Garner interference reveals dependencies between emotional expression and gaze in face perception

The relationship between facial expression and gaze processing was investigated with the Garner selective attention paradigm. In Experiment 1, participants performed expression judgments without interference from gaze, but expression interfered with gaze judgments. Experiment 2 replicated these results across different emotions. In both experiments, expression judgments occurred faster than gaze judgments, suggesting that expression was processed before gaze could interfere. In Experiments 3 and 4, the difficulty of the emotion discrimination was increased in two different ways. In both cases, gaze interfered with emotion judgments and vice versa. Furthermore, increasing the difficulty of the emotion discrimination resulted in gaze and expression interactions. Results indicate that expression and gaze interactions are modulated by discriminability. Whereas expression generally interferes with gaze judgments, gaze direction modulates expression processing only when facial emotion is difficult to discriminate.     

Speaker variations influence speechreading speed for dynamic faces

We investigated the influence of task-irrelevant speaker variations on speechreading performance. In three experiments with video digitised faces presented either in dynamic, static-sequential, or static mode, participants performed speeded classifications on vowel utterances (German vowels /u/ and /i/). A Garner interference paradigm was used, in which speaker identity was task-irrelevant but could be either correlated, constant, or orthogonal to the vowel uttered. Reaction times for facial speech classifications were slowed by task-irrelevant speaker variations for dynamic stimuli. The results are discussed with reference to distributed models of face perception (Haxby et al, 2000 Trends in Cognitive Sciences 4 223-233) and the relevance of both dynamic information and speaker characteristics for speechreading.     

Selective attention to facial identity and emotion in children

Three age groups of participants (6–8 years, 9–11 years, adults) performed two tasks: A face recognition task and a Garner task. In the face recognition task, the participants were presented with 20 faces and then had to recognize them among 20 new faces. In the Garner tasks, the participants had to sort, as fast as possible, the photographs of two persons expressing two emotions by taking into account only one of the two dimensions (identity or emotion). When the sorting task was on one dimension, the other dimension was varied either in a correlated, a constant or an orthogonal way in distinct subsessions. The results indicated an increase in face recognition abilities. They also showed an interference of identity in the emotion-sorting task that was similar in the three age groups. Nevertheless, an interference of emotion in the identity-sorting task was significant only for the children and was more important for the youngest group. These observations suggest that the development in face recognition ability rests on the development of the ability to attend selectively to identity, without paying attention to emotional facial expression.     

Asymmetric dependencies in perceiving identity and emotion: experiments with morphed faces.

We investigated whether an asymmetric relationship between the perception of identity and emotional expressions in faces (Schweinberger & Soukup, 1998) may be related to differences in the relative processing speed of identity and expression information. Stimulus faces were morphed across identity within a given emotional expression, or were morphed across emotion within a given identity. In Experiment 1, consistent classifications of these images were demonstrated across a wide range of morphing, with only a relatively narrow category boundary. At the same time, classification reaction times (RTs) reflected the increased perceptual difficulty of the morphed images. In Experiment 2, we investigated the effects of variations in the irrelevant dimension on judgments of faces with respect to a relevant dimension, using a Garner-type speeded classification task. RTs for expression classifications were strongly influenced by irrelevant identity information. In contrast, RTs for identity classifications were unaffected by irrelevant expression information, and this held even for stimuli in which identity was more difficult and slower to discriminate than expression. This suggests that differences in processing speed cannot account for the asymmetric relationship between identity and emotion perception. Theoretical accounts proposing independence of identity and emotion perception are discussed in the light of these findings.     

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.     

Flexible and inflexible task sets: asymmetric interference when switching between emotional expression, sex, and age classification of perceived faces

The present study investigated whether the processing characteristics of categorizing emotional facial expressions are different from those of categorizing facial age and sex information. Given that emotions change rapidly, it was hypothesized that processing facial expressions involves a more flexible task set that causes less between-task interference than the task sets involved in processing age or sex of a face. Participants switched between three tasks: categorizing a face as looking happy or angry (emotion task), young or old (age task), and male or female (sex task). Interference between tasks was measured by global interference and response interference. Both measures revealed patterns of asymmetric interference. Global between-task interference was reduced when a task was mixed with the emotion task. Response interference, as measured by congruency effects, was larger for the emotion task than for the nonemotional tasks. The results support the idea that processing emotional facial expression constitutes a more flexible task set that causes less interference (i.e., task-set "inertia") than processing the age or sex of a face.     

