More efficient rejection of happy than of angry face distractors in visual search

In the present study, we examined whether the detection advantage for negative-face targets in crowds of positive-face distractors over positive-face targets in crowds of negative faces can be explained by differentially efficient distractor rejection. Search Condition A demonstrated more efficient distractor rejection with negative-face targets in positive-face crowds than vice versa. Search Condition B showed that target identity alone is not sufficient to account for this effect, because there was no difference in processing efficiency for positive- and negative-face targets within neutral crowds. Search Condition C showed differentially efficient processing with neutral-face targets among positive- or negative-face distractors. These results were obtained with both a within-participants (Experiment 1) and a between-participants (Experiment 2) design. The pattern of results is consistent with the assumption that efficient rejection of positive (more homogenous) distractors is an important determinant of performance in search among (face) distractors.     

Modeling automatic threat detection: development of a face-in-the-crowd task

An angry face is expected to be detected faster than a happy face because of an early, stimulus-driven analysis of threat-related properties. However, it is unclear to what extent results from the visual search approach-the face-in-the-crowd task-mirror this automatic analysis. The paper outlines a model of automatic threat detection that combines the assumption of a neuronal system for threat detection with contemporary theories of visual search. The model served as a guideline for the development of a new face-in-the-crowd task. The development involved three preliminary studies that provided a basis for the selection of angry and happy facial stimuli resembling each other in respect to perceptibility, homogeneity, and intensity. With these stimuli a signal detection version of the search task was designed and tested. For crowds composed of neutral faces, the sensitivity measure d' proved the expected detection advantage of angry faces compared to happy faces. However, the emotional expression made no difference if a neutral face had to be detected in crowd composed of either angry or happy faces. Results are in line with the assumption of a stimulus-driven shift of attention giving rise to the superior detection of angry target faces.     

Attentional effects of negative faces: Top-down contingent or involuntary?

Recent research has substantiated that schematic negative faces are found more efficiently than positive faces among crowds of distractor faces of varying set sizes. The present study asks whether this relative search asymmetry (RSA) is intention driven or due to involuntary attentional capture. To that aim, participants were first tested in a condition in which negative and positive faces were searched for, and then in a condition in which negative or positive schematic faces appeared at chance level at the position of the target (valid trials) or of a distractor (invalid trials), the faces thus being task irrelevant (the 1/n paradigm). The expected search benefit for valid negative-face target trials most clearly occurred when participants searched for a target defined by a conjunction of color and position; when the target was defined either by an orientation or color singleton, we found rather weak or no evidence for involuntary attention capture by negative faces. We see the results as being (1) evidence that the RSA is partly based on stimulus-driven factors that occur independently of the intention to search for a positive or negative face, and (2) consistent with the assumption that the effects are mainly due to a more efficient rejection of positive-face than of negative-face distractors, rather than being due to attentional capture by the target     

Repression at encoding: discrete appraisals of emotional stimuli.

In previous research, the emotions associated with repressors' memorial representations were found to be more discrete than those associated with nonrepressors'. In each of the 3 experiments reported here, repressive discreteness was apparent in repressors' appraisals of emotional stimuli at the time they were encoded. In 1 experiment, Ss appraised individual facial expressions of emotion. Repressors judged the dominant emotions in these faces as no less intense than did nonrepressors, but they appraised the blend of nondominant emotions as less intense than did nonrepressors. In the remaining 2 experiments, Ss appraised crowds of emotional faces as well as crowds of geometric shapes. In both crowd experiments, the repressive discreteness was evident in appraisals of crowds of emotional faces but not in appraisals of crowds of geometric shapes. The repressive discreteness effect did not appear to reflect a general repressor-nonrepressor difference in the appraisal of stimulus features. Rather, the results suggested that repressive discreteness may be constrained to appraisals of emotions.     

The face in the crowd effect unconfounded: happy faces, not angry faces, are more efficiently detected in single- and multiple-target visual search tasks

Is it easier to detect angry or happy facial expressions in crowds of faces? The present studies used several variations of the visual search task to assess whether people selectively attend to expressive faces. Contrary to widely cited studies (e.g., ?hman, Lundqvist, & Esteves, 2001) that suggest angry faces "pop out" of crowds, our review of the literature found inconsistent evidence for the effect and suggested that low-level visual confounds could not be ruled out as the driving force behind the anger superiority effect. We then conducted 7 experiments, carefully designed to eliminate many of the confounding variables present in past demonstrations. These experiments showed no evidence that angry faces popped out of crowds or even that they were efficiently detected. These experiments instead revealed a search asymmetry favoring happy faces. Moreover, in contrast to most previous studies, the happiness superiority effect was shown to be robust even when obvious perceptual confounds--like the contrast of white exposed teeth that are typically displayed in smiling faces--were eliminated in the happy targets. Rather than attribute this effect to the existence of innate happiness detectors, we speculate that the human expression of happiness has evolved to be more visually discriminable because its communicative intent is less ambiguous than other facial expressions.     

