Competition effects of threatening faces in social anxiety

Threatening faces involuntarily grab attention in socially anxious individuals. It is unclear, however, whether attention capture is at the expense of concurrent visual processing. The current study examined the perceptual cost effects of viewing fear-relevant stimuli (threatening faces) relative to a concurrent change-detection task. Steady-state visual evoked potentials (ssVEPs) were used to separate the neural response to 2 fully overlapping types of stimuli flickering at different frequencies: Task-irrelevant facial expressions (angry, neutral, happy) were overlaid with a task-relevant Gabor patch stream, which required a response to rare phase reversals. Groups of 17 high and 17 low socially anxious observers were recruited through online prescreening of 849 students. A prominent competition effect of threatening faces was observed solely in elevated social anxiety: When an angry face, relative to a neutral or happy face, served as a distractor, heightened ssVEP amplitudes were seen at the tagging frequency of that facial expression. Simultaneously, the ssVEP evoked by the task-relevant Gabor grating was reliably diminished compared with conditions with neutral or happy distractor faces. Thus, threatening faces capture and hold low-level perceptual resources in viewers symptomatic for social anxiety at the cost of a concurrent primary task. It is important to note that this competition in lower tier visual cortex was maintained throughout the viewing period and was unaccompanied by competition effects on behavioral performance. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Neural correlates of attention to emotional facial expressions in dysphoria

The present study investigated whether dysphoric individuals have a difficulty in disengaging attention from negative stimuli and/or reduced attention to positive information. Sad, neutral and happy facial stimuli were presented in an attention-shifting task to 18 dysphoric and 18 control participants. Reaction times to neutral shapes (squares and diamonds) and the event-related potentials to emotional faces were recorded. Dysphoric individuals did not show impaired attentional disengagement from sad faces or facilitated disengagement from happy faces. Right occipital lateralisation of P100 was absent in dysphoric individuals, possibly indicating reduced attention-related sensory facilitation for faces. Frontal P200 was largest for sad faces among dysphoric individuals, whereas controls showed larger amplitude to both sad and happy as compared with neutral expressions, suggesting that dysphoric individuals deployed early attention to sad, but not happy, expressions. Importantly, the results were obtained controlling for the participants' trait anxiety. We conclude that at least under some circumstances the presence of depressive symptoms can modulate early, automatic stages of emotional processing.     

特质焦虑在面部表情前注意加工阶段的影响：来自ERP的证据

为探讨高特质焦虑者在前注意阶段对情绪刺激的加工模式以明确其情绪偏向性特点, 本研究采用偏差-标准反转Oddball范式探讨了特质焦虑对面部表情前注意加工的影响。结果发现: 对于低特质焦虑组, 悲伤面孔所诱发的早期EMMN显著大于快乐面孔, 而对于高特质焦虑组, 快乐和悲伤面孔所诱发的早期EMMN差异不显著。并且, 高特质焦虑组的快乐面孔EMMN波幅显著大于低特质焦虑组。结果表明, 人格特质是影响面部表情前注意加工的重要因素。不同于普通被试, 高特质焦虑者在前注意阶段对快乐和悲伤面孔存在相类似的加工模式, 可能难以有效区分快乐和悲伤情绪面孔。     

An ERP study on facial expression of emotion: comparison of linguistic and visual semantic decoding

The present research compared the semantic information processing of linguistic stimuli with semantic elaboration of nonlinguistic facial stimuli. To explore brain potentials (ERPs, event-related potentials) related to decoding facial expressions and the effect of semantic valence of the stimulus, we analyzed data for 20 normal subjects (M age = 23.6 yr., SD = 0.2). Faces with three basic emotional expressions (fear, happiness, and sadness from the 1976 Ekman and Friesen database), with three semantically anomalous expressions (with respect to their emotional content), and the neutral stimuli (face without an emotional content) were presented in a random order. Differences in peak amplitude of ERP were observed later for anomalous expressions compared with congruous expressions. In fact, the results demonstrated that the emotional anomalous faces elicited a higher negative peak at about 360 msec., distributed mainly over the posterior sites. The observed electrophysiological activity may represent specific cognitive processing underlying the comprehension of facial expressions in detection of semantic anomaly. The evidence is in favour of comparability of this negative deflection with the N400 ERP effect elicited by linguistic anomalies.     

