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.     

Perceiving facial expressions

Three experiments investigated the perception of facial displays of emotions. Using a morphing technique, Experiment 1 (identification task) and Experiment 2 (ABX discrimination task) evaluated the merits of categorical and dimensional models of the representation of these stimuli. We argue that basic emotions—as they are usually defined verbally—do not correspond to primary perceptual categories emerging from the visual analysis of facial expressions. Instead, the results are compatible with the hypothesis that facial expressions are coded in a continuous anisotropic space structured by valence axes. Experiment 3 (identification task) introduces a new technique for generating chimeras to address the debate between feature-based and holistic models of the processing of facial expressions. Contrary to the pure holistic hypothesis, the results suggest that an independent assessment of discrimination features is possible, and may be sufficient for identifying expressions even when the global facial configuration is ambiguous. However, they also suggest that top-down processing may improve identification accuracy by assessing the coherence of local features.     

Categorization and understanding of facial expressions in 4‐month‐old infants

This study examined whether 4‐month‐olds (N = 40) could perceptually categorize happy and angry faces, and show appropriate behavior in response to these faces. During the habituation phase, infants were shown the same type of facial expressions (happy or angry) posed by three models, and their behavior in response to those faces was observed. During the test phase immediately after the habituation phase, infants saw a novel emotional expression and a familiar expression posed by a new model, and their looking times were measured. The results indicated that, although 4‐month‐olds could perceptually categorize happy and angry faces accurately, they responded positively to both expression types. These findings suggest that, although infants can perceptually categorize facial expressions at 4 months of age, they require further time to learn the affective meanings of the facial expressions.     

Discrimination and categorization of emotional facial expressions and faces in Parkinson's disease

Our objective was to compare the ability to discriminate and categorize emotional facial expressions (EFEs) and facial identity characteristics (age and/or gender) in a group of 53 individuals with Parkinson's disease (PD) and another group of 53 healthy subjects. On the one hand, by means of discrimination and identification tasks, we compared two stages in the visual recognition process that could be selectively affected in individuals with PD. On the other hand, facial expression versus gender and age comparison permits us to contrast whether the emotional or non‐emotional content influences the configural perception of faces. In Experiment I, we did not find differences between groups, either with facial expression or age, in discrimination tasks. Conversely, in Experiment II, we found differences between the groups, but only in the EFE identification task. Taken together, our results indicate that configural perception of faces does not seem to be globally impaired in PD. However, this ability is selectively altered when the categorization of emotional faces is required. A deeper assessment of the PD group indicated that decline in facial expression categorization is more evident in a subgroup of patients with higher global impairment (motor and cognitive). Taken together, these results suggest that the problems found in facial expression recognition may be associated with the progressive neuronal loss in frontostriatal and mesolimbic circuits, which characterizes PD.     

Development of category formation for faces differing by age in 9‐ to 12‐month‐olds: An effect of experience with infant faces

We examined category formation for faces differing in age in 9‐ and 12‐month‐olds, and the influence of exposure to infant faces on such ability. Infants were familiarized with adult or infant faces, and then tested with a novel exemplar from the familiarized category paired with a novel exemplar from a novel category (Experiment 1). Both age groups formed discrete categories of adult and infant faces, but exposure to infant faces in everyday life did not modulate performance. The same task was conducted with child versus infant faces (Experiment 2). Whereas 9‐month‐olds preferred infant faces after familiarization with child faces, but not child faces after familiarization with infant faces, 12‐month‐olds formed discrete categories of child and infant faces. Moreover, more exposure to infant faces correlated with higher novel category preference scores when infants were familiarized with infant faces in 12‐month‐olds, but not 9‐month‐olds. The 9‐month‐old asymmetry did not reflect spontaneous preference for infant over child faces (Experiment 3). These findings indicate that 9‐ and 12‐month‐olds can form age‐based categories of faces. The ability of 12‐month‐olds to form separate child and infant categories suggests that they have a more exclusive representation of face age, one that may be influenced by prior experience with infant faces.     

Holistic processing for faces and cars in preschool‐aged children and adults: evidence from the composite effect

The current study compared the development of holistic processing for faces and non‐face visual objects by testing for the composite effect for faces and frontal images of cars in 3‐ to 5‐year‐old children and adults in a series of four experiments using a two‐alternative forced‐choice recognition task. Results showed that a composite effect for faces was present as early as years, and none of the age groups tested showed signs of a composite effect for cars. These findings provide the first demonstration that holistic processing is already selective for faces in early childhood, and confirm existing evidence that sensitivity to holistic information in faces does not increase from 4 years to adulthood.     

