Unconsciously Triggered Conflict Adaptation

In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition.     

Self-Relevance Appraisal Influences Facial Reactions to Emotional Body Expressions

People display facial reactions when exposed to others'' emotional expressions, but exactly what mechanism mediates these facial reactions remains a debated issue. In this study, we manipulated two critical perceptual features that contribute to determining the significance of others'' emotional expressions: the direction of attention (toward or away from the observer) and the intensity of the emotional display. Electromyographic activity over the corrugator muscle was recorded while participants observed videos of neutral to angry body expressions. Self-directed bodies induced greater corrugator activity than other-directed bodies; additionally corrugator activity was only influenced by the intensity of anger expresssed by self-directed bodies. These data support the hypothesis that rapid facial reactions are the outcome of self-relevant emotional processing.     

Sex Differences in the Rapid Detection of Emotional Facial Expressions

Background

Previous studies have shown that females and males differ in the processing of emotional facial expressions including the recognition of emotion, and that emotional facial expressions are detected more rapidly than are neutral expressions. However, whether the sexes differ in the rapid detection of emotional facial expressions remains unclear.

Methodology/Principal Findings

We measured reaction times (RTs) during a visual search task in which 44 females and 46 males detected normal facial expressions of anger and happiness or their anti-expressions within crowds of neutral expressions. Anti-expressions expressed neutral emotions with visual changes quantitatively comparable to normal expressions. We also obtained subjective emotional ratings in response to the facial expression stimuli. RT results showed that both females and males detected normal expressions more rapidly than anti-expressions and normal-angry expressions more rapidly than normal-happy expressions. However, females and males showed different patterns in their subjective ratings in response to the facial expressions. Furthermore, sex differences were found in the relationships between subjective ratings and RTs. High arousal was more strongly associated with rapid detection of facial expressions in females, whereas negatively valenced feelings were more clearly associated with the rapid detection of facial expressions in males.

Conclusion

Our data suggest that females and males differ in their subjective emotional reactions to facial expressions and in the emotional processes that modulate the detection of facial expressions.     

Influence of Supraliminal Reward Information on Unconsciously Triggered Response Inhibition

Although executive functions (e.g., response inhibition) are often thought to interact consciously with reward, recent studies have demonstrated that they can also be triggered by unconscious stimuli. Further research has suggested a close relationship between consciously and unconsciously triggered response inhibition. To date, however, the effect of reward on unconsciously triggered response inhibition has not been explored. To address this issue, participants in this study performed runs of a modified Go/No-Go task during which they were exposed to both high and low value monetary rewards presented both supraliminally and subliminally. Participants were informed that they would earn the reward displayed if they responded correctly to each trial of the run. According to the results, when rewards were presented supraliminally, a greater unconsciously triggered response inhibition was observed for high-value rewards than for low-value rewards. In contrast, when rewards were presented subliminally, no enhanced unconsciously triggered response inhibition was observed. Results revealed that supraliminal and subliminal rewards have distinct effects on unconsciously triggered response inhibition. These findings have important implications for extending our understanding of the relationship between reward and response inhibition.     

Facial EMG Responses to Emotional Expressions Are Related to Emotion Perception Ability

Although most people can identify facial expressions of emotions well, they still differ in this ability. According to embodied simulation theories understanding emotions of others is fostered by involuntarily mimicking the perceived expressions, causing a “reactivation” of the corresponding mental state. Some studies suggest automatic facial mimicry during expression viewing; however, findings on the relationship between mimicry and emotion perception abilities are equivocal. The present study investigated individual differences in emotion perception and its relationship to facial muscle responses - recorded with electromyogram (EMG) - in response to emotional facial expressions. N° = °269 participants completed multiple tasks measuring face and emotion perception. EMG recordings were taken from a subsample (N° = °110) in an independent emotion classification task of short videos displaying six emotions. Confirmatory factor analyses of the m. corrugator supercilii in response to angry, happy, sad, and neutral expressions showed that individual differences in corrugator activity can be separated into a general response to all faces and an emotion-related response. Structural equation modeling revealed a substantial relationship between the emotion-related response and emotion perception ability, providing evidence for the role of facial muscle activation in emotion perception from an individual differences perspective.     

