The Role of Emotional Content and Perceptual Saliency During the Programming of Saccades Toward Faces

Previous studies have shown that the human visual system can detect a face and elicit a saccadic eye movement toward it very efficiently compared to other categories of visual stimuli. In the first experiment, we tested the influence of facial expressions on fast face detection using a saccadic choice task. Face-vehicle pairs were simultaneously presented and participants were asked to saccade toward the target (the face or the vehicle). We observed that saccades toward faces were initiated faster, and more often in the correct direction, than saccades toward vehicles, regardless of the facial expressions (happy, fearful, or neutral). We also observed that saccade endpoints on face images were lower when the face was happy and higher when it was neutral. In the second experiment, we explicitly tested the detection of facial expressions. We used a saccadic choice task with emotional-neutral pairs of faces and participants were asked to saccade toward the emotional (happy or fearful) or the neutral face. Participants were faster when they were asked to saccade toward the emotional face. They also made fewer errors, especially when the emotional face was happy. Using computational modeling, we showed that this happy face advantage can, at least partly, be explained by perceptual factors. Also, saccade endpoints were lower when the target was happy than when it was fearful. Overall, we suggest that there is no automatic prioritization of emotional faces, at least for saccades with short latencies, but that salient local face features can automatically attract attention.     

Anxiety meets fear in perception of dynamic expressive gaze

This study investigated in 2 experiments whether reflexive cuing of attention that occurs after perception of a gaze cue is greater for fearful than for happy faces in normal participants, as hypothesized from a social neuroscience perspective. To increase neuroecological validity, dynamic stimulus presentation was used to display faces that simultaneously morphed from a neutral expression into a happy or fearful one and shifted eye gaze from the center to the periphery. Shifts of attention resulting from a natural fearful gaze were expected to be related to participants' anxiety traits, in agreement with the often found increased selective attention to threat in anxious participants. Both hypotheses were confirmed: Fearful faces induced stronger gaze cuing than happy faces, and the strength of this cuing effect was correlated to participants' anxiety levels. These results suggest a neural network, which integrates the processing of gaze, expression, and emotional states to adaptively prime vigilance under threatening circumstances.     

The development of emotional face and eye gaze processing

Recent research has demonstrated that infants' attention towards novel objects is affected by an adult's emotional expression and eye gaze toward the object. The current event-related potential (ERP) study investigated how infants at 3, 6, and 9 months of age process fearful compared to neutral faces looking toward objects or averting gaze away from objects. Furthermore, we examined how the processing of novel objects is affected by gaze direction and emotional expression. We hypothesized that an adult's fearful expression should be particularly salient when it is directed toward a referent in the environment. Furthermore, responses to objects should be increased if the face previously expressed fear toward the object. Three-month-olds did not show differential neural responses to fearful vs. neutral faces regardless of gaze direction. Six-month-olds showed an enhanced negative central (Nc) component for fearful relative to neutral faces looking toward objects, but not when eye gaze was averted away from the objects. Furthermore, 6-month-olds showed an enhanced Nc for objects that had been gaze-cued by a fearful compared to a neutral face. Nine-month-olds showed an enhanced Nc for fearful relative to neutral faces in both eye gaze conditions and showed an enhanced Nc for objects that had been gaze-cued by a neutral face. The findings are discussed in the context of social cognitive and brain development.     

阈下情绪面孔的注视线索提示效应

采用线索-靶子范式，利用2个预实验和1个正式实验，考察阈下不同情绪面孔的注视线索提示效应。要求被试在具有表情与注视线索的面孔呈现完毕后，快速而准确地对目标的位置进行判断。记录被试反应时间。结果显示，当被试未有意识的觉察到注视线索与面孔表情时，注视线索提示效应存在，并受到表情的调节。表现为：在注视线索有效并伴有恐惧表情时，被试对于目标的判断更加迅速；当比较不同表情下线索无效与线索有效条件下的反应时差异时发现，恐惧表情面孔出现时，线索无效与线索有效条件之间反应时的差异最大。结果表明，阈下情绪刺激能够激发个体更原始的生物性反应；在早期注意阶段，个体对于恐惧信息更加敏感，注意存在负向情绪偏差。     

