integration and utilization of cues obtained from the brain, body, and environment, which is especially evident within the social context. Such a view offers reconciliation among both representational and non-representational frameworks in cognitive neuroscience, which will facilitate revised interpretations of modern (and seemingly divergent) findings on when and how these embodied mirroring responses are employed.

The perception and mimicry of facial movements predict judgments of smile authenticity

The mechanisms through which people perceive different types of smiles and judge their authenticity remain unclear. Here, 19 different types of smiles were created based on the Facial Action Coding System (FACS), using highly controlled, dynamic avatar faces. Participants observed short videos of smiles while their facial mimicry was measured with electromyography (EMG) over four facial muscles. Smile authenticity was judged after each trial. Avatar attractiveness was judged once in response to each avatar’s neutral face. Results suggest that, in contrast to most earlier work using static pictures as stimuli, participants relied less on the Duchenne marker (the presence of crow’s feet wrinkles around the eyes) in their judgments of authenticity. Furthermore, mimicry of smiles occurred in the Zygomaticus Major, Orbicularis Oculi, and Corrugator muscles. Consistent with theories of embodied cognition, activity in these muscles predicted authenticity judgments, suggesting that facial mimicry influences the perception of smiles. However, no significant mediation effect of facial mimicry was found. Avatar attractiveness did not predict authenticity judgments or mimicry patterns.

Social exclusion induces early-stage perceptual and behavioral changes in response to social cues

Social exclusion is so aversive that it causes broad cognitive and behavioral changes to regulate the individual's belonging status. The present study examined whether such changes also occur at early neural or automatic behavioral levels in response to social cues. Event-related brain potentials (ERPs) and facial electromyograms (EMGs) were recorded during a task in which participants viewed smiling, disgusted, and neutral faces after experiencing social exclusion or inclusion. Social exclusion was manipulated using a simple ball-tossing game (Cyberball), and need threat was assessed after the game. We found that zygomaticus major muscle activity, which reflects facial mimicry, was larger in response to smiling faces after exclusion than after inclusion. In addition, P1 amplitude, which reflects visual attention, was larger for disgusted faces than for neutral faces following social exclusion. N170 amplitude, which reflects structural encoding of the face, was correlated with heightened need threat. These findings demonstrate that social exclusion induces immediate and rapid changes in attention, perception, and automatic behavior. These findings reflect the rapid and primary regulation of belonging.

How interpersonal power affects empathic accuracy: differential roles of mentalizing vs. mirroring?

Empathic accuracy (EA)—the correct assessment of the affective states and thoughts of a social partner—affects social behavior and the outcome of interpersonal interactions. Growing evidence has shown that interpersonal power of a perceiver affects EA when assessing a target. This picture, however, is not obvious; there is evidence supporting both the idea that power can improve EA or impair it. Moreover, the mechanisms through which high power individuals are more (or less) accurate at reading others' minds are unknown. The present article provides a new perspective on the power-EA link by investigating how two core abilities involved in EA, mentalizing and mirroring, can explain when and how power is related to EA. The inclusion of findings from neuroimaging studies on mentalizing and mirroring adds a cognitive neuroscience perspective to the power-EA research that has traditionally been conducted in a social psychological framework. The extent to which a given EA-test requires mentalizing or mirroring and the way power affects both of them could explain the contrasting findings. In addition, the analysis of the neural substrates of mentalizing and mirroring may provide new insight into the relationship between power and EA.

Emotional mimicry as social regulation

Emotional mimicry is the imitation of the emotional expressions of others. According to the classic view on emotional mimicry (the Matched Motor Hypothesis), people mimic the specific facial movements that comprise a discrete emotional expression. However, little evidence exists for the mimicry of discrete emotions; rather, the extant evidence supports only valence-based mimicry. We propose an alternative Emotion Mimicry in Context view according to which emotional mimicry is not based on mere perception but rather on the interpretation of signals as emotional intentions in a specific context. We present evidence for the idea that people mimic contextualized emotions rather than simply expressive muscle movements. Our model postulates that (implicit or explicit) contextual information is needed for emotional mimicry to take place. It takes into account the relationship between observer and expresser, and suggests that emotional mimicry depends on this relationship and functions as a social regulator.

Emotional mimicry in social context: the case of disgust and pride

A recent review on facial mimicry concludes that emotional mimicry is less ubiquitous than has been suggested, and only occurs in interactions that are potentially affiliative (see Hess and Fischer, in revision). We hypothesize that individuals do not mimic facial expressions that can be perceived as offensive, such as disgust, and mimic positive emotion displays, but only when the context is affiliative (i.e., with intimates). Second, we expect that in spontaneous interactions not mimicry, but empathic feelings with the other predict the accurateness of emotion recognition. Data were collected in a pseudo-experimental setting, during an event organized for subscribers of a large Dutch women's magazine. One woman (expresser) was exposed to two emotional stimuli (i.e., a vile smell, a compliment) in order to evoke disgust and pride respectively. Another woman (observer: intimate or stranger) was sitting opposite of her. We collected self-report measures on emotions and empathy, and coded facial expressions of disgust and smiling on the basis of FACS. The results show that participants do not mimic disgust. In contrast, smiles displayed after the vile smell and the compliment were mimicked, but only among intimates. We also found that self-reported empathy and not mimicry is related to the recognition of disgust. These findings are discussed in the light of a Social Contextual view on emotional mimicry.

Electromyographic responses to emotional facial expressions in 6-7year olds: a feasibility study

Preliminary studies have demonstrated that school-aged children (average age 9-10years) show mimicry responses to happy and angry facial expressions. The aim of the present study was to assess the feasibility of using facial electromyography (EMG) as a method to study facial mimicry responses in younger children aged 6-7years to emotional facial expressions of other children. Facial EMG activity to the presentation of dynamic emotional faces was recorded from the corrugator, zygomaticus, frontalis and depressor muscle in sixty-one healthy participants aged 6-7years. Results showed that the presentation of angry faces was associated with corrugator activation and zygomaticus relaxation, happy faces with an increase in zygomaticus and a decrease in corrugator activation, fearful faces with frontalis activation, and sad faces with a combination of corrugator and frontalis activation. This study demonstrates the feasibility of measuring facial EMG response to emotional facial expressions in 6-7year old children.

The role of testosterone in social interaction

Although animal researchers established the role of testosterone as a 'social hormone' decades ago, the investigation of its causal influence on human social behaviors has only recently begun. Here, we review and discuss recent studies showing the causal effects of testosterone on social interactions in animals and humans, and outline the basic neurobiological mechanisms that might underlie these effects. Based on these recent findings, we argue that the role of testosterone in human social behavior might be best understood in terms of the search for, and maintenance of, social status.