Revisiting the relationship between the processing of gaze direction and the processing of facial expression.

There is mixed evidence on the nature of the relationship between the perception of gaze direction and the perception of facial expressions. Major support for shared processing of gaze and expression comes from behavioral studies that showed that observers cannot process expression or gaze and ignore irrelevant variations in the other dimension. However, these studies have not considered the role of head orientation, which is known to play a key role in the processing of gaze direction. In a series of experiments, the relationship between the processing of expression and gaze was tested both with head orientation held constant and with head orientation varied between trials, making it a relevant source of information for computing gaze direction. Results show that when head orientation varied between trials, the processing of facial expression was not interfered with gaze direction, and conversely, the processing of gaze could be made without being interfered from irrelevant variations in expression. These findings suggest that the processing of gaze and the processing of expression are not functionally interconnected as was previously assumed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional expression modulates perceived gaze direction.

Gaze perception is an important social skill, as it portrays information about what another person is attending to. Gaze direction has been shown to affect interpretation of emotional expression. Here the authors investigate whether the emotional facial expression has a reciprocal influence on interpretation of gaze direction. In a forced-choice yes-no task, participants were asked to judge whether three faces expressing different emotions (anger, fear, happiness, and neutral) in different viewing angles were looking at them or not. Happy faces were more likely to be judged as looking at the observer than were angry, fearful, or neutral faces. Angry faces were more often judged as looking at the observer than were fearful and neutral expressions. These findings are discussed on the background of approach and avoidance orientation of emotions and of the self-referential positivity bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A direct link between gaze perception and social attention.

How information is exchanged between the cognitive mechanisms responsible for gaze perception and social attention is unclear. These systems could be independent; the “gaze cueing” effect could emerge from the activation of a general-purpose attentional mechanism that is ignorant of the social nature of the gaze cue. Alternatively, orienting to social gaze direction might be directly determined by the operation of cognitive mechanisms specifically dedicated to gaze perception. This second notion is the dominant assumption in the literature, but there is little direct support for this account. Here, we systematically manipulated observers' perception of gaze direction by implementing a gaze adaptation paradigm. Gaze cueing was reduced only in conditions where perception of specific averted gaze stimuli was impaired (Experiment 1). Adaptation to a pointing stimulus failed to impact gaze cueing (Experiment 2). Overall, these data suggest a direct link between the specific operation of gaze perception mechanisms and the consequential orienting of attention. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Gaze perception requires focused attention: Evidence from an interference task.

The direction of another person's gaze is difficult to ignore when presented at the center of attention. In 6 experiments, perception of unattended gaze was investigated. Participants made directional (left-right) judgments to gazing-face or pointing-hand targets, which were accompanied by a distractor face or hand. Processing of the distractor was assessed via congruency effects on target response times. Congruency effects were found from the direction of distractor hands but not from the direction of distractor gazes (Experiment 1). This pattern persisted even when distractor sizes were increased to compensate for their peripheral presentation (Experiments 2 and 5). In contrast, congruency effects were exerted by profile heads (Experiments 3 and 4). In Experiment 6, isolated eye region distractors produced no congruency effects, even when they were presented near the target. These results suggest that, unlike other facial information, gaze direction cannot be perceived outside the focus of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parallel processing in face perception.

The authors examined face perception models with regard to the functional and temporal organization of facial identity and expression analysis. Participants performed a manual 2-choice go/no-go task to classify faces, where response hand depended on facial familiarity (famous vs. unfamiliar) and response execution depended on facial expression (happy vs. angry). Behavioral and electrophysiological markers of information processing—in particular, the lateralized readiness potential (LRP)—were recorded to assess the time course of facial identity and expression processing. The duration of facial identity and expression processes was manipulated in separate experiments, which allowed testing the differential predictions of alternative face perception models. Together, the reaction time and LRP findings indicate a parallel architecture of facial identity and expression analysis in which the analysis of facial expression relies on information about identity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orienting to Eye Gaze and Face Processing.

The author conducted 7 experiments to examine possible interactions between orienting to eye gaze and specific forms of face processing. Participants classified a letter following either an upright or inverted face with averted, uninformative eye gaze. Eye gaze orienting effects were recorded for upright and inverted faces, irrespective of whether the faces were simple, schematic faces or more realistic faces. In contrast, inversion affected orienting to targets appearing along the vertical axis. Switching the contrast between the iris and sclera reversed orienting to eye gaze. Lifting the eyelid to expose more of the iris-sclera contrast led to a potentiation of orienting to eye gaze. Raising the eyebrow alone without the eyelid did not affect orienting. The findings suggest that local perceptual information is critical for orienting to eye gaze and that the effect can occur with a degree of independence from certain types of face processing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric perception of emotional valence from facial expressions.