注视方向和面部表情对注意朝向的影响

摘 要 本文以三种表情面孔为材料,运用事件相关电位（ERP）方法探讨表情线索在注意朝向中与注视转移发生的交互及两者如何共同影响观察者的反应。结果发现：（1）线索效应在三种表情面孔的两种SOA中都出现了;（2）SOA较长时,注视线索效应量间的显著差异出现在中性和恐惧面孔、高兴和恐惧面孔间;（3）面部表情的效应出现在了表情线索诱发的P1成分上;（4）目标诱发的P1和N1说明了注视线索效应的存在及与表情间的交互。结论：表情线索先对观察者的朝向反应产生影响,随后是注视线索及其与表情线索发生的交互。     

The world smiles at me: self-referential positivity bias when interpreting direction of attention

Recent research suggests that eye-gaze direction modulates perceived emotional expression. Here we explore the extent to which emotion affects interpretation of attention direction. We captured three-dimensional face models of 8 actors expressing happy, fearful, angry and neutral emotions. From these 3D models 9 views were extracted (0°, 2°, 4°, 6°, 8° to the left and right). These stimuli were randomly presented for 150 ms. Using a forced-choice paradigm 28 participants judged for each face whether or not it was attending to them. Two conditions were tested: either the whole face was visible, or the eyes were covered. In both conditions happy faces elicited most "attending-to-me" answers. Thus, emotional expression has a more general effect than an influence on gaze direction: emotion affects interpretation of attention direction. We interpret these results as a self-referential positivity bias, suggesting a general preference to associate a happy face with the self.     

Increased gaze following for fearful faces. It depends on what you’re looking for!

An oculomotor visual search task was used to investigate how participants follow the gaze of a non-predictive and task irrelevant distractor gaze, and the way in which this gaze following is influenced by the emotional expression (fearful vs. happy) as well as participants' goal. Previous research has suggested that fearful emotions should result in stronger cueing effects than happy faces. Our results demonstrated that the degree to which the emotional expression influenced this gaze following varied as a function of the search target. When searching for a threatening target, participants were more likely to look in the direction of eye gaze on a fearful compared to a happy face. However, when searching for a pleasant target, this stronger cueing effect for fearful faces disappeared. Therefore, gaze following is influenced by contextual factors such as the emotional expression, as well as the participant's goal.     

The interaction between gaze direction and facial expressions in newborns

The ability to decode facial expressions is an important component of social interaction and functioning. This ability is even more fundamental early in life, prior to the development of verbal communication. However, it is still unclear whether newborns can detect, discriminate and process facial expressions, and, if so, what the mechanisms underlying this ability are. In this study, we extend the investigation of perceived emotional expression by manipulating gaze direction with different facial expressions. Specifically, newborns were presented with faces displaying neutral, fearful, or happy facial expressions accompanied with direct or averted gaze, and tested in a visual preference paradigm. Four experiments were conducted in which different combinations of expression and gaze were used. However, only in the fourth experiment did newborns show a visual preference for a specific emotional display; they looked significantly longer at a happy face than a neutral one only when both were accompanied with direct gaze. These results provide support for the advantage of happy facial expressions in the development of a face processing system and suggest that this preference reflects experience acquired during the first few days after birth.     

Anxiety and sensitivity to eye gaze in emotional faces

This paper reports three studies in which stronger orienting to perceived eye gaze direction was revealed when observers viewed faces showing fearful or angry, compared with happy or neutral, emotional expressions. Gaze-related spatial cueing effects to laterally presented fearful faces and centrally presented angry faces were also modulated by the anxiety level of participants, with high- but not low-state anxious individuals revealing enhanced shifts of attention. In contrast, both high- and low-state anxious individuals demonstrated enhanced orienting to averted gaze when viewing laterally presented angry faces. These results provide novel evidence for the rapid integration of facial expression and gaze direction information, and for the regulation of gaze-cued attention by both the emotion conveyed in the perceived face and the degree of anxiety experienced by the observer.     

The world smiles at me: Self-referential positivity bias when interpreting direction of attention

Recent research suggests that eye-gaze direction modulates perceived emotional expression. Here we explore the extent to which emotion affects interpretation of attention direction. We captured three-dimensional face models of 8 actors expressing happy, fearful, angry and neutral emotions. From these 3D models 9 views were extracted (0°, 2°, 4°, 6°, 8° to the left and right). These stimuli were randomly presented for 150 ms. Using a forced-choice paradigm 28 participants judged for each face whether or not it was attending to them. Two conditions were tested: either the whole face was visible, or the eyes were covered. In both conditions happy faces elicited most “attending-to-me” answers. Thus, emotional expression has a more general effect than an influence on gaze direction: emotion affects interpretation of attention direction. We interpret these results as a self-referential positivity bias, suggesting a general preference to associate a happy face with the self.     

