An 'other-race effect' for categorizing faces by sex

Event-related potential correlates of implicit processing of own- and other-race faces in children

Human adults typically experience difficulties in recognizing and discriminating individual faces belonging to racial groups other than their own. The origin of this "other-race" effect is set in infancy, but the understanding of its developmental course is fragmented. We aimed to access the mechanisms of the other-race effect in childhood by unraveling the neural time course of own- and other-race face processing during a masked priming paradigm. White 6- and 7-year-old children (N = 19) categorized fully visible Asian (other-race) or White (own-race) target faces according to gender. Target faces were preceded by masked same-identity or different-identity prime faces, matching the target for race and gender. We showed an early priming effect on the N100 component, with larger amplitude to different-face pairs than to same-face pairs, and a later race effect on the N200 component, with larger amplitude to own-race face pairs than to other-race face pairs. Critically, race did not interact with priming at any processing stage (P100, N100, P200, N200, or P300). Our results suggest that race could have a temporally limited impact on face processing and that the implicit and unconscious identity processing of own- and other-race faces could be similar in 6- and 7-year-olds, depicting an immature other-race effect during childhood.

Asymmetrical responding to male versus female other-race categories in 9- to 12-month-old infants

Faces can be categorized along various dimensions including gender or race, an ability developing in infancy. Infant categorization studies have focused on facial attributes in isolation, but the interaction between these attributes remains poorly understood. Experiment 1 examined gender categorization of other-race faces in 9- and 12-month-old White infants. Nine- and 12-month-olds were familiarized with Asian male or female faces, and tested with a novel exemplar from the familiarized category paired with a novel exemplar from a novel category. Both age groups showed novel category preferences for novel Asian female faces after familiarization with Asian male faces, but showed no novel category preference for novel Asian male faces after familiarization with Asian female faces. This categorization asymmetry was not due to a spontaneous preference hindering novel category reaction (Experiment 2), and both age groups displayed difficulty discriminating among male, but not female, other-race faces (Experiment 3). These results indicate that category formation for male other-race faces is mediated by categorical perception. Overall, the findings suggest that even by 12 months of age, infants are not fully able to form gender category representations of other-race faces, responding categorically to male, but not female, other-race faces.

Illusory faces are more likely to be perceived as male than female

Face pareidolia is the phenomenon of perceiving illusory faces in inanimate objects. Here we show that illusory faces engage social perception beyond the detection of a face: they have a perceived age, gender, and emotional expression. Additionally, we report a striking bias in gender perception, with many more illusory faces perceived as male than female. As illusory faces do not have a biological sex, this bias is significant in revealing an asymmetry in our face evaluation system given minimal information. Our result demonstrates that the visual features that are sufficient for face detection are not generally sufficient for the perception of female. Instead, the perception of a nonhuman face as female requires additional features beyond that required for face detection.

Despite our fluency in reading human faces, sometimes we mistakenly perceive illusory faces in objects, a phenomenon known as face pareidolia. Although illusory faces share some neural mechanisms with real faces, it is unknown to what degree pareidolia engages higher-level social perception beyond the detection of a face. In a series of large-scale behavioral experiments (n_total = 3,815 adults), we found that illusory faces in inanimate objects are readily perceived to have a specific emotional expression, age, and gender. Most strikingly, we observed a strong bias to perceive illusory faces as male rather than female. This male bias could not be explained by preexisting semantic or visual gender associations with the objects, or by visual features in the images. Rather, this robust bias in the perception of gender for illusory faces reveals a cognitive bias arising from a broadly tuned face evaluation system in which minimally viable face percepts are more likely to be perceived as male.

Own-race faces promote integrated audiovisual speech information

The other-race effect indicates a perceptual advantage when processing own-race faces. This effect has been demonstrated in individuals' recognition of facial identity and emotional expressions. However, it remains unclear whether the other-race effect also exists in multisensory domains. We conducted two experiments to provide evidence for the other-race effect in facial speech recognition, using the McGurk effect. Experiment 1 tested this issue among East Asian adults, examining the magnitude of the McGurk effect during stimuli using speakers from two different races (own-race vs. other-race). We found that own-race faces induced a stronger McGurk effect than other-race faces. Experiment 2 indicated that the other-race effect was not simply due to different levels of attention being paid to the mouths of own- and other-race speakers. Our findings demonstrated that own-race faces enhance the weight of visual input during audiovisual speech perception, and they provide evidence of the own-race effect in the audiovisual interaction for speech perception in adults.