The authors previously reported that normal subjects are better at discriminating happy from neutral faces when the happy face is located to the viewer's right of the neutral face; conversely, discrimination of sad from neutral faces is better when the sad face is shown to the left, supporting a role for the left hemisphere in processing positive valence and for the right hemisphere in processing negative valence. Here, the authors extend this same task to subjects with unilateral cerebral damage (31 right, 28 left). Subjects with right damage performed worse when discriminating sad faces shown on the left, consistent with the prior findings. However, subjects with either left or right damage actually performed superior to normal controls when discriminating happy faces shown on the left. The authors suggest that perception of negative valence relies preferentially on the right hemisphere, whereas perception of positive valence relies on both left and right hemispheres. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The processing of invariant and variant face cues in the Garner Paradigm.

Faces provide a complex source of information via invariant (e.g., race, sex and age) and variant (e.g., emotional expressions) cues. At present, it is not clear whether these different cues are processed separately or whether they interact. Using the Garner Paradigm, Experiment 1 confirmed that race, sex, and age cues affected the categorization of faces according to emotional expression whereas emotional expression had no effect on the categorization of faces by sex, age, or race. Experiment 2 used inverted faces and replicated this pattern of asymmetrical interference for race and age cues, but not for sex cues for which no interference on emotional expression categorization was observed. Experiment 3 confirmed this finding with a more stringently matched set of facial stimuli. Overall, this study shows that invariant cues interfere with the processing of emotional expressions. It indicates that the processing of invariant cues, but not of emotional expressions, is obligatory and that it precedes that of emotional expressions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Attention to gaze and emotion in schizophrenia.

Objective: Individuals with schizophrenia have difficulty interpreting social and emotional cues such as facial expression, gaze direction, body position, and voice intonation. Nonverbal cues are powerful social signals but are often processed implicitly, outside the focus of attention. The aim of this research was to assess implicit processing of social cues in individuals with schizophrenia. Method: Patients with schizophrenia or schizoaffective disorder and matched controls performed a primary task of word classification with social cues in the background. Participants were asked to classify target words (LEFT/RIGHT) by pressing a key that corresponded to the word, in the context of facial expressions with eye gaze averted to the left or right. Results: Although facial expression and gaze direction were irrelevant to the task, these facial cues influenced word classification performance. Participants were slower to classify target words (e.g., LEFT) that were incongruent to gaze direction (e.g., eyes averted to the right) compared to target words (e.g., LEFT) that were congruent to gaze direction (e.g., eyes averted to the left), but this only occurred for expressions of fear. This pattern did not differ for patients and controls. Conclusion: The results showed that threat-related signals capture the attention of individuals with schizophrenia. These data suggest that implicit processing of eye gaze and fearful expressions is intact in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-relevance processing in the human amygdala: Gaze direction, facial expression, and emotion intensity.

How the processing of emotional expression is influenced by perceived gaze remains a debated issue. Discrepancies between previous results may stem from differences in the nature of stimuli and task characteristics. Here we used a highly controlled set of computer-generated animated faces combining dynamic emotional expressions with varying intensity, and gaze shifts either directed at or averted from the observer. We predicted that perceived self-relevance of fearful faces would be higher with averted gaze—signaling a nearby danger; whereas conversely, direct gaze would be more relevant for angry faces—signaling aggressiveness. This interaction pattern was observed behaviorally for emotion intensity ratings, and neurally for functional magnetic resonance imaging activation in amygdala, as well as fusiform and medial prefrontal cortices, but only for mild- and not high-intensity expressions. These results support an involvement of human amygdala in the appraisal of self-relevance and reveal a crucial role of expression intensity in emotion and gaze interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple mechanisms in the perception of face gender: Effect of sex-irrelevant features.

Effects of sex-relevant and sex-irrelevant facial features on the evaluation of facial gender were investigated. Participants rated masculinity of 48 male facial photographs and femininity of 48 female facial photographs. Eighty feature points were measured on each of the facial photographs. Using a generalized Procrustes analysis, facial shapes were converted into multidimensional vectors, with the average face as a starting point. Each vector was decomposed into a sex-relevant subvector and a sex-irrelevant subvector which were, respectively, parallel and orthogonal to the main male–female axis. Principal components analysis (PCA) was performed on the sex-irrelevant subvectors. One principal component was negatively correlated with both perceived masculinity and femininity, and another was correlated only with femininity, though both components were orthogonal to the male–female dimension (and thus by definition sex-irrelevant). These results indicate that evaluation of facial gender depends on sex-irrelevant as well as sex-relevant facial features. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging and goal-directed emotional attention: Distraction reverses emotional biases.