Emotions in word and face processing: Early and late cortical responses

Recent research suggests that emotion effects in word processing resemble those in other stimulus domains such as pictures or faces. The present study aims to provide more direct evidence for this notion by comparing emotion effects in word and face processing in a within-subject design. Event-related brain potentials (ERPs) were recorded as participants made decisions on the lexicality of emotionally positive, negative, and neutral German verbs or pseudowords, and on the integrity of intact happy, angry, and neutral faces or slightly distorted faces. Relative to neutral and negative stimuli both positive verbs and happy faces elicited posterior ERP negativities that were indistinguishable in scalp distribution and resembled the early posterior negativities reported by others. Importantly, these ERP modulations appeared at very different latencies. Therefore, it appears that similar brain systems reflect the decoding of both biological and symbolic emotional signals of positive valence, differing mainly in the speed of meaning access, which is more direct and faster for facial expressions than for words.     

Identification of angry faces in the attentional blink

According to cognitive and neural theories of emotion, attentional processing of innate threat stimuli, such as angry facial expressions, is prioritised over neutral stimuli. To test this hypothesis, the present study used a modified version of the rapid serial visual presentation (RSVP) paradigm to investigate the effect of emotional face stimuli on the attentional blink (AB). The target stimuli were schematic faces which depicted threatening (angry), positive or neutral facial expressions. Results showed that performance accuracy was enhanced (i.e., the AB was reduced) on trials in which the second target was an angry face, rather than a neutral face. Results extend previous research by demonstrating that angry faces reduce the AB, and that this effect is found for schematic facial expressions. These findings further support the proposal that, when there is competition for attentional resources, threat stimuli are given higher priority in processing compared with non-threatening stimuli.     

The role of spatial attention in the processing of facial expression: An ERP study of rapid brain responses to six basic emotions

To investigate the time course of emotional expression processing, we recorded ERP responses to stimulus arrays containing neutral versus angry, disgusted, fearful, happy, sad, or surprised faces. In one half of the experiment, the task was to discriminate emotional and neutral facial expressions. Here, an enhanced early frontocentral positivity was elicited in response to emotional as opposed to neutral faces, followed by a broadly distributed positivity and an enhanced negativity at lateral posterior sites. These emotional expression effects were very similar for all six basic emotional expressions. In the other half of the experiment, attention was directed away from the faces toward a demanding perceptual discrimination task. Under these conditions, emotional expression effects were completely eliminated, demonstrating that brain processes involved in the detection and analysis of facial expression require focal attention. The face-specific N170 component was unaffected by any emotional expression, supporting the hypothesis that structural encoding and expression analysis are independent processes.     

Hostility‐ and gender‐related differences in oscillatory responses to emotional facial expressions

Hostility is associated with biases in the perception of emotional facial expressions, such that ambiguous or neutral expressions tend to be perceived as threatening or angry. In this study, the effects of hostility and gender on the perception of angry, neutral, and happy faces and on the oscillatory dynamics of cortical responses elicited by these presentations were investigated using time–frequency decomposition by means of wavelet transforms. Feelings of hostility predisposed subjects to perceive happy and neutral faces as less friendly. This effect was more pronounced in women. In hostile subjects, presentation of emotional facial expressions also evoked stronger posterior synchronization in the theta and diminished desynchronization in the alpha band. This may signify a prevalence of emotional responding over cognitive processing. These effects were also more pronounced in females. Hostile females, but not hostile males, additionally showed a widespread synchronization in the alpha band. This synchronization is tentatively explained as a manifestation of inhibitory control which is present in aggressive females, but not in aggressive males. Aggr. Behav. 35:502–513, 2009. © 2009 Wiley‐Liss, Inc.     

Detecting emotional faces and features in a visual search paradigm: are faces special?

In 2 experiments, participants were presented schematic faces with emotional expressions (threatening, friendly) in a neutral-faces context or neutral expressions in an emotional-faces context. These conditions were compared with detection performance in displays containing key features of emotional faces not forming the perceptual gestalt of a face. Supporting the notion of a threat detection advantage, Experiment 1 found that threatening faces were faster detected than friendly faces, whereas no difference emerged between the corresponding feature conditions. Experiment 2 increased task difficulty with a backward masking procedure and found corresponding results. In neither of the studies was the threat detection advantage associated with reduced accuracy. However, features were, in general, detected faster than faces when task difficulty was high.     

Emotion processing in children who do and do not stutter: An ERP study of electrocortical reactivity and regulation to peer facial expressions

PurposeEvent-related brain potentials (ERPs) were used to investigate the neural correlates of emotion processing in 5- to 8-year-old children who do and do not stutter.MethodsParticipants were presented with an audio contextual cue followed by images of threatening (angry/fearful) and neutral facial expressions from similarly aged peers. Three conditions differed in audio-image pairing: neutral context-neutral expression (neutral condition), negative context-threatening expression (threat condition), and reappraisal context-threatening expression (reappraisal condition). These conditions reflected social stimuli that are ecologically valid to the everyday life of children.ResultsP100, N170, and late positive potential (LPP) ERP components were elicited over parietal and occipital electrodes. The threat condition elicited an increased LPP mean amplitude compared to the neutral condition across our participants, suggesting increased emotional reactivity to threatening facial expressions. In addition, LPP amplitude decreased during the reappraisal condition— evidence of emotion regulation. No group differences were observed in the mean amplitude of ERP components between children who do and do not stutter. Furthermore, dimensions of childhood temperament and stuttering severity were not strongly correlated with LPP elicitation.ConclusionThese findings are suggestive that, at this young age, children who stutter exhibit typical brain activation underlying emotional reactivity and regulation to social threat from peer facial expressions.     

