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.     

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.     

More than just another face in the crowd: superior detection of threatening facial expressions in children and adults

Threatening facial expressions can signal the approach of someone or something potentially dangerous. Past research has established that adults have an attentional bias for angry faces, visually detecting their presence more quickly than happy or neutral faces. Two new findings are reported here. First, evidence is presented that young children share this attentional bias. In five experiments, young children and adults were asked to find a picture of a target face among an array of eight distracter faces. Both age groups detected threat‐relevant faces – angry and frightened – more rapidly than non‐threat‐relevant faces (happy and sad). Second, evidence is presented that both adults and children have an attentional bias for negative stimuli overall. All negative faces were detected more quickly than positive ones in both age groups. As the first evidence that young children exhibit the same superior detection of threatening facial expressions as adults, this research provides important support for the existence of an evolved attentional bias for threatening stimuli.     

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.     

The timeline of threat processing in repressors: more evidence for early vigilance and late avoidance

Evidence is mixed concerning whether individuals with a repressive coping style can actually selectively avoid threatening stimuli. Recent research (Calvo & Eysenck, 2000) on repressors’ threat processing suggests that it is necessary to take into account the timeline of this bias. A spontaneous trait inference paradigm was used here to test the hypothesis that repressors would, relative to others, be less likely to infer unfavorable and threatening traits. However, if pressured to make trait inferences quickly, it was predicted that they would be less likely than others to infer favorable and unthreatening traits. Repressors and nonrepressors were presented with passages that could have supported positive or negative trait inferences. In Study 1, they were asked to respond to trait words as quickly as possible but were not held accountable for doing so. In Study 2, time pressure was increased to capture uncorrected trait inferences. Results indicated that repressors were more likely to make positive trait inferences than others when simply asked to respond quickly. Under time pressure, this bias disappeared. Results point to the importance of taking into account an important moderator between coping style and threat, namely, the stage of processing at which differences in threat processing are being assessed.     

Differential impact of emotional task relevance on three indices of prioritised processing for fearful and angry facial expressions

It is commonly assumed that threatening expressions are perceptually prioritised, possessing the ability to automatically capture and hold attention. Recent evidence suggests that this prioritisation depends on the task relevance of emotion in the case of attention holding and for fearful expressions. Using a hybrid attentional blink (AB) and repetition blindness (RB) paradigm we investigated whether task relevance also impacts on prioritisation through attention capture and perceptual salience, and if these effects generalise to angry expressions. Participants judged either the emotion (relevant condition) or gender (irrelevant condition) of two target facial stimuli (fearful, angry or neutral) imbedded in a stream of distractors. Attention holding and capturing was operationalised as modulation of AB deficits by first target (T1) and second target (T2) expression. Perceptual salience was operationalised as RB modulation. When emotion was task-relevant (Experiment 1; N?=?29) fearful expressions captured and held attention, and were more perceptually salient than neutral expressions. Angry expressions captured attention, but were less perceptually salient and capable of holding attention than fearful and neutral expressions. When emotion was task-irrelevant (Experiment 2; N?=?30), only fearful attention capture and perceptual salience effects remained significant. Our findings highlight the importance for threat-prioritisation research to heed both the type of threat and prioritisation investigated.     

Superior detection of threat-relevant stimuli in infancy

The ability to quickly detect potential threat is an important survival mechanism for humans and other animals. Past research has established that adults have an attentional bias for the detection of threat-relevant stimuli, including snakes and spiders as well as angry human faces. Recent studies have documented that preschool children also detect the presence of threatening stimuli more quickly than various non-threatening stimuli. Here we report the first evidence that this attentional bias is present even in infancy. In two experiments, 8- to 14-month-old infants responded more rapidly to snakes than to flowers and more rapidly to angry than to happy faces. These data provide the first evidence of enhanced visual detection of threat-relevant stimuli in infants and hence offer especially strong support for the existence of a general bias for the detection of threat in humans.     