Sensitivity to First‐Order Relations of Facial Elements in Infant Rhesus Macaques

Faces are visually attractive to both human and nonhuman primates. Human neonates are thought to have a broad template for faces at birth and prefer face‐like to non‐face‐like stimuli. To better compare developmental trajectories of face processing phylogenetically, here, we investigated preferences for face‐like stimuli in infant rhesus macaques using photographs of real faces. We presented infant macaques aged 15–25 days with human, macaque and abstract faces with both normal and linear arrangements of facial features and measured infants' gaze durations, number of fixations and latency to look to each face using eye‐tracking technology. There was an overall preference for normal over linear facial arrangements for abstract and monkey faces but not human faces. Moreover, infant macaques looked less at monkey faces than at abstract or human faces. These results suggest that species and facial configurations affect face processing in infant macaques, and we discuss potential explanations for these findings. Further, carefully controlled studies are required to ascertain whether infant macaques' face template can be considered as broad as human infants' face template. Copyright © 2013 John Wiley & Sons, Ltd.     

The movement of internal facial features elicits 7 to 8‐month‐old infants' preference for face patterns

A preference for static face patterns is observed in newborns and disappears around 3 months after birth. A previous study has demonstrated that 5‐month‐old infants prefer schematic faces only when the internal features are moving, suggesting that face‐specific movement enhances infants' preference. The present study investigates the facilitative effect of the movement of internal facial features on infants' preference. To examine infants' preference, we used animated face patterns consisting of a head‐shaped contour and three disk blobs. The inner blobs expanded and contracted to represent the opening and closing of the eyes and mouth, and were constrained to open and close only in a biologically possible vertical direction resembling the facial muscle structure. We compared infants' preferential looking time for this vertically moving (VM) face pattern with their looking time for a horizontally moving (HM) face pattern in which blobs transformed at the same speed in a biologically impossible, horizontal direction. In Experiment 1, 7 to 8‐month‐olds preferred the VM to the HM, but 5 to 6‐month‐olds did not. However, the preference was diminished in both cases when the moving face patterns were presented without contour (Experiment 2). Our results suggest that internal facial features with vertical movements promote face preference in 7 to 8‐month‐olds. Copyright © 2011 John Wiley & Sons, Ltd.     

Learning categories by touch: On the development of holistic and analytic processing

The development of holistic and analytic processing often studied in the visual domain was investigated in haptics. Children 3 to 9 years of age and adults had to categorize haptic exemplars that varied systematically in four attributes (size, shape, surface texture, and weight). The subjects could learn the categories either analytically--that is, by focusing on a single attribute--or holistically--that is, in terms of overall similarity. The data show that even the youngest children learned the haptic categories far more often in an analytic mode than in a holistic mode. Nevertheless, an age trend was observed, referring to the attributes that the analytic learners used for their categorization. The children preferred substance-related attributes, especially surface texture, whereas the adults preferred structure-related attributes, especially shape. Thus, it appears that analytic and/or holistic processing in category learning develops in a similar manner in the visual and haptic domains.     

面孔吸引力的整体表征及其动态性增强

面孔作为一种高级的视觉刺激,在人际交往中有着无可替代的作用。其中,面孔吸引力更是影响着日常生活的重要社交决策,如择偶、交友、求职、社会交换等。长久以来,研究者们从面孔特征、社会信息和观察者因素等角度不断探索着人们对静态面孔吸引力的感知,且多从进化角度加以解释。但是,人们如何表征面孔吸引力以及其动态性增强机制仍未可知。本项目通过两个研究,分别从面孔吸引力的整体表征,以及面孔动态性通过影响整体加工、影响对整体信息和特征信息的注意、以及影响社会信息来增强吸引力,从这两个角度尝试回答这一问题。在研究1中,本项目从整体加工的角度探索了面孔吸引力的认知表征。研究1.1通过评分任务和适应范式探索高空间频率（更多局部特征）和低空间频率（更多整体特征）对面孔吸引力的影响,旨在从空间频率探讨面孔吸引力的整体表征。研究1.2通过操纵面孔对称性和面孔常态性探索面孔常态性在面孔对称性和面孔吸引力间的中介作用,探讨面孔吸引力的常态构型表征。研究1.3引入“三庭五眼”这一中国传统面孔审美理论,通过评分任务和适应范式研究“三庭五眼” 构型是否符合中国人对高吸引力中国面孔的表征,以此探讨面孔吸引力的整体表征。研究1.4通过评分任务和适应范式考察局部面孔遮挡是否促进整体面孔吸引力,以及这种促进作用是否由于人们通过局部特征“脑补”出了完整面孔。研究2从整体加工、注意和生命力的角度探讨面孔吸引力的动态性增强机制。研究2.1使用合成效应范式测量动态面孔吸引力的整体加工,探索动静态面孔的吸引力差异是否源于其整体加工程度的不同。研究2.2使用注意分散范式,并结合眼动技术,探讨人们对动静态面孔的注视模式是否存在差异,这种差异是否能解释动态面孔吸引力的增强。研究2.3结合问卷法、实验法和结构方程模型,考察了生命力这一社会因素对动静态面孔吸引力的影响。本项目探讨了面孔吸引力的认知表征以及其动态性增强机制,有助于我们进一步理解人们对面孔吸引力的认知加工以及人类欣赏美这一高级智能。同时,本项目的结果对于日常人际交往和面孔吸引力相关算法的优化等方面也有潜在的应用价值。     