Mapping the time course of the positive classification advantage: An ERP study

The aim of the present study was to investigate the time course of the positive advantage in the expression classification of faces by recording event-related potentials (ERPs). Although neutral faces were classified more quickly than either happy or sad faces, a significant positive classification advantage (PCA)—that is, faster classification for happy than for sad faces—was found. For ERP data, as compared with sad faces, happy faces elicited a smaller N170 and a larger posterior N2 component. The P3 was modulated by facial expressions with higher amplitudes and shorter latencies for both happy and neutral stimuli than for sad stimuli, and the reaction times were significantly correlated with the amplitude and latency of the P3. Overall, these data showed robust PCA in expression classification, starting when the stimulus has been recognized as a face revealed by the N170 component.     

Preferential processing of threatening facial expressions using the repetition blindness paradigm

Background: Neuroanatomical evidence suggests that the human brain has dedicated pathways to rapidly process threatening stimuli. This processing bias for threat was examined using the repetition blindness (RB) paradigm. RB (i.e., failure to report the second instance of an identical stimulus rapidly following the first) has been established for words, objects and faces but not, to date, facial expressions. Methods: 78 (Study 1) and 62 (Study 2) participants identified repeated and different, threatening and non-threatening emotional facial expressions in rapid serial visual presentation (RSVP) streams. Results: In Study 1, repeated facial expressions produced more RB than different expressions. RB was attenuated for threatening expressions. In Study 2, attenuation of RB for threatening expressions was replicated. Additionally, semantically related but non-identical threatening expressions reduced RB relative to non-threatening stimuli. Conclusions: These findings suggest that the threat bias is apparent in the temporal processing of facial expressions, and expands the RB paradigm by demonstrating that identical facial expressions are susceptible to the effect.     

Morphed facial expressions elicited a N400 ERP effect: A domain‐specific semantic module?

Previous studies have revealed that decoding of facial expressions is a specific component of face comprehension and that semantic information might be processed separately from the basic stage of face perception. In order to explore event-related potentials (ERPs) related to recognition of facial expressions and the effect of the semantic content of the stimulus, we analyzed 20 normal subjects. Faces with three prototypical emotional expressions (fear, happiness, and sadness) and with three morphed expressions were presented in random order. The neutral stimuli represented the control condition. Whereas ERP profiles were similar with respect to an early negative ERP (N170), differences in peak amplitude were observed later between incongruous (morphed) expressions and congruous (prototypical) ones. In fact, the results demonstrated that the emotional morphed faces elicited a negative peak at about 360 ms, mainly distributed over the posterior site. The electrophysiological activity observed may represent a specific cognitive process underlying decoding of facial expressions in case of semantic anomaly detection. The evidence is in favor of the similarity of this negative deflection with the N400 ERP effect elicited in linguistic tasks. A domain-specific semantic module is proposed to explain these results.     

On the automaticity of emotion processing in words and faces: event-related brain potentials evidence from a superficial task

The degree to which emotional aspects of stimuli are processed automatically is controversial. Here, we assessed the automatic elicitation of emotion-related brain potentials (ERPs) to positive, negative, and neutral words and facial expressions in an easy and superficial face-word discrimination task, for which the emotional valence was irrelevant. Both emotional words and facial expressions impacted ERPs already between 50 and 100 ms after stimulus onset, possibly reflecting rapid relevance detection. Following this initial processing stage only emotionality in faces but not in words was associated with an early posterior negativity (EPN). Therefore, when emotion is irrelevant in a task which requires superficial stimulus analysis, automatically enhanced sensory encoding of emotional content appears to occur only for evolutionary prepared emotional stimuli, as reflected in larger EPN amplitudes to faces, but not to symbolic word stimuli.     