Does facial expression affect attention orienting by gaze direction cues?

In 6 experiments, the authors investigated whether attention orienting by gaze direction is modulated by the emotional expression (neutral, happy, angry, or fearful) on the face. The results showed a clear spatial cuing effect by gaze direction but no effect by facial expression. In addition, it was shown that the cuing effect was stronger with schematic faces than with real faces, that gaze cuing could be achieved at very short stimulus onset asynchronies (14 ms), and that there was no evidence for a difference in the strength of cuing triggered by static gaze cues and by cues involving apparent motion of the pupils. In sum, the results suggest that in normal, healthy adults, eye direction processing for attention shifts is independent of facial expression analysis.     

Both fearful and happy expressions interact with gaze direction by 200 ms SOA to speed attention orienting

Attention orienting towards a gazed-at location is fundamental to social attention. Whether gaze cues can interact with emotional expressions other than those signalling environmental threat to modulate this gaze cueing, and whether this integration changes over time, remains unclear. With four experiments we demonstrate that, when perceived motion inherent to dynamic displays is controlled for, gaze cueing is enhanced by both fearful and happy faces compared to neutral faces. This enhancement is seen with stimulus-onset asynchronies ranging from 200–700?ms. Thus, gaze cueing can be reliably modulated by positive expressions, albeit to a smaller degree than fearful ones, and this gaze–emotion integration impacts behaviour as early as 200?ms post-cue onset.     

Emotionally meaningful targets enhance orienting triggered by a fearful gazing face

Studies investigating the effect of emotional expression on spatial orienting to a gazed-at location have produced mixed results. The present study investigated the role of affective context in the integration of emotion processing and gaze-triggered orienting. In three experiments, a face gazed non-predictively to the left or right, and then its expression became fearful or happy. Participants identified (Experiments 1 and 2) or detected (Experiment 3) a peripheral target presented 225 or 525 ms after the gaze cue onset. In Experiments 1 and 3 the targets were either threatening (a snarling dog) or non-threatening (a smiling baby); in Experiment 2 the targets were neutral. With emotionally valenced targets, the gaze-cuing effect was larger when the face was fearful compared to happy—but only with the longer cue–target interval. With neutral targets, there was no interaction between gaze and expression. Our results indicate that a meaningful context optimises attentional integration of gaze and expression information.     

Task-irrelevant direct gaze facilitates visual search for deviant facial expression

The detection of emotional expression is important particularly when the expression is directed towards the viewer. Therefore, we conjectured that the efficiency in visual search for deviant emotional expression is modulated by gaze direction, which is one of the primary clues for encoding the focus of social attention. To examine this hypothesis, two visual search tasks were conducted. In Emotional Face Search, the participants were required to detect an emotional expression amongst distractor faces with neutral expression; in Neutral Face Search they were required to detect a neutral target among emotional distractors. The results revealed that target detection was accelerated when the target face had direct gaze compared to averted gaze for fearful, angry, and neutral targets, but no effect of distractor gaze direction was observed. An additional experiment including multiple display sizes has shown a shallower search slope in search for a target face with direct gaze than that with averted gaze, indicating that the advantage of a target face with direct gaze is attributable to efficient orientation of attention towards target faces. These results indicate that direct gaze facilitates detection of target face in visual scenery even when gaze discrimination is not the primary task at hand.     

The combined effect of gaze direction and facial expression on cueing spatial attention

Empirical evidence shows an effect of gaze direction on cueing spatial attention, regardless of the emotional expression shown by a face, whereas a combined effect of gaze direction and facial expression has been observed on individuals' evaluative judgments. In 2 experiments, the authors investigated whether gaze direction and facial expression affect spatial attention depending upon the presence of an evaluative goal. Disgusted, fearful, happy, or neutral faces gazing left or right were followed by positive or negative target words presented either at the spatial location looked at by the face or at the opposite spatial location. Participants responded to target words based on affective valence (i.e., positive/negative) in Experiment 1 and on letter case (lowercase/uppercase) in Experiment 2. Results showed that participants responded much faster to targets presented at the spatial location looked at by disgusted or fearful faces but only in Experiment 1, when an evaluative task was used. The present findings clearly show that negative facial expressions enhance the attentional shifts due to eye-gaze direction, provided that there was an explicit evaluative goal present.     