Previous findings reveal that older adults favor positive over negative stimuli in both memory and attention (for a review, see Mather & Carstensen, 2005). This study used eye tracking to investigate the role of cognitive control in older adults' selective visual attention. Younger and older adults viewed emotional-neutral and emotional-emotional pairs of faces and pictures while their gaze patterns were recorded under full or divided attention conditions. Replicating previous eye-tracking findings, older adults allocated less of their visual attention to negative stimuli in negative-neutral stimulus pairings in the full attention condition than younger adults did. However, as predicted by a cognitive-control-based account of the positivity effect in older adults' information processing tendencies (Mather & Knight, 2005), older adults' tendency to avoid negative stimuli was reversed in the divided attention condition. Compared with younger adults, older adults' limited attentional resources were more likely to be drawn to negative stimuli when they were distracted. These findings indicate that emotional goals can have unintended consequences when cognitive control mechanisms are not fully available. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of directed gaze in rhesus monkeys (Macaca mulatta).

To examine the ability of monkeys to detect the direction of attention of other individuals, the authors quantitatively investigated the visual scanning pattern of rhesus monkeys (Macaca mulatta) in response to visually presented images of a human frontal face. The present results demonstrated not only that monkeys predominantly gaze at the eyes as compared with other facial areas in terms of duration and number of fixations, but also that they gaze at the eyes for a longer time period and more frequently when a human face, presented as a stimulus, gazed at them than when the gaze was shifted. These results indicate that rhesus monkeys are sensitive to the directed gaze of humans, suggesting that monkeys pay more attention to the human whose attention is directed to them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gaze direction modulates the disengagement of attention from facial expression in 10-month-olds.

This study investigated whether the disengagement of attention from facial expression is modulated by gaze direction in infants. To this end, we measured the saccadic reaction time required for the 10-month-olds to disengage their attention from angry and happy expressions combined with either straight or averted gaze. The 10-month-olds' disengagement of their attention from happy faces was modulated by gaze direction. This finding indicates that gaze direction strongly influences infants' allocation of attention to facial expressions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related declines in basic social perception: Evidence from tasks assessing eye-gaze processing.

Previous research has investigated age differences in complex social perception tasks such as theory of mind and emotion recognition, with predominant findings of age-related declines. The present study investigated whether there are also age-related changes in basic aspects of social perception. Individuals' ability both to detect subtle differences in eye-gaze direction (e.g., where someone is looking in the environment) and to subsequently use these gaze cues to engage in joint attention with others was assessed. Age-related declines were found in the detection of the most subtle differences in gaze aversion. The ability to engage in joint attention by following gaze cues also declined with age. These age differences were not solely attributable to age impairments in visual perception and visual attention. The potential role of age-related neural declines in social perception problems was considered, along with the implications that age deficits in these basic social skills may have for older adults' social perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orienting and maintenance of gaze to facial expressions in social anxiety.

In 2 experiments, the authors tested predictions from cognitive models of social anxiety regarding attentional biases for social and nonsocial cues by monitoring eye movements to pictures of faces and objects in high social anxiety (HSA) and low social anxiety (LSA) individuals. Under no-stress conditions (Experiment 1), HSA individuals initially directed their gaze toward neutral faces, relative to objects, more often than did LSA participants. However, under social-evaluative stress (Experiment 2), HSA individuals showed reduced biases in initial orienting and maintenance of gaze on faces (cf. objects) compared with the LSA group. HSA individuals were also relatively quicker to look at emotional faces than neutral faces but looked at emotional faces for less time, compared with LSA individuals, consistent with a vigilant-avoidant pattern of bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive correlates of emotional traits: Perceptions of self and others.

Two studies examined how individuals' perceptions of self and others are associated with different emotional traits. Study 1 (N = 386) used structural equation modeling of questionnaire data to examine the relations between emotional traits (i.e., affect intensity, affect variability, and trait pleasant and unpleasant affect) and self- and other-perceptions (i.e., self-instability, self-esteem, other-instability, and perceived treatment by others). Study 2 (N = 99) used path analyses of data collected using an event sampling method in which online measures of emotional experiences (i.e., intensity, frequency, and variability of pleasant and unpleasant affect) as well as perceptions of self and others (i.e., self-instability, self-esteem, other-instability, perceived treatment by others) were collected. The strongest and most consistent finding was that affect variability was associated with both self- and other-instability. The results linking affect intensity with self- and other-instability were limited to negative intensity. There was also evidence of pleasant affect being associated with both self-esteem and perceived treatment by others, and unpleasant affect being associated with self-esteem and other-instability. (PsycINFO Database Record (c) 2011 APA, all rights reserved)