Brain activation during upright and inverted encoding of own‐ and other‐age faces: ERP evidence for an own‐age bias

We investigated the neural processing underlying own‐age versus other‐age faces among 5‐year‐old children and adults, as well as the effect of orientation on face processing. Upright and inverted faces of 5‐year‐old children, adults, and elderly adults (> 75 years of age) were presented to participants while ERPs and eye tracking patterns were recorded concurrently. We found evidence for an own‐age bias in children, as well as for predicted delayed latencies and larger amplitudes for inverted faces, which replicates earlier findings. Finally, we extend recent reports about an expert‐sensitive component (P2) to other‐race faces to account for similar effects in regard to other‐age faces. We conclude that differences in neural activity are strongly related to the amount and quality of experience that participants have with faces of various ages. Effects of orientation are discussed in relation to the holistic hypothesis and recent data that compromise this view.     

Developmental changes in the recognition of faces and facial features

The view that, as children get older, there is a decline in the use of feature‐based forms of face processing to more configurational forms of processing was examined by asking 6‐year‐old and 9‐year‐old children to judge which of two photographs matches an identical probe photograph. The probe and test stimuli were either photographs of whole faces or photographs of isolated facial features. Within this standard method, the stimuli also systematically varied in terms of the familiarity of the faces shown and in the orientation of presentation, both factors that have been interpreted as effecting configurational encoding. A number of age‐related effects are observed: (a) older children are better at recognizing whole faces than younger children, (b) older children exhibit a clear face inversion effect with whole faces while the younger children are equally adept at identifying upright and inverted whole faces, and (c) analysis of the recognition rates associated with the individual features reveals that younger children are better than older children when asked to recognize eye regions. It is argued that the data support the view that as children get older there is a change in the forms of piecemeal encoding employed and an increase in configurational processing. Copyright © 2000 John Wiley & Sons, Ltd.     

Effect of facial stimuli exposure time on evaluation of facial attractiveness

Facial attractiveness has advantages both socially and sexually, and the human brain has evolved to perceive specific facial characteristics as attractive. The current research examined the effect of facial stimuli exposure time on facial attractiveness evaluations. In Experiment 1, 86 students observed 44 facial stimuli in short and long amounts of time. To eliminate any influence of repeated stimuli on the second observations, Experiment 2 was performed on 84 participants who observed the facial stimuli in either short or long durations. Differences in both experiments were significant. These studies showed that exposure time has an influence on the evaluation of facial attractiveness. Participants who were exposed to facial stimuli for a short amount of time perceived greater facial attractiveness than when they were exposed for a longer time to the same stimuli. In other words, faces were more beautiful when they were observed in a short amount of time, and this effect occurred regardless of gender.     

The flip side of the other‐race coin: They all look different to me

Poorer recognition of other‐race faces than own‐races faces has been attributed to a problem of discrimination (i.e., telling faces apart). The conclusion that ‘they all look the same to me' is based on studies measuring the perception/memory of highly controlled stimuli, typically involving only one or two images of each identity. We hypothesized that such studies underestimate the challenge involved in recognizing other‐race faces because in the real world, an individual's appearance varies in a number of ways (e.g., lighting, expression, hairstyle), reducing the utility of relying on pictorial cues to identity. In two experiments, Caucasian and East Asian participants completed a perceptual sorting task in which they were asked to sort 40 photographs of two unfamiliar identities into piles such that each pile contained all photographs of a single identity. Participants perceived more identities when sorting other‐race faces than own‐race faces, both when sorting celebrity (Experiment 1) and non‐celebrity (Experiment 2) faces, suggesting that in the real world, ‘they all look different to me'. We discuss these results in the light of models in which each identity is represented as a region in a multidimensional face space; we argue that this region is smaller for other‐race than own‐race faces.     