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。     

The facilitated processing of threatening faces: an ERP analysis

Threatening, friendly, and neutral faces were presented to test the hypothesis of the facilitated perceptual processing of threatening faces. Dense sensor event-related brain potentials were measured while subjects viewed facial stimuli. Subjects had no explicit task for emotional categorization of the faces. Assessing early perceptual stimulus processing, threatening faces elicited an early posterior negativity compared with nonthreatening neutral or friendly expressions. Moreover, at later stages of stimulus processing, facial threat also elicited augmented late positive potentials relative to the other facial expressions, indicating the more elaborate perceptual analysis of these stimuli. Taken together, these data demonstrate the facilitated perceptual processing of threatening faces. Results are discussed within the context of an evolved module of fear (A. Ohman & S. Mineka, 2001).     

Attentional biases and memory for emotional stimuli in men and male rhesus monkeys

We examined attentional biases for social and non-social emotional stimuli in young adult men and compared the results to those of male rhesus monkeys (Macaca mulatta) previously tested in a similar dot-probe task (King et al. in Psychoneuroendocrinology 37(3):396–409, 2012). Recognition memory for these stimuli was also analyzed in each species, using a recognition memory task in humans and a delayed non-matching-to-sample task in monkeys. We found that both humans and monkeys displayed a similar pattern of attentional biases toward threatening facial expressions of conspecifics. The bias was significant in monkeys and of marginal significance in humans. In addition, humans, but not monkeys, exhibited an attentional bias away from negative non-social images. Attentional biases for social and non-social threat differed significantly, with both species showing a pattern of vigilance toward negative social images and avoidance of negative non-social images. Positive stimuli did not elicit significant attentional biases for either species. In humans, emotional content facilitated the recognition of non-social images, but no effect of emotion was found for the recognition of social images. Recognition accuracy was not affected by emotion in monkeys, but response times were faster for negative relative to positive images. Altogether, these results suggest shared mechanisms of social attention in humans and monkeys, with both species showing a pattern of selective attention toward threatening faces of conspecifics. These data are consistent with the view that selective vigilance to social threat is the result of evolutionary constraints. Yet, selective attention to threat was weaker in humans than in monkeys, suggesting that regulatory mechanisms enable non-anxious humans to reduce sensitivity to social threat in this paradigm, likely through enhanced prefrontal control and reduced amygdala activation. In addition, the findings emphasize important differences in attentional biases to social versus non-social threat in both species. Differences in the impact of emotional stimuli on recognition memory between monkeys and humans will require further study, as methodological differences in the recognition tasks may have affected the results.     

Amplification of attentional blink by distress‐related facial expressions: Relationships with alexithymia and affectivity

The present studies aimed to analyse the modulatory effect of distressing facial expressions on attention processing. The attentional blink (AB) paradigm is one of the most widely used paradigms for studying temporal attention, and is increasingly applied to study the temporal dynamics of emotion processing. The aims of this study were to investigate how identifying fear and pain facial expressions (Study 1) and fear and anger facial expressions (Study 2) would influence the detection of subsequent stimuli presented within short time intervals, and to assess the moderating influence of alexithymia and affectivity on this effect. It has been suggested that high alexithymia scorers need more attentional resources to process distressing facial expressions and that negative affectivity increases the AB. We showed that fear, anger and pain produced an AB and that alexithymia moderated it such that difficulty in describing feelings (Study 1) and externally oriented thinking (Study 2) were associated with higher interference after the processing of fear and anger at short time presentations. These studies provide evidence that distressing facial expressions modulate the attentional processing at short time intervals and that alexithymia influences the early attentional processing of fear and anger expressions. Controlling for state affect did not change these conclusions.     

Social anxiety and attentional biases: A top-down contribution?