Social anxiety and evaluation of social crowds: explicit and implicit measures

To investigate whether social anxiety disorder is indeed characterized by a biased negative evaluation of facial expressions, 25 highly socially anxious (SA) participants and 30 non-anxious controls (NACs) were asked to respond to different ratios of neutral-angry or happy-angry face combinations (crowds). In an indirect Approach-Avoidance Task (AAT), participants used a joystick to pull the crowds towards themselves (approach) or push them away (avoidance). SAs showed faster avoidance of neutral-angry crowds when the number of angry faces in the crowd increased. The happy-angry crowds were generally avoided, independent of the ratio of the two emotions. NACs did not show any specific response tendency. When directly rating the friendliness of the crowds, the two groups did not differ.     

Neural mechanisms of the automatic processing of emotional information from faces and voices

Theoretical accounts suggest an increased and automatic neural processing of emotional, especially threat-related, facial expressions and emotional prosody. In line with this assumption, several functional imaging studies showed activation to threat-related faces and voices in subcortical and cortical brain areas during attentional distraction or unconscious stimulus processing. Furthermore, electrophysiological studies provided evidence for automatic early brain responses to emotional facial expressions and emotional prosody. However, there is increasing evidence that available cognitive resources modulate brain responses to emotional signals from faces and voices, even though conflicting findings may occur depending on contextual factors, specific emotions, sensory modality, and neuroscientific methods used. The current review summarizes these findings and suggests that further studies should combine information from different sensory modalities and neuroscientific methods such as functional neuroimaging and electrophysiology. Furthermore, it is concluded that the variable saliency and relevance of emotional social signals on the one hand and available cognitive resources on the other hand interact in a dynamic manner, making absolute boundaries of the automatic processing of emotional information from faces and voices unlikely.     

Attentional biases using the body in the crowd task: Are angry body postures detected more rapidly?

Research using schematic faces has consistently demonstrated attentional biases towards threatening information (angry faces), which are accentuated for individuals with higher levels of anxiety. However, research has yet to reveal whether this is the case for other nonverbal channels of communication. In the research reported here, ninety-five undergraduates completed a body in the crowd task analogous to the face in the crowd task, to examine whether attentional biases for threat existed for schematic body postures. Participants demonstrated faster detection of threat. A discrepant angry posture in a neutral crowd was identified quicker than a discrepant happy posture in a neutral crowd. This effect was pronounced for individuals with higher self-reported levels of trait anxiety. Results also demonstrated evidence of delayed disengagement from threat. Individuals were slower (i.e., more distracted) by identical crowds of angry postures rather than happy or neutral crowds and were slower to detect a discrepant neutral posture among an angry crowd than neutral among a happy crowd. These findings are the first to establish threat biases using body postures in a visual search paradigm. The results are in accordance with previous research using schematic face stimuli. Theoretical and practical implications are discussed.     

Attentional biases using the body in the crowd task: are angry body postures detected more rapidly?

Research using schematic faces has consistently demonstrated attentional biases towards threatening information (angry faces), which are accentuated for individuals with higher levels of anxiety. However, research has yet to reveal whether this is the case for other nonverbal channels of communication. In the research reported here, ninety-five undergraduates completed a body in the crowd task analogous to the face in the crowd task, to examine whether attentional biases for threat existed for schematic body postures. Participants demonstrated faster detection of threat. A discrepant angry posture in a neutral crowd was identified quicker than a discrepant happy posture in a neutral crowd. This effect was pronounced for individuals with higher self-reported levels of trait anxiety. Results also demonstrated evidence of delayed disengagement from threat. Individuals were slower (i.e., more distracted) by identical crowds of angry postures rather than happy or neutral crowds and were slower to detect a discrepant neutral posture among an angry crowd than neutral among a happy crowd. These findings are the first to establish threat biases using body postures in a visual search paradigm. The results are in accordance with previous research using schematic face stimuli. Theoretical and practical implications are discussed.     