Neural Correlates of Conflict Control on Facial Expressions with A Flanker Paradigm

Conflict control is an important cognitive control ability and it is also crucial for human beings to execute conflict control on affective information. To address the neural correlates of cognitive control on affective conflicts, the present study recorded event-related potentials (ERPs) during a revised Eriksen Flanker Task. Participants were required to indicate the valence of the central target expression while ignoring the flanker expressions in the affective congruent condition, affective incongruent condition and neutral condition (target expressions flanked by scramble blocks). Behavioral results manifested that participants exhibited faster response speed in identifying neutral target face when it was flanked by neutral distractors than by happy distractors. Electrophysiological results showed that happy target expression induced larger N2 amplitude when flanked by sad distractors than by happy distractors and scramble blocks during the conflict monitoring processing. During the attentional control processing, happy target expression induced faster P3 response when it was flanked by happy distractors than by sad distractors, and sad target expression evoked larger P3 amplitude when it was flanked by happy distractors comparing with sad distractors. Taken together, the current findings of temporal dynamic of brain activity during cognitive control on affective conflicts shed light on the essential relationship between cognitive control and affective information processing.     

Event-related Potential Study of the Effects of Emotional Facial Expressions on Task Performance in Euthymic Bipolar Patients

There appears to be a significant disconnect between symptomatic and functional recovery in bipolar disorder (BD). Some evidence points to interepisode cognitive dysfunction. We tested the hypothesis that some of this dysfunction was related to emotional reactivity in euthymic bipolar subjects may effect cognitive processing. A modification of emotional gender categorization oddball task was used. The target was gender (probability 25%) of faces with negative, positive, and neutral emotional expression. The experiment had 720 trials (3 blocks × 240 trials each). Each stimulus was presented for 150 ms, and the EEG/ERP responses were recorded for 1,000 ms. The inter-trial interval was varied in 1,100–1,500 ms range to avoid expectancy effects. Task took about 35 min to complete. There were 9 BD and 9 control subjects matched for age and gender. Reaction time (RT) was globally slower in BD subjects. The centro-parietal amplitudes at N170 and N200, and P200 and P300 were generally smaller in the BD group compared to controls. Latency was shorter to neutral and negative targets in BD. Frontal P200 amplitude was higher to emotional negative facial non-targets in BD subjects. The frontal N200 in response to positive facial emotion was less negative in BD subjects. The frontal P300 of BD subjects was lower to emotionally neutral targets. ERP responses to facial emotion in BD subjects varied significantly from normal controls. These variations are consistent with the common depressive symptomology seen in long term studies of bipolar subjects.     

The Enfacement Illusion Is Not Affected by Negative Facial Expressions

Enfacement is an illusion wherein synchronous visual and tactile inputs update the mental representation of one’s own face to assimilate another person’s face. Emotional facial expressions, serving as communicative signals, may influence enfacement by increasing the observer’s motivation to understand the mental state of the expresser. Fearful expressions, in particular, might increase enfacement because they are valuable for adaptive behavior and more strongly represented in somatosensory cortex than other emotions. In the present study, a face was seen being touched at the same time as the participant’s own face. This face was either neutral, fearful, or angry. Anger was chosen as an emotional control condition for fear because it is similarly negative but induces less somatosensory resonance, and requires additional knowledge (i.e., contextual information and social contingencies) to effectively guide behavior. We hypothesized that seeing a fearful face (but not an angry one) would increase enfacement because of greater somatosensory resonance. Surprisingly, neither fearful nor angry expressions modulated the degree of enfacement relative to neutral expressions. Synchronous interpersonal visuo-tactile stimulation led to assimilation of the other’s face, but this assimilation was not modulated by facial expression processing. This finding suggests that dynamic, multisensory processes of self-face identification operate independently of facial expression processing.     

Neuroticism Delays Detection of Facial Expressions

The rapid detection of emotional signals from facial expressions is fundamental for human social interaction. The personality factor of neuroticism modulates the processing of various types of emotional facial expressions; however, its effect on the detection of emotional facial expressions remains unclear. In this study, participants with high- and low-neuroticism scores performed a visual search task to detect normal expressions of anger and happiness, and their anti-expressions within a crowd of neutral expressions. Anti-expressions contained an amount of visual changes equivalent to those found in normal expressions compared to neutral expressions, but they were usually recognized as neutral expressions. Subjective emotional ratings in response to each facial expression stimulus were also obtained. Participants with high-neuroticism showed an overall delay in the detection of target facial expressions compared to participants with low-neuroticism. Additionally, the high-neuroticism group showed higher levels of arousal to facial expressions compared to the low-neuroticism group. These data suggest that neuroticism modulates the detection of emotional facial expressions in healthy participants; high levels of neuroticism delay overall detection of facial expressions and enhance emotional arousal in response to facial expressions.     