Selective attention toward threatening facial expressions has been found to precipitate and maintain symptoms of social anxiety. However, the automaticity of this bias is under debate. In the present study, we aimed to test whether top-down (controlled) engagement and disengagement of attention toward threatening faces is associated with social anxiety. This was examined by testing the impact of a secondary working memory (WM) load on attentional biases. In a variation of the dot-probe task, participants’ attention was initially cued to the left or right of fixation before an upright face paired with an inverted face was presented (displaying a disgust or neutral expression), and participants responded to a subsequently presented probe. The task was performed under no-load, low-load (one-digit memory task), and high-load (six-digit memory task) conditions. Social anxiety was not found to be associated with delayed disengagement from threat. However, surprisingly, high social anxiety was associated with an engagement bias away from threat, whereas low social anxiety was associated with a bias toward threat. These results were unaffected by the WM load manipulation. This indicates that engagement with threatening facial expressions has minimal contributions from top-down mechanisms, since it is likely that orienting to facial expressions occurs relatively automatically.     

The effect of spatial frequency information and visual similarity in threat detection

In the current research, we sought to examine the role of spatial frequency on the detection of threat using a speeded visual search paradigm. Participants searched for threat-relevant (snakes or spiders) or non-threat-relevant (frogs or cockroaches) targets in an array of neutral (flowers or mushrooms) distracters, and we measured search performance with images filtered to contain different levels (high and low) of spatial frequency information. The results replicate previous work demonstrating more rapid detection of threatening versus non-threatening stimuli [e.g. LoBue, V. & DeLoache, J. S. (2008). Detecting the snake in the grass: Attention to fear-relevant stimuli by adults and young children. Psychological Science, 19, 284–289. doi:10.1111/j.1467-9280.2008.02081.x]. Most importantly, the results suggest that low spatial frequency or relatively coarse levels of visual information is sufficient for the rapid and accurate detection of threatening stimuli. Furthermore, the results also suggest that visual similarity between the stimuli used in the search tasks plays a significant role in speeded detection. The results are discussed in terms of the theoretical implications for the rapid detection of threat and methodological implications for properly accounting for similarity between the stimuli in visual search studies.     

Memory for dangers past: threat contexts produce more consistent learning than do non-threatening contexts

In earlier work we showed that individuals learn the spatial regularities within contexts and use this knowledge to guide detection of threatening targets embedded in these contexts. While it is highly adaptive for humans to use contextual learning to detect threats, it is equally adaptive for individuals to flexibly readjust behaviour when contexts once associated with threatening stimuli begin to be associated with benign stimuli, and vice versa. Here, we presented face targets varying in salience (threatening or non-threatening) in new or old spatial configurations (contexts) and changed the target salience (threatening to non-threatening and vice versa) halfway through the experiment to examine if contextual learning changes with the change in target salience. Detection of threatening targets was faster in old than new configurations and this learning persisted even after the target changed to non-threatening. However, the same pattern was not seen when the targets changed from non-threatening to threatening. Overall, our findings show that threat detection is driven not only by stimulus properties as theorised traditionally but also by the learning of contexts in which threatening stimuli appear, highlighting the importance of top-down factors in threat detection. Further, learning of contexts associated with threatening targets is robust and speeds detection of non-threatening targets subsequently presented in the same context.     

Attentional biases to threat in social anxiety disorder: time to focus our attention elsewhere?

Background: Cognitive models propose that attentional biases to threat contribute to the maintenance of social anxiety disorder (SAD). However, the specific characteristics of such biases are still object to debate.

Objectives: The current study aimed to disentangle effects of trait and state social anxiety on attention allocation towards social stimuli.

Methods: Participants with SAD (n?=?67) and healthy controls (n?=?62) completed three visual search tasks while their eye movements were recorded. Half of the participants in each group were randomly assigned to a state anxiety induction.

Results: Contrary to our predictions, neither trait nor state social anxiety was associated with a facilitated attention to or a delayed disengagement from threat. However, participants with SAD did show reduced fixation durations for threatening stimuli, indicating an avoidance of threat. Induction of state anxiety led to an increased distractibility by threat.