The face in the crowd effect: Threat-detection advantage with perceptually intermediate distractors

The ability to quickly perceive threatening facial expressions allows one to detect emotional states and respond appropriately. The anger superiority hypothesis predicts that angry faces capture attention faster than happy faces. Previous studies have used photographic (Hansen & Hansen, 1988) and schematic face images (e.g., Eastwood, Smilek, & Merikle, 2001; Ohman, Lunqvist, & Esteves, 2001) in studying the anger superiority effect, but specific confounds due to the construction of stimuli have led to conflicting findings. In the current study, participants performed a visual search for either angry or happy target faces among crowds of novel, perceptually intermediate morph distractors. A threat-detection advantage was evident where participants showed faster reaction times and greater accuracy in detecting angry over happy faces. Search slopes, however, did not significantly differ. Results suggest a threat-detection advantage mediated by serial rather than preattentive processing.     

Social anxiety biases the evaluation of facial displays: evidence from single face and multi-facial stimuli

This study examined the contribution of social anxiety to the evaluation of emotional facial stimuli, while controlling for the gender of participants and stimuli. Participants (n=63) completed two tasks: a single face evaluation task in which they had to evaluate angry versus neutral faces and, a facial crowd evaluation task in which they had to evaluate displays with a varying number of neutral and angry faces. In each task, participants had to evaluate the stimuli with respect to (a) the degree of disapproval expressed by the single face/crowd, and (b) the perceived difficulty of interacting with the face/crowd (emotional cost). Consistent with earlier studies, results showed that social anxiety modulated the evaluation of single faces for emotional cost, but not for disapproval ratings. In contrast, the evaluation of facial crowds was modulated by social anxiety on both ratings.     

I’d know that face anywhere!

Mandler (1980) provided the classic “butcher on the bus” example illustrating the feeling of familiarity without recollection that may arise when an acquaintance is encountered in an unusual context. We studied this phenomenon by pairing photos of faces with photos of distinctive contexts at study and later testing recognition memory andremember/know judgments for faces presented with studied, switched, or new contexts. Estimates of recollection and familiarity, based on the assumption that these processes are independent, showed that switching contexts significantly lowered recollection while leaving familiarity intact, just as Mandler described. False alarm rates were higher with old contexts, suggesting that subjects tended to misattribute memories of contexts to memories of faces. These results provide the first evidence of context effects on the subjective experience of recognizing faces. One-dimensional signal-detection models fit the data, but such models do not explain the difference in remember responses between studied and switched items, whereas dual-process models (which also fit the data) do while also capturing the phenomenology of the butcher-on-the-bus experience in an intuitively appealing way.     

Social anxiety biases the evaluation of facial displays: Evidence from single face and multi-facial stimuli

This study examined the contribution of social anxiety to the evaluation of emotional facial stimuli, while controlling for the gender of participants and stimuli. Participants (n=63) completed two tasks: a single face evaluation task in which they had to evaluate angry versus neutral faces and, a facial crowd evaluation task in which they had to evaluate displays with a varying number of neutral and angry faces. In each task, participants had to evaluate the stimuli with respect to (a) the degree of disapproval expressed by the single face/crowd, and (b) the perceived difficulty of interacting with the face/crowd (emotional cost). Consistent with earlier studies, results showed that social anxiety modulated the evaluation of single faces for emotional cost, but not for disapproval ratings. In contrast, the evaluation of facial crowds was modulated by social anxiety on both ratings.     

The relationship between visual search and categorization of own- and other-age faces

Young adult participants are faster to detect young adult faces in crowds of infant and child faces than vice versa. These findings have been interpreted as evidence for more efficient attentional capture by own-age than other-age faces, but could alternatively reflect faster rejection of other-age than own-age distractors, consistent with the previously reported other-age categorization advantage: faster categorization of other-age than own-age faces. Participants searched for own-age faces in other-age backgrounds or vice versa. Extending the finding to different other-age groups, young adult participants were faster to detect young adult faces in both early adolescent (Experiment 1) and older adult backgrounds (Experiment 2). To investigate whether the own-age detection advantage could be explained by faster categorization and rejection of other-age background faces, participants in experiments 3 and 4 also completed an age categorization task. Relatively faster categorization of other-age faces was related to relatively faster search through other-age backgrounds on target absent trials but not target present trials. These results confirm that other-age faces are more quickly categorized and searched through and that categorization and search processes are related; however, this correlational approach could not confirm or reject the contribution of background face processing to the own-age detection advantage.     

Selective attention to imagined facial ugliness is specific to body dysmorphic disorder

Cognitive-behavioral models postulate that biases in selective attention are key factors contributing to susceptibility to and maintenance of body dysmorphic disorder (BDD). Visual attention in particular toward the imagined defect in appearance may be a crucial element. The present study therefore examined whether individuals with BDD showed increased visual attention to flaws in their own and in unfamiliar faces. Twenty individuals with BDD, 20 individuals with social phobia, and 20 mentally healthy individuals participated in an eye-tracking experiment. Participants were instructed to gaze at the photographs of 15 pictures of themselves and several unfamiliar faces. Only patients with BDD showed heightened selective visual attention to the imagined defect in their own face, as well to corresponding regions in other, unfamiliar faces. The results support the assumption that there is a specific attentional bias in BDD.     