The left-side bias is not unique to own-race face processing

Humans show a clear left-side bias in face processing. A chimeric face constructed with the left side (from the viewer's perspective) of a face and its mirror image is usually rated as more resemblant to the original face than a chimeric face constructed with the right side of the same face. Previous studies have characterized the left-side bias mainly with own-race faces, but it remains unclear whether this effect is race specific or if it reflects an universal visual expertise. One hundred and five Chinese students completed two versions of a chimeric face-identification task. The results revealed a significant left-side bias for both own-race (Chinese) and other-race (Caucasian) faces, suggesting that the left-side bias reflects an universal visual expertise in face processing.

Face Adaptation and Face Priming as Tools for Getting Insights Into the Quality of Face Space

During the recognition of faces, the incoming perceptual information is matched against mental representations of familiar faces stored in memory. Face space models describe an abstract concept of face representations and their mental organization, in which facial representations are located on various characteristic dimensions, depending on their specific facial characteristics. However, these models are defined just as incompletely as the general understanding of face recognition. We took two phenomena from face processing to better understand face recognition, and so the nature of face space: face adaptation and face priming. The face literature has mainly focused on face adaptation, largely neglecting face priming when trying to integrate outcomes regarding face recognition into the face space framework. Consequently, the present paper aims to review both phenomena and their contributions to face recognition, representation, and face space.

The Other-Race and Other-Species Effect during a Sex Categorization Task: An Eye Tracker Study

Sex categorization from faces is a crucial ability for humans and non-human primates for various social and cognitive processes. In the current study, we performed two eye tracking experiments to examine the gaze behavior of participants during a sex categorization task in which participants categorize face pictures from their own-race (Caucasian), other-race (Asian) and other-species (chimpanzee). In experiment 1, we presented the faces in an upright position to 16 participants, and found a strong other-race and other-species effect. In experiment 2, the same faces were shown to 24 naïve participants in an upside-down (inverted) position, which showed that, although the other-species effect was intact, other-race effect disappeared. Moreover, eye-tracking analysis revealed that in the upright position, the eye region was the first and most widely viewed area for all face categories. However, during upside-down viewing, participants' attention directed more towards the eye region of the own-race and own-species faces, whereas the nose received more attention in other-race and other-species faces. Overall results suggest that other-race faces were processed less holistically compared to own-race faces and this could affect both participants' behavioral performance and gaze behavior during sex categorization. Finally, gaze data suggests that the gaze of participants shifts from the eye to the nose region with decreased racial and species-based familiarity.

Sex Categorization of Faces: The Effects of Age and Experience

The face own-age bias effect refers to the better ability to recognize the face from one's own age compared with other age groups. Here we examined whether an own-age advantage occurs for faces sex categorization. We examined 7- and 9-year-olds' and adults' ability to correctly categorize the sex of 7- and 9-year-olds and adult faces without external cues, such as hair. Results indicated that all ages easily classify the sex of adult faces. They succeeded in classifying the sex of child faces, but their performance was poorer than for adult faces. In adults, processing time increased, and a response bias (male response) was elicited for child faces. In children, response times remained constant, and no bias was observed. Experience with specific category of faces seems to offer some advantage in speed of processing. Overall, sex categorization is more challenging for child than for adult faces due to their reduced sexual dimorphic facial characteristics.

Personal Identification of Deceased Persons: An Overview of the Current Methods Based on Physical Appearance

The use of the physical appearance of the deceased has become more important because the available antemortem information for comparisons may consist only of a physical description and photographs. Twenty-one articles dealing with the identification based on the physiognomic features of the human body were selected for review and were divided into four sections: (i) visual recognition, (ii) specific facial/body areas, (iii) biometrics, and (iv) dental superimposition. While opinions about the reliability of the visual recognition differ, the search showed that it has been used in mass disasters, even without testing its objectivity and reliability. Specific facial areas being explored for the identification of dead; however, their practical use is questioned, similarly to soft biometrics. The emerging dental superimposition seems to be the only standardized and successfully applied method for identification so far. More research is needed into a potential use of the individualizing features, considering that postmortem changes and technical difficulties may affect the identification.