Conclusions: We suggest that attention allocation in SAD is characterized by an avoidant rather than a vigilant attentional bias. Accordingly, our results contradict previous results that associate SAD with facilitated attention to threat and existing approaches to modify attentional biases, that aim to decrease attention towards threatening stimuli.     

The shape of threat: simple geometric forms evoke rapid and sustained capture of attention

Previous work has indicated that simple geometric shapes underlying facial expressions are capable of conveying emotional meaning. Specifically, a series of studies found that a simple shape, a downward-pointing "V," which is similar to the geometric configuration of the face in angry expressions, is perceived as threatening. A parallel line of research has determined that threatening stimuli more readily capture attention. In five experiments, the authors sought to determine whether this preferential processing was also present for the simple geometric form of a downward-pointing "V." Using a visual search paradigm, across these experiments the authors found that, when embedded in a field of other shapes, downward-pointing V's were detected faster and, in some cases, more accurately than identical shapes pointing upward. These findings indicate that the meaning of threat can be conveyed rapidly with minimal stimulus detail. In addition, in some cases, during trials of homogeneous fields of stimuli, fields of downward-pointing V's led to slower response times, suggesting that this shape's ability to capture attention may also extend to difficulty in disengaging attention as well.     

Attention to Positive and Negative Social-Evaluative Words: Investigating the Effects of Social Anxiety,Trait Anxiety and Social Threat

The study investigated how attention to negative (threatening) and positive social-evaluative words is affected by social anxiety, trait anxiety and the expectation of social threat. High and low socially anxious individuals carried out a modified dot-probe task either while expecting to give a speech or under non-threatening conditions. High socially anxious individuals showed no significant attentional bias towards or away from social-evaluative words. This result significantly contrasted with an identical design that showed avoidance of emotional faces in high socially anxious participants drawn from the same population (Mansell et al ., 1999). Participants who expected to give a speech showed less attentional avoidance of negative and positive social-evaluative words. High trait anxiety was associated with selective attention to negative relative to positive social-evaluative words, consistent with earlier findings of attention to threat cues in high trait-anxious individuals. Implications for designing attention tasks and attentional bias across different dimensions of anxiety are discussed.     

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.     

Context learning for threat detection

It is hypothesised that threatening stimuli are detected better due to their salience or physical properties. However, these stimuli are typically embedded in a rich context, motivating the question whether threat detection is facilitated via learning of contexts in which threat stimuli appear. To address this question, we presented threatening face targets in new or old spatial configurations consisting of schematic faces and found that detection of threatening targets was faster in old configurations. This indicates that individuals are able to learn regularities within visual contexts and use this contextual information to guide detection of threatening targets. Next, we presented threatening and non-threatening face targets embedded in new or old spatial configurations. Detection of threatening targets was facilitated in old configurations, and this effect was reversed for non-threatening targets. Present findings show that detection of threatening targets is driven not only by stimulus properties as theorised traditionally but also by learning of contexts in which threatening stimuli appear. Further, results show that context learning for threatening targets obstructs context learning for non-threatening targets. Overall, in addition to typically emphasised bottom-up factors, our findings highlight the importance of top-down factors such as context and learning in detection of salient, threatening stimuli.     

Information processing bias against emotional facial expressions in social anxiety

The present study examined whether information processing bias against emotional facial expressions is present among individuals with social anxiety. College students with high (high social anxiety group; n  = 26) and low social anxiety (low social anxiety group; n  = 26) performed three different types of working memory tasks: (a) ordering positive and negative facial expressions according to the intensity of emotion; (b) ordering pictures of faces according to age; and (c) ordering geometric shapes according to size. The high social anxiety group performed significantly more poorly than the low social anxiety group on the facial expression task, but not on the other two tasks with the nonemotional stimuli. These results suggest that high social anxiety interferes with processing of emotionally charged facial expressions.