面孔参照或观察者参照：性别二态线索、面孔吸引力与表情对正视面孔偏好的影响

本研究探讨了性别二态线索、面孔吸引力和表情对正视面孔偏好的影响。实验1基于面孔参照,被试普遍偏好正视面孔;相对男性化/厌恶和生气/低吸引力的面孔,被试更偏好女性化/高兴和中性/高吸引力的正视面孔;实验2基于观察者参照,总体并未表现出正视偏好;对低吸引力/中性表情/男性化面孔更偏好斜视面孔。     

Anxiety and sensitivity to gaze direction in emotionally expressive faces

This study investigated the role of neutral, happy, fearful, and angry facial expressions in enhancing orienting to the direction of eye gaze. Photographs of faces with either direct or averted gaze were presented. A target letter (T or L) appeared unpredictably to the left or the right of the face, either 300 ms or 700 ms after gaze direction changed. Response times were faster in congruent conditions (i.e., when the eyes gazed toward the target) relative to incongruent conditions (when the eyes gazed away from the target letter). Facial expression did influence reaction times, but these effects were qualified by individual differences in self-reported anxiety. High trait-anxious participants showed an enhanced orienting to the eye gaze of faces with fearful expressions relative to all other expressions. In contrast, when the eyes stared straight ahead, trait anxiety was associated with slower responding when the facial expressions depicted anger. Thus, in anxiety-prone people attention is more likely to be held by an expression of anger, whereas attention is guided more potently by fearful facial expressions.     

Emotionally meaningful targets enhance orienting triggered by a fearful gazing face

Studies investigating the effect of emotional expression on spatial orienting to a gazed-at location have produced mixed results. The present study investigated the role of affective context in the integration of emotion processing and gaze-triggered orienting. In three experiments, a face gazed nonpredictively to the left or right, and then its expression became fearful or happy. Participants identified (Experiments 1 and 2) or detected (Experiment 3) a peripheral target presented 225 or 525 ms after the gaze cue onset. In Experiments 1 and 3 the targets were either threatening (a snarling dog) or nonthreatening (a smiling baby); in Experiment 2 the targets were neutral. With emotionally-valenced targets, the gaze-cuing effect was larger when the face was fearful compared to happy--but only with the longer cue-target interval. With neutral targets, there was no interaction between gaze and expression. Our results indicate that a meaningful context optimizes attentional integration of gaze and expression information.     

Attentional capture by irrelevant emotional distractor faces

We establish attentional capture by emotional distractor faces presented as a "singleton" in a search task in which the emotion is entirely irrelevant. Participants searched for a male (or female) target face among female (or male) faces and indicated whether the target face was tilted to the left or right. The presence (vs. absence) of an irrelevant emotional singleton expression (fearful, angry, or happy) in one of the distractor faces slowed search reaction times compared to the singleton absent or singleton target conditions. Facilitation for emotional singleton targets was found for the happy expression but not for the fearful or angry expressions. These effects were found irrespective of face gender and the failure of a singleton neutral face to capture attention among emotional faces rules out a visual odd-one-out account for the emotional capture. The present study thus establishes irrelevant, emotional, attentional capture.     

Gaze cueing elicited by emotional faces is influenced by affective context

When we observe someone shift their gaze to a peripheral event or object, a corresponding shift in our own attention often follows. This social orienting response, joint attention, has been studied in the laboratory using the gaze cueing paradigm. Here, we investigate the combined influence of the emotional content displayed in two critical components of a joint attention episode: The facial expression of the cue face, and the affective nature of the to-be-localized target object. Hence, we presented participants with happy and disgusted faces as cueing stimuli, and neutral (Experiment 1), pleasant and unpleasant (Experiment 2) pictures as target stimuli. The findings demonstrate an effect of ‘emotional context’ confined to participants viewing pleasant pictures. Specifically, gaze cueing was boosted when the emotion of the gazing face (i.e., happy) matched that of the targets (pleasant). Demonstrating modulation by emotional context highlights the vital flexibility that a successful joint attention system requires in order to assist our navigation of the social world.