The Modulation of Mimicry by Ethnic Group-Membership and Emotional Expressions

Mimicry has been ascribed affiliative functions. In three experiments, we used a newly developed social-affective mimicry task (SAMT) to investigate mimicry´s modulation by emotional facial expressions (happy, angry) and ethnic group-membership (White in-group, Black out-group). Experiment 1 established the main consistent effect across experiments, which was enhanced mimicry to angry out-group faces compared to angry in-group faces. Hence the SAMT was useful for experimentally investigating the modulation of mimicry. Experiment 2 demonstrated that these effects were not confounded by general aspects of response conflict, as a Simon task resulted in different response patterns than the SAMT. Experiment 2 and pooled analysis of Experiments 1 and 2 also corroborated the finding of enhanced mimicry to angry out-group faces. Experiment 3 tested whether this effect was related to perceptions of threat, by framing angry persons as physically threatening, or not. Selective enhancement of mimicry to out-group persons framed as physically threatening confirmed this hypothesis. Further support for the role of threat was derived from implicit measures showing, in all experiments, that black persons were more strongly associated with threat. Furthermore, enhanced mimicry was consistently related to response facilitation in the execution of congruent movements. This suggests that mimicry acted as a social congruency signal. Our findings suggest that mimicry may serve as an appeasement signal in response to negative affiliative intent. This extends previous models of mimicry, which have predominantly focused on its role in reciprocating affiliation. It suggests that mimicry might not only be used to maintain and establish affiliative bonds, but also to ameliorate a negative social situation.     

Shadows Alter Facial Expressions of Noh Masks

Background

A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers’ recognition of the emotional expressions.

Methodology/Principal Findings

In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images.

Conclusions/Significance

Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa’s smile. They also agree with the aesthetic principle of Japanese traditional art “yugen (profound grace and subtlety)”, which highly appreciates subtle emotional expressions in the darkness.     

Social Use of Facial Expressions in Hylobatids

Non-human primates use various communicative means in interactions with others. While primate gestures are commonly considered to be intentionally and flexibly used signals, facial expressions are often referred to as inflexible, automatic expressions of affective internal states. To explore whether and how non-human primates use facial expressions in specific communicative interactions, we studied five species of small apes (gibbons) by employing a newly established Facial Action Coding System for hylobatid species (GibbonFACS). We found that, despite individuals often being in close proximity to each other, in social (as opposed to non-social contexts) the duration of facial expressions was significantly longer when gibbons were facing another individual compared to non-facing situations. Social contexts included grooming, agonistic interactions and play, whereas non-social contexts included resting and self-grooming. Additionally, gibbons used facial expressions while facing another individual more often in social contexts than non-social contexts where facial expressions were produced regardless of the attentional state of the partner. Also, facial expressions were more likely ‘responded to’ by the partner’s facial expressions when facing another individual than non-facing. Taken together, our results indicate that gibbons use their facial expressions differentially depending on the social context and are able to use them in a directed way in communicative interactions with other conspecifics.     

Alexithymia and the Processing of Emotional Facial Expressions (EFEs): Systematic Review, Unanswered Questions and Further Perspectives

Alexithymia is characterized by difficulties in identifying, differentiating and describing feelings. A high prevalence of alexithymia has often been observed in clinical disorders characterized by low social functioning. This review aims to assess the association between alexithymia and the ability to decode emotional facial expressions (EFEs) within clinical and healthy populations. More precisely, this review has four main objectives: (1) to assess if alexithymia is a better predictor of the ability to decode EFEs than the diagnosis of clinical disorder; (2) to assess the influence of comorbid factors (depression and anxiety disorder) on the ability to decode EFE; (3) to investigate if deficits in decoding EFEs are specific to some levels of processing or task types; (4) to investigate if the deficits are specific to particular EFEs. Twenty four studies (behavioural and neuroimaging) were identified through a computerized literature search of Psycinfo, PubMed, and Web of Science databases from 1990 to 2010. Data on methodology, clinical characteristics, and possible confounds were analyzed. The review revealed that: (1) alexithymia is associated with deficits in labelling EFEs among clinical disorders, (2) the level of depression and anxiety partially account for the decoding deficits, (3) alexithymia is associated with reduced perceptual abilities, and is likely to be associated with impaired semantic representations of emotional concepts, and (4) alexithymia is associated with neither specific EFEs nor a specific valence. These studies are discussed with respect to processes involved in the recognition of EFEs. Future directions for research on emotion perception are also discussed.     