Flexible and inflexible task sets: Asymmetric interference when switching between emotional expression,sex, and age classification of perceived faces

The present study investigated whether the processing characteristics of categorizing emotional facial expressions are different from those of categorizing facial age and sex information. Given that emotions change rapidly, it was hypothesized that processing facial expressions involves a more flexible task set that causes less between-task interference than the task sets involved in processing age or sex of a face. Participants switched between three tasks: categorizing a face as looking happy or angry (emotion task), young or old (age task), and male or female (sex task). Interference between tasks was measured by global interference and response interference. Both measures revealed patterns of asymmetric interference. Global between-task interference was reduced when a task was mixed with the emotion task. Response interference, as measured by congruency effects, was larger for the emotion task than for the nonemotional tasks. The results support the idea that processing emotional facial expression constitutes a more flexible task set that causes less interference (i.e., task-set “inertia”) than processing the age or sex of a face     

Interactions between facial emotion and identity in face processing: Evidence based on redundancy gains

Interactions between the processing of emotion expression and form-based information from faces (facial identity) were investigated using the redundant-target paradigm, in which we specifically tested whether identity and emotional expression are integrated in a superadditive manner (Miller, Cognitive Psychology 14:247?C279, 1982). In Experiments 1 and 2, participants performed emotion and face identity judgments on faces with sad or angry emotional expressions. Responses to redundant targets were faster than responses to either single target when a universal emotion was conveyed, and performance violated the predictions from a model assuming independent processing of emotion and face identity. Experiment 4 showed that these effects were not modulated by varying interstimulus and nontarget contingencies, and Experiment 5 demonstrated that the redundancy gains were eliminated when faces were inverted. Taken together, these results suggest that the identification of emotion and facial identity interact in face processing.     

Asymmetric dependencies in perceiving identity and emotion: Experiments with morphed faces

We investigated whether an asymmetric relationship between the perception of identity and emo-tional expressions in faces (Schweinberger & Soukup, 1998) may be related to differences in the rela-tive processing speed of identity and expression information. Stimulus faces were morphed across identity within a given emotional expression, or were morphed across emotion within a given identity. In Experiment 1, consistent classifications of these images were demonstrated across a wide range of morphing, with only a relatively narrow category boundary. At the same time, classification reaction times (RTs) reflected the increased perceptual difficulty of the morphed images. In Experiment 2, we investigated the effects of variations in the irrelevant dimension on judgments of faces with respect to a relevant dimension, using a Garner-type speeded classification task. RTs for expression classifica-tions were strongly influenced by irrelevant identity information. In contrast, RTs for identity classifi-cations were unaffected by irrelevant expression information, and this held even for stimuli in which identity was more difficult and slower to discriminate than expression. This suggests that differences in processing speed cannot account for the asymmetric relationship between identity and emotion per-ception. Theoretical accounts proposing independence of identity and emotion perception are dis-cussed in the light of these findings.     

Facial identity and facial expression matching in 5–12‐year‐old children and adults

Facial identity and facial expression matching tasks were completed by 5–12‐year‐old children and adults using stimuli extracted from the same set of normalized faces. Configural and feature processing were examined using speed and accuracy of responding and facial feature selection, respectively. Facial identity matching was slower than face expression matching for all age groups. Large age effects were found on both speed and accuracy of responding and feature use in both identity and expression matching tasks. Eye region preference was found on the facial identity task and mouth region preference on the facial expression task. Use of mouth region information for facial expression matching increased with age, whereas use of eye region information for facial identity matching peaked early. The feature use information suggests that the specific use of primary facial features to arrive at identity and emotion matching judgments matures across middle childhood. Copyright © 2009 John Wiley & Sons, Ltd.     