Divided attention, order of report and responses to immediately successive signals

Two effects, “divided-attention” and “order of report”, are operationally denned. Their relative contributions to the reduction in efficiency which accompanies the recognition of difficult nonverbal signals, presented simultaneously, is considered. Experiment I evaluated the two effects in the absence of a fixed order of report and emphasis instructions, confounding features of previous studies. The results showed: an overall impairment of performance with simultaneous signals; a contribution of both effects to the decrement, with a suggestion of the primacy of the “order of report” effect; and a significant interaction between the latter effect and modality, such that visual signals showed the greater effect. Experiment II using similar signals tested the assumption that simultaneity of presentation is a necessary condition for obtaining reduced efficiency with multiple signals. The assumption was only partially confirmed, a significant decrement in performance occurring only for the second of two successively presented signals. Similarities between the two sets of results are noted, as well as between these and modality differences obtained with verbal materials. Two possible accounts of the data are proposed, one based on “input”, the other on “storage” models of divided-attention. The hypothesis that subjects report the most clearly perceived signal first is rejected as an independent explanation.     

面孔部件在群体注意方向判断中的作用

探讨面孔部件(眼睛和鼻子)在个体和群体注意方向判断中的作用。实验1使用不同数量面孔的图片,要求报告群体或个体的注意方向。结果发现,多面孔条件下对群体注意方向估计的准确性高于单面孔条件。实验2采用眼动技术,探讨眼睛和鼻子在判断其注意方向时注视的空间与时间分布特征。结果发现,基于单张面孔判断时,对鼻子的总注视时间长于眼睛;基于多张面孔判断时,对眼睛和鼻子的总注视时间没有差异。整个研究表明,知觉个体注意主要依赖鼻子,知觉群体注意依赖眼睛和鼻子。     

Computational perspectives on the other-race effect

Psychological studies have long shown that human memory is superior for faces of our own-race than for faces of other-races. In this paper, we review computational studies of own- versus other-race face processing. Computational models examine the visual challenges of representing the uniqueness of individual faces that vary both within and across demographic categories. These models isolate the visual components of the other-race effect and provide an objective control for socioaffective responses to other-race faces. This control allows researchers to compare and test the role of experience/contact in the other-race effect, using various operational definitions of this theoretical construct. The models show that to produce an other-race effect computationally, biased experience or learning must intervene during the process of feature selection. This implicates the critical importance of “developmental” learning in the other-race effect.     

A unified account of the effects of distinctiveness, inversion, and race in face recognition

A framework is outlined in which individual faces are assumed to be encoded as a point in a multidimensional space, defined by dimensions that serve to discriminate faces. It is proposed that such a framework can account for the effects of distinctiveness, inversion, and race on recognition of faces. Two specific models within this framework are identified: a norm-based coding model, in which faces are encoded as vectors from a population norm or prototype; and a purely exemplar-based model. Both models make similar predictions, albeit in different ways, concerning the interactions between the effects of distinctiveness, inversion and race. These predictions were supported in five experiments in which photographs of faces served as stimuli. The norm-based coding version and the exemplar-based version of the framework cannot be distinguished on the basis of the experiments reported, but it is argued that a multidimensional space provides a useful heuristic framework to investigate recognition of faces. Finally, the relationship between the specific models is considered and an implementation in terms of parallel distributed processing is briefly discussed.     

Threatening joy: Approach and avoidance reactions to emotions are influenced by the group membership of the expresser

It has been repeatedly stated that approach and avoidance reactions to emotional faces are triggered by the intention signalled by the emotion. This line of thought suggests that each emotion signals a specific intention triggering a specific behavioural reaction. However, empirical results examining this assumption are inconsistent, suggesting that it might be too short-sighted. We hypothesise that the same emotional expression can signal different social messages and, therefore, trigger different reactions; which social message is signalled by an emotional expression should be influenced by moderating variables, such as the group membership of the expresser. In two experiments, we show that group membership influences approach and avoidance reactions to emotional expressions: Emotions (fear and happiness) expressed by in-group members elicited concordant behaviour, whereas emotions expressed by out-group members activated the reverse pattern. A third experiment, in which participants directly evaluated smiling and fearful individuals resembling in-group and out-group members supported this result.