Paedomorphic Facial Expressions Give Dogs a Selective Advantage

How wolves were first domesticated is unknown. One hypothesis suggests that wolves underwent a process of self-domestication by tolerating human presence and taking advantage of scavenging possibilities. The puppy-like physical and behavioural traits seen in dogs are thought to have evolved later, as a byproduct of selection against aggression. Using speed of selection from rehoming shelters as a proxy for artificial selection, we tested whether paedomorphic features give dogs a selective advantage in their current environment. Dogs who exhibited facial expressions that enhance their neonatal appearance were preferentially selected by humans. Thus, early domestication of wolves may have occurred not only as wolf populations became tamer, but also as they exploited human preferences for paedomorphic characteristics. These findings, therefore, add to our understanding of early dog domestication as a complex co-evolutionary process.     

Body Actions Change the Appearance of Facial Expressions

Perception, cognition, and emotion do not operate along segregated pathways; rather, their adaptive interaction is supported by various sources of evidence. For instance, the aesthetic appraisal of powerful mood inducers like music can bias the facial expression of emotions towards mood congruency. In four experiments we showed similar mood-congruency effects elicited by the comfort/discomfort of body actions. Using a novel Motor Action Mood Induction Procedure, we let participants perform comfortable/uncomfortable visually-guided reaches and tested them in a facial emotion identification task. Through the alleged mediation of motor action induced mood, action comfort enhanced the quality of the participant’s global experience (a neutral face appeared happy and a slightly angry face neutral), while action discomfort made a neutral face appear angry and a slightly happy face neutral. Furthermore, uncomfortable (but not comfortable) reaching improved the sensitivity for the identification of emotional faces and reduced the identification time of facial expressions, as a possible effect of hyper-arousal from an unpleasant bodily experience.     

Time Perception and Dynamics of Facial Expressions of Emotions

Two experiments were run to examine the effects of dynamic displays of facial expressions of emotions on time judgments. The participants were given a temporal bisection task with emotional facial expressions presented in a dynamic or a static display. Two emotional facial expressions and a neutral expression were tested and compared. Each of the emotional expressions had the same affective valence (unpleasant), but one was high-arousing (expressing anger) and the other low-arousing (expressing sadness). Our results showed that time judgments are highly sensitive to movements in facial expressions and the emotions expressed. Indeed, longer perceived durations were found in response to the dynamic faces and the high-arousing emotional expressions compared to the static faces and low-arousing expressions. In addition, the facial movements amplified the effect of emotions on time perception. Dynamic facial expressions are thus interesting tools for examining variations in temporal judgments in different social contexts.     

Serotonin Transporter Gene-Linked Polymorphism Affects Detection of Facial Expressions

Previous studies have demonstrated that the serotonin transporter gene-linked polymorphic region (5-HTTLPR) affects the recognition of facial expressions and attention to them. However, the relationship between 5-HTTLPR and the perceptual detection of others'' facial expressions, the process which takes place prior to emotional labeling (i.e., recognition), is not clear. To examine whether the perceptual detection of emotional facial expressions is influenced by the allelic variation (short/long) of 5-HTTLPR, happy and sad facial expressions were presented at weak and mid intensities (25% and 50%). Ninety-eight participants, genotyped for 5-HTTLPR, judged whether emotion in images of faces was present. Participants with short alleles showed higher sensitivity (d′) to happy than to sad expressions, while participants with long allele(s) showed no such positivity advantage. This effect of 5-HTTLPR was found at different facial expression intensities among males and females. The results suggest that at the perceptual stage, a short allele enhances the processing of positive facial expressions rather than that of negative facial expressions.