面孔熟悉度对面孔性别与表情相互作用的调节

对于面孔性别与表情的关系, 目前的理论尚不完善。而众多研究证据表明, 面孔熟悉度与面孔性别及表情的加工均有密切关系。本研究基于Garner范式考察了在不同面孔熟悉度下面孔性别与表情的相互关系。共包括4项实验：实验1, 面孔刺激的身份陌生且不重复, 刺激在Garner范式的控制组和正交组中均仅呈现一次, 面孔熟悉度低; 实验2, 除面孔刺激的身份重复外, 其余均同实验1, 面孔熟悉度中等; 实验3, 面孔刺激的身份陌生且不重复, 但分别在控制组和正交组中重复呈现多次, 面孔熟悉度高; 实验4, 通过面孔学习增加面孔的熟悉度, 以直接验证面孔熟悉度的增加对面孔性别与表情相互关系的影响。结果发现：对于陌生面孔, 表情单向影响面孔性别的加工; 随着面孔熟悉度的增加, 面孔性别与表情之间出现双向的影响。因此, 面孔熟悉度对面孔性别与表情的相互影响具有调节作用。     

Sex differences in identifying the facial affect of normal and mirror-reversed faces

The influences of sex and lateralized visual hemispace bias in the judgment of the emotional valence of faces during a free viewing condition are evaluated. 73 subjects (aged 18 to 52 yr.) viewed videotaped facial expressions of emotion in normal and mirror-reversed orientation and classified each face as a positive, negative, or neutral expression. There was a significant interaction between the sex of the rater and the orientation of the face that influenced the proportion of correct classifications. Male and female perceivers did not differ in the accuracy of their affect judgments for faces viewed in normal orientation, whereas reversal of the orientation of the faces resulted in a significant enhancement of accuracy judgments for the males but not the females. The results suggest greater cerebral lateralization of perceptual processes in males.     

What aspects of face processing are impaired in developmental prosopagnosia?

Developmental prosopagnosia (DP) is a severe impairment in identifying faces that is present from early in life and that occurs despite no apparent brain damage and intact visual and intellectual function. Here, we investigated what aspects of face processing are impaired/spared in developmental prosopagnosia by examining a relatively large group of individuals with DP (n = 8) using an extensive battery of well-established tasks. The tasks included measures of sensitivity to global motion and to global form, detection that a stimulus is a face, determination of its sex, holistic face processing, processing of face identity based on features, contour, and the spacing of features, and judgments of attractiveness. The DP cases showed normal sensitivity to global motion and global form and performed normally on our tests of face detection and holistic processing. On the other tasks, many DP cases were impaired but there was no systematic pattern. At least half showed deficits in processing of facial identity based on either the outer contour or spacing of the internal features, and/or on judgments of attractiveness. Three of the eight were impaired in processing facial identify based on the shape of internal features. The results show that DP is a heterogeneous condition and that impairment in recognizing faces cannot be predicted by poor performance on any one measure of face processing.     

Face aftereffects suggest interdependent processing of expression and sex and of expression and race

Bruce and Young (1986) proposed that functionally different aspects of faces (e.g., sex, identity, and expression) are processed independently. Although interdependent processing of identity and expression and of identity and sex have been demonstrated previously, evidence for interdependent processing of sex and expression is equivocal. Using a visual adaptation paradigm, we show that expression aftereffects can be simultaneously induced in different directions along anger–fear continua for male and female faces (Experiment 1) and for East Asian and Black African faces (Experiment 2). These findings for sex- and race-contingent expression aftereffects suggest that processing of expression is interdependent with processing of sex and race and are therefore problematic for models of face perception that have emphasized independent processing of functionally different aspects of faces. By contrast, our findings are consistent with models of face processing that propose that invariant physical aspects of faces and changeable social cues can be processed interdependently.     