Perceptual experience shapes our ability to categorize faces by national origin: A new other-race effect

People are better at recognizing own-race than other-race faces. This other-race effect has been argued to be the result of perceptual expertise, whereby face-specific perceptual mechanisms are tuned through experience. We designed new tasks to determine whether other-race effects extend to categorizing faces by national origin. We began by selecting sets of face stimuli for these tasks that are typical in appearance for each of six nations (three Caucasian, three Asian) according to people from those nations (Study 1). Caucasian and Asian participants then categorized these faces by national origin (Study 2). Own-race faces were categorized more accurately than other-race faces. In contrast, Asian American participants, with more extensive other-race experience than the first Asian group, categorized other-race faces better than own-race faces, demonstrating a reversal of the other-race effect. Therefore, other-race effects extend to the ability to categorize faces by national origin, but only if participants have greater perceptual experience with own-race, than other-race faces. Study 3 ruled out non-perceptual accounts by showing that Caucasian and Asian faces were sorted more accurately by own-race than other-race participants, even in a sorting task without any explicit labelling required. Together, our results demonstrate a new other-race effect in sensitivity to national origin of faces that is linked to perceptual expertise.

Facial race and sex cues have a comparable influence on emotion recognition in Chinese and Australian participants

The magnitude of the happy categorisation advantage, the faster recognition of happiness than negative expressions, is influenced by facial race and sex cues. Previous studies have investigated these relationships using racial outgroups stereotypically associated with physical threat in predominantly Caucasian samples. To determine whether these influences generalise to stimuli representing other ethnic groups and to participants of different ethnicities, Caucasian Australian (Experiments 1 and 2) and Chinese participants (Experiment 2) categorised happy and angry expressions displayed on own-race male faces presented with emotional other-race male, own-race female, and other-race female faces in separate tasks. The influence of social category cues on the happy categorisation advantage was similar in the Australian and Chinese samples. In both samples, the happy categorisation advantage was present for own-race male faces when they were encountered with other-race male faces but reduced when own-race male faces were categorised along with female faces. The happy categorisation advantage was present for own-race and other-race female faces when they were encountered with own-race male faces in both samples. Results suggest similarity in the influence of social category cues on emotion categorisation.

Interference among the Processing of Facial Emotion, Face Race, and Face Gender

People can process multiple dimensions of facial properties simultaneously. Facial processing models are based on the processing of facial properties. The current study examined the processing of facial emotion, face race, and face gender using categorization tasks. The same set of Chinese, White and Black faces, each posing a neutral, happy or angry expression, was used in three experiments. Facial emotion interacted with face race in all the tasks. The interaction of face race and face gender was found in the race and gender categorization tasks, whereas the interaction of facial emotion and face gender was significant in the emotion and gender categorization tasks. These results provided evidence for a symmetric interaction between variant facial properties (emotion) and invariant facial properties (race and gender).

Facial Expression Recognition and Social Competence among African American Elementary School Children: An Examination of Ethnic Differences

The purpose of the present study was to investigate the potential for cross-ethnic miscommunication of facial expressions. The ability of elementary school children to identify emotion in African American and European American facial expressions and how this ability relates to social competence was examined. African American (n = 37) and European American (n = 37) children were administered African American and European American faces. Sociometric ratings also were obtained. The ability to read faces differing in ethnicity did not differ by children’s ethnicity. However, ability to read facial expressions of one’s own ethnic group, but not the other, was significantly related to social competence.

An Ingroup Advantage for Confidence in Emotion Recognition Judgments: The Moderating Effect of Familiarity With the Expressions of Outgroup Members

The confidence we have in our assessment of an interaction partner's emotional state can have important consequences for the quality of the interaction. Two studies assessed the hypothesis that immigrants are more confident in their judgment of others' emotional facial expressions if the expresser is a member of their cultural ingroup rather than a member of the host community or another cultural group. In addition, the effects of the perceived familiarity with the type of expression, the length of residence in the host country, the quality of cross-cultural contact, the level of acculturation, and the intensity of the facial expressions were assessed. Overall, the results revealed an ingroup advantage effect for confidence ratings as well as support for the notion that individuals are more confident when judging expressions that they consider as more frequently displayed in everyday life. Furthermore, individuals were more confident when judging happiness expressions as well as more intense expressions in general.