Normal perception of Mooney faces in developmental prosopagnosia: Evidence from the N170 component and rapid neural adaptation

Individuals with developmental prosopagnosia (DP) have a severe difficulty recognizing the faces of known individuals in the absence of any history of neurological damage. These recognition problems may be linked to selective deficits in the holistic/configural processing of faces. We used two‐tone Mooney images to study the processing of faces versus non‐face objects in DP when it is based on holistic information (or the facial gestalt) in the absence of obvious local cues about facial features. A rapid adaptation procedure was employed for a group of 16 DPs. Naturalistic photographs of upright faces were preceded by upright or inverted Mooney faces or by Mooney houses. DPs showed face‐sensitive N170 components in response to Mooney faces versus houses, and N170 amplitude reductions for inverted as compared to upright Mooney faces. They also showed the typical pattern of N170 adaptation effects, with reduced N170 components when upright naturalistic test faces were preceded by upright Mooney faces, demonstrating that the perception of Mooney and naturalistic faces recruits shared neural populations. Our findings demonstrate that individuals with DP can utilize global information about face configurations for categorical discriminations between faces and non‐face objects, and suggest that face processing deficits emerge primarily at more fine‐grained higher level stages of face perception.     

The perception of (naked only) bodies and faceless heads relies on holistic processing: Evidence from the inversion effect

Faces and bodies are more difficult to perceive when presented inverted than when presented upright (i.e., stimulus inversion effect), an effect that has been attributed to the disruption of holistic processing. The features that can trigger holistic processing in faces and bodies, however, still remain elusive. In this study, using a sequential matching task, we tested whether stimulus inversion affects various categories of visual stimuli: faces, faceless heads, faceless heads in body context, headless bodies naked, whole bodies naked, headless bodies clothed, and whole bodies clothed. Both accuracy and inversion efficiency score results show inversion effects for all categories but for clothed bodies (with and without heads). In addition, the magnitude of the inversion effect for face, naked body, and faceless heads was similar. Our findings demonstrate that the perception of faces, faceless heads, and naked bodies relies on holistic processing. Clothed bodies (with and without heads), on the other side, may trigger clothes-sensitive rather than body-sensitive perceptual mechanisms.     

Differences in holistic processing do not explain cultural differences in the recognition of facial expression

The aim of this study was to investigate the causes of the own-race advantage in facial expression perception. In Experiment 1, we investigated Western Caucasian and Chinese participants’ perception and categorization of facial expressions of six basic emotions that included two pairs of confusable expressions (fear and surprise; anger and disgust). People were slightly better at identifying facial expressions posed by own-race members (mainly in anger and disgust). In Experiment 2, we asked whether the own-race advantage was due to differences in the holistic processing of facial expressions. Participants viewed composite faces in which the upper part of one expression was combined with the lower part of a different expression. The upper and lower parts of the composite faces were either aligned or misaligned. Both Chinese and Caucasian participants were better at identifying the facial expressions from the misaligned images, showing interference on recognizing the parts of the expressions created by holistic perception of the aligned composite images. However, this interference from holistic processing was equivalent across expressions of own-race and other-race faces in both groups of participants. Whilst the own-race advantage in recognizing facial expressions does seem to reflect the confusability of certain emotions, it cannot be explained by differences in holistic processing.     

Vulnerability to disease is associated with a domain‐specific preference for symmetrical faces relative to symmetrical non‐face stimuli

Two experiments tested the hypothesis that the accessibility of disease concerns would be associated with a preference for faces high in symmetry, a cue to good health and pathogen resistance. Disease concerns (perceived vulnerability to disease) were measured as an individual difference in Experiment 1 and were situationally primed in Experiment 2. Across both studies, heightened disease sensitivity predicted a preference for symmetrical faces. Importantly, this increased preference for symmetrical faces when disease threats were salient did not generalize to non‐face stimuli. These results suggest a domain‐specific preference for symmetry in human faces, an adaptive response due to the ability of faces to signal resistance to infectious diseases in individuals and situations where disease is a salient threat. Copyright © 2011 John Wiley & Sons, Ltd.     

Emotional context at learning systematically biases memory for facial information

Emotion influences memory in many ways. For example, when a mood-dependent processing shift is operative, happy moods promote global processing and sad moods direct attention to local features of complex visual stimuli. We hypothesized that an emotional context associated with to-be-learned facial stimuli could preferentially promote global or local processing. At learning, faces with neutral expressions were paired with a narrative providing either a happy or a sad context. At test, faces were presented in an upright or inverted orientation, emphasizing configural or analytical processing, respectively. A recognition advantage was found for upright faces learned in happy contexts relative to those in sad contexts, whereas recognition was better for inverted faces learned in sad contexts than for those in happy contexts. We thus infer that a positive emotional context prompted more effective storage of holistic, configural, or global facial information, whereas a negative emotional context prompted relatively more effective storage of local or feature-based facial information