Evaluating the independence of sex and expression in judgments of faces

Face recognition models suggest independent processing for functionally different types of information, such as identity, expression, sex, and facial speech. Interference between sex and expression information was tested using both a rating study and Garner's selective attention paradigm using speeded sex and expression decisions. When participants were asked to assess the masculinity of male and female angry and surprised faces, they found surprised faces to be more feminine than angry ones (Experiment 1). However, in a speeded-classification situation in the laboratory in which the sex decision was either "easy" relative to the expression decision (Experiment 2) or of more equivalent difficulty (Experiment 3), it was possible for participants to attend selectively to either dimension without interference from the other. Qualified support is offered for independent processing routes.     

Perceptual biases in processing facial identity and emotion

Normal observers demonstrate a bias to process the left sides of faces during perceptual judgments about identity or emotion. This effect suggests a right cerebral hemisphere processing bias. To test the role of the right hemisphere and the involvement of configural processing underlying this effect, young and older control observers and patients with right hemisphere damage completed two chimeric faces tasks (emotion judgment and face identity matching) with both upright and inverted faces. For control observers, the emotion judgment task elicited a strong left-sided perceptual bias that was reduced in young controls and eliminated in older controls by face inversion. Right hemisphere damage reversed the bias, suggesting the right hemisphere was dominant for this task, but that the left hemisphere could be flexibly recruited when right hemisphere mechanisms are not available or dominant. In contrast, face identity judgments were associated most clearly with a vertical bias favouring the uppermost stimuli that was eliminated by face inversion and right hemisphere lesions. The results suggest these tasks involve different neurocognitive mechanisms. The role of the right hemisphere and ventral cortical stream involvement with configural processes in face processing is discussed.     

The relationships between processing facial identity,emotional expression,facial speech,and gaze direction during development

Four experiments were conducted with 5- to 11-year-olds and adults to investigate whether facial identity, facial speech, emotional expression, and gaze direction are processed independently of or in interaction with one another. In a computer-based, speeded sorting task, participants sorted faces according to facial identity while disregarding facial speech, emotional expression, and gaze direction or, alternatively, according to facial speech, emotional expression, and gaze direction while disregarding facial identity. Reaction times showed that children and adults were able to direct their attention selectively to facial identity despite variations of other kinds of face information, but when sorting according to facial speech and emotional expression, they were unable to ignore facial identity. In contrast, gaze direction could be processed independently of facial identity in all age groups. Apart from shorter reaction times and fewer classification errors, no substantial change in processing facial information was found to be correlated with age. We conclude that adult-like face processing routes are employed from 5 years of age onward.     

The role of holistic processing in judgments of facial attractiveness

Previous work has demonstrated that facial identity recognition, expression recognition, gender categorisation, and race categorisation rely on a holistic representation. Here we examine whether a holistic representation is also used for judgments of facial attractiveness. Like past studies, we used the composite paradigm to assess holistic processing (Young et al 1987, Perception 16 747-759). Experiment 1 showed that top halves of upright faces are judged to be more attractive when aligned with an attractive bottom half than when aligned with an unattractive bottom half. To assess whether this effect resulted from holistic processing or more general effects, we examined the impact of the attractive and unattractive bottom halves when upright halves were misaligned and when aligned and misaligned halves were presented upside-down. The bottom halves had no effect in either condition. These results demonstrate that the perceptual processes underlying upright facial-attractiveness judgments represent the face holistically. Our findings with attractiveness judgments and previous demonstrations involving other aspects of face processing suggest that a common holistic representation is used for most types of face processing.     

Sex, sexual orientation, and identification of positive and negative facial affect

Sex and sexual orientation related differences in processing of happy and sad facial emotions were examined using an experimental facial emotion recognition paradigm with a large sample (N = 240). Analysis of covariance (controlling for age and IQ) revealed that women (irrespective of sexual orientation) had faster reaction times than men for accurate identification of facial emotion and were more accurate in identifying male faces than female ones, whereas men performed the same regardless of the sex of the face. However, there were no overall sex differences in accuracy. These findings suggest a limited role for sex in the perception of facial affect.