Ethnic Categorisation of Faces is Not Independent of Face Identity

Is the extraction of a visually derived semantic code from faces (ethnicity) affected by face identity (familiarity) or not? The traditional view considers that this operation is made independently of face identity, and in parallel with the recognition of identity. However, some recent studies cast doubt on this parallel thesis regarding other visually derived semantic codes, namely: facial expression, facial speech, apparent age, and gender. Twenty-eight Caucasian participants were enrolled in an ‘ethnic-decision’ task on morphed faces made of an Asiatic source face and a Caucasian source face, in the proportion of 70%–30%. Half of the original faces were previously made familiar by a learning procedure (associating the face, surname, occupation, and city of residence of the person displayed), while the remaining half were unfamiliar. The results showed clearly that ethnic decision was affected by face familiarity. This adds support to the thesis according to which the identification of identity and the extraction of visually derived semantic codes are not made independently from each other and that the ‘parallel-route’ hypothesis becomes weakly supported.

Converging Evidence of Ubiquitous Male Bias in Human Sex Perception

Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception.

Artificial faces are harder to remember

Observers interact with artificial faces in a range of different settings and in many cases must remember and identify computer-generated faces. In general, however, most adults have heavily biased experience favoring real faces over synthetic faces. It is well known that face recognition abilities are affected by experience such that faces belonging to "out-groups" defined by race or age are more poorly remembered and harder to discriminate from one another than faces belonging to the "in-group." Here, we examine the extent to which artificial faces form an "out-group" in this sense when other perceptual categories are matched. We rendered synthetic faces using photographs of real human faces and compared performance in a memory task and a discrimination task across real and artificial versions of the same faces. We found that real faces were easier to remember, but only slightly more discriminable than artificial faces. Artificial faces were also equally susceptible to the well-known face inversion effect, suggesting that while these patterns are still processed by the human visual system in a face-like manner, artificial appearance does compromise the efficiency of face processing.

Effects of visual expertise on a novel eye-size illusion: implications for holistic face processing

We examined the effect of visual experience on the magnitude of a novel eye-size illusion: when the size of a face's frame is increased or decreased but eye size is unchanged, observers judge the size of the eyes to be different from that in the original face frame. In the current study, we asked Chinese and Caucasian participants to judge eye size in different pairs of faces and measured the magnitude of the illusion when the faces were own- or other-age (adult vs. infant faces) and when the faces were own- or other-race (Chinese vs. Caucasian faces). We found an other-age effect and an other-race effect with the eye-size illusion: The illusion was more pronounced with own-race and own-age faces than with other-race and other-age faces. These findings taken together suggest that visual experience with faces influences the magnitude of this novel illusion. Extensive experience with certain face categories strengthens the illusion in the context of these categories, but lack of it reduces the magnitude of the illusion. Our results further imply that holistic processing may play an important role in engendering the eye-size illusion.

Aging affects sex categorization of male and female faces in opposite ways

Faces are rich in social information; they easily give away a person's sex, approximate age, feelings, or focus of attention. Past research has mostly focused on investigating the distinct facial signals and perceptual mechanisms that allow us to categorize faces on these individual dimensions. It is less well understood how the different kinds of facial information interact. Here we investigated how the age of a face affects the ease with which young and older adults categorize its sex. Disconfirming everyday intuition, we showed that sex categorization is not generally hampered for older faces. Although categorization of female faces took progressively more time with increasing age, the opposite was found for male faces (Experiment 1). Differential effects of stimulus blurring and inversion for male and female faces of different ages (Experiment 2) strongly suggest one feature as a crucial mediator of the interdependence of age and sex perception - skin texture.

The effects of a culturally gender-specifying peripheral cue (headscarf) on the categorization of faces by gender

Faces convey a wealth of cues that influence social categorizations and subsequent cognition and behavior. This study examined the effects of wearing a headscarf on face categorization by gender using Egyptian observers who have an extensive exposure with headscarf-framed female faces. A typical headscarf (worn by females) enhanced perceived femininity whereas an atypical headscarf (worn by males) reduced perceived masculinity. Regardless of whether the faces were presented briefly, or until participants responded, the typical headscarf had no effect on categorizing female faces but the atypical headscarf greatly slowed down categorizing male faces. However, a typical headscarf advantage was noticed when the atypical headscarf condition was removed. In addition, both typical and atypical headscarf effects were greatly strengthened when faces were presented as negatives. These data provide support to the dynamic continuity account of social categorization that suggests a competition among multiple simultaneous representations until a construal is stabilized.