Fearful expressions enhance recognition memory: electrophysiological evidence

Facial expressions play a key role in affective and social behavior. However, the temporal dynamics of the brain responses to emotional faces remain still unclear, in particular an open question is at what stage of face processing expressions might influence encoding and recognition memory. To try and answer this question we recorded the event-related potentials (ERPs) elicited in an old/new recognition task. A novel aspect of the present design was that whereas faces were presented during the study phase with either a happy, fearful or neutral expression, they were always neutral during the memory retrieval task. The ERP results showed three main findings: An enhanced early fronto-central positivity for faces encoded as fearful, both during the study and the retrieval phase. During encoding subsequent memory (Dm effect) was influenced by emotion. At retrieval the early components P100 and N170 were modulated by the emotional expression of the face at the encoding phase. Finally, the later ERP components related to recognition memory were modulated by the previously encoded facial expressions. Overall, these results suggest that face recognition is modulated by top-down influences from brain areas associated with emotional memory, enhancing encoding and retrieval in particular for fearful emotional expressions.     

Dynamic facial expressions of emotion induce representational momentum

Two experiments were conducted to explore whether representational momentum (RM) emerges in the perception of dynamic facial expression and whether the velocity of change affects the size of the effect. Participants observed short morphing animations of facial expressions from neutral to one of the six basic emotions. Immediately afterward, they were asked to select the last images perceived. The results of the experiments revealed that the RM effect emerged for dynamic facial expressions of emotion: The last images of dynamic stimuli that an observer perceived were of a facial configuration showing stronger emotional intensity than the image actually presented. The more the velocity increased, the more the perceptual image of facial expression intensified. This perceptual enhancement suggests that dynamic information facilitates shape processing in facial expression, which leads to the efficient detection of other people's emotional changes from their faces.     

Conserved evolutionary history for quick detection of threatening faces

Humans quickly recognize threats such as snakes and threatening faces, suggesting that human ancestors evolved specialized visual systems to detect biologically relevant threat stimuli. Although non-human primates also detect snakes quickly, it is unclear whether primates share the efficient visual systems to process the threatening faces of their conspecifics. Primates may not necessarily process conspecific threats by facial expressions, because threats from conspecifics in natural situations are often accompanied by other cues such as threatening actions (or attacks) and vocal calls. Here, we show a similar threat superiority effect in both humans and macaque Japanese monkeys. In visual search tasks, monkeys and humans both responded to pictures of a threatening face of an unfamiliar adult male monkey among neutral faces faster than to pictures of a neutral face among threatening faces. However, the monkeys’ response times to detect deviant pictures of a non-face stimulus were not slower when it was shown among threat faces than when it was shown among neutral faces. These results provide the first evidence that monkeys have an attentional bias toward the threatening faces of conspecifics and suggest that threatening faces are evolutionarily relevant fear stimuli. The subcortical visual systems in primates likely process not only snakes, but also more general biological threat-relevant stimuli, including threatening conspecific faces.     

知觉与表象过程中不同线索表情的启动效应研究

探讨情绪性面孔的知觉和表象过程中,不同类型线索表情的启动效应,并关注不同类型表情表象难易的差异。选取NimStim数据库中20位演员的愉快、愤怒和中性表情作为启动刺激,随后呈现同一演员不同表情的图片,或通过颜色提示被试对不同表情进行表象,并同时进行表情类型判断。研究发现,情绪性面孔知觉与表象任务中均存在启动效应,之前呈现的线索面孔将会对接下来呈现的相同效价的面孔产生启动效应,对相反效价及中性面孔产生抑制; 在平衡不同类型面孔可能存在的启动效应后,正性、负性及中性表情是同样易于表象的。     

The effect of inducing panic search on the detection of fear-relevant and neutral images

Panic search occurs when the presentation of a fearful facial expression precue, prior to a search display, improves target detection relative to when neutral and positive expressions are used. In the present study, fearful and neutral expressions acted as precues and targets were images of either neutral or threatening animals. It was predicted that detection of a threatening image following a fearful precue would be particularly facilitated. In a first experiment, target detection was better when targets were threatening than neutral, but the predicted cue enhancement did not occur. In a second experiment, when cue type was blocked, participants were particularly facilitated in responding to threatening targets following fearful precues. It is concluded that consistent and repeated exposure to threatening facial expression results in a generalized increase in processing efficiency and that such a state induces a particular facilitation in responding in the presence of threatening targets.     

Emotion regulates attention: The relation between facial configurations,facial emotion,and visual attention

We used threatening, friendly, and neutral schematic facial stimuli, in which three, two, or one feature(s) conveyed emotion, to test the hypothesis that humans preferentially orient attention towards threat, and to examine the relation between facial features, emotional impression, and visual attention. Using a visual search paradigm, participants searched for discrepant faces in arrays of otherwise identical faces. Subsequently they also rated their emotional impression of the involved stimuli. Across four experiments, we found faster and more accurate detection of threatening than friendly faces, even when only one feature conveyed the emotion. Facial features affected both attention and emotion in the rank order eyebrows > mouth > eyes. Finally, the emotional impression of a face predicted its effect on attention.