Asian infants show preference for own-race but not other-race female faces: the role of infant caregiving arrangements

Previous studies have reported that 3- to 4-month-olds show a visual preference for faces of the same gender as their primary caregiver (e.g., Quinn et al., 2002). In addition, this gender preference has been observed for own-race faces, but not for other-race faces (Quinn et al., 2008). However, most of the studies of face gender preference have focused on infants at 3–4 months. Development of gender preference in later infancy is still unclear. Moreover, all of these studies were conducted with Caucasian infants from Western countries. It is thus unknown whether a gender preference that is limited to own-race faces can be generalized to infants from other racial groups and different cultures with distinct caregiving practices. The current study investigated the face gender preferences of Asian infants presented with male versus female face pairs from Asian and Caucasian races at 3, 6, and 9 months and the role of caregiving arrangements in eliciting those preferences. The results showed an own-race female face preference in 3- and 6-month-olds, but not in 9-month-olds. Moreover, the downturn in the female face preference correlated with the cumulative male face experience obtained in caregiving practices. In contrast, no gender preference or correlation between gender preference and face experience was found for other-race Caucasian faces at any age. The data indicate that the face gender preference is not specifically rooted in Western cultural caregiving practices. In addition, the race dependency of the effect previously observed for Caucasian infants reared by Caucasian caregivers looking at Caucasian but not Asian faces extends to Asian infants reared by Asian caregivers looking at Asian but not Caucasian faces. The findings also provide additional support for an experiential basis for the gender preference, and in particular suggest that cumulative male face experience plays a role in inducing a downturn in the preference in older infants.

Angry facial expressions bias gender categorization in children and adults: behavioral and computational evidence

Angry faces are perceived as more masculine by adults. However, the developmental course and underlying mechanism (bottom-up stimulus driven or top-down belief driven) associated with the angry-male bias remain unclear. Here we report that anger biases face gender categorization toward “male” responding in children as young as 5–6 years. The bias is observed for both own- and other-race faces, and is remarkably unchanged across development (into adulthood) as revealed by signal detection analyses (Experiments 1–2). The developmental course of the angry-male bias, along with its extension to other-race faces, combine to suggest that it is not rooted in extensive experience, e.g., observing males engaging in aggressive acts during the school years. Based on several computational simulations of gender categorization (Experiment 3), we further conclude that (1) the angry-male bias results, at least partially, from a strategy of attending to facial features or their second-order relations when categorizing face gender, and (2) any single choice of computational representation (e.g., Principal Component Analysis) is insufficient to assess resemblances between face categories, as different representations of the very same faces suggest different bases for the angry-male bias. Our findings are thus consistent with stimulus-and stereotyped-belief driven accounts of the angry-male bias. Taken together, the evidence suggests considerable stability in the interaction between some facial dimensions in social categorization that is present prior to the onset of formal schooling.

Influence of skin ageing features on Chinese women's perception of facial age and attractiveness

OBJECTIVES

Ageing leads to characteristic changes in the appearance of facial skin. Among these changes, we can distinguish the skin topographic cues (skin sagging and wrinkles), the dark spots and the dark circles around the eyes. Although skin changes are similar in Caucasian and Chinese faces, the age of occurrence and the severity of age-related features differ between the two populations. Little is known about how the ageing of skin influences the perception of female faces in Chinese women. The aim of this study is to evaluate the contribution of the different age-related skin features to the perception of age and attractiveness in Chinese women.

METHODS

Facial images of Caucasian women and Chinese women in their 60s were manipulated separately to reduce the following skin features: (i) skin sagging and wrinkles, (ii) dark spots and (iii) dark circles. Finally, all signs were reduced simultaneously (iv). Female Chinese participants were asked to estimate the age difference between the modified and original images and evaluate the attractiveness of modified and original faces.

RESULTS

Chinese women perceived the Chinese faces as younger after the manipulation of dark spots than after the reduction in wrinkles/sagging, whereas they perceived the Caucasian faces as the youngest after the manipulation of wrinkles/sagging. Interestingly, Chinese women evaluated faces with reduced dark spots as being the most attractive whatever the origin of the face. The manipulation of dark circles contributed to making Caucasian and Chinese faces being perceived younger and more attractive than the original faces, although the effect was less pronounced than for the two other types of manipulation.

CONCLUSION

This is the first study to have examined the influence of various age-related skin features on the facial age and attractiveness perception of Chinese women. The results highlight different contributions of dark spots, sagging/wrinkles and dark circles to their perception of Chinese and Caucasian faces.

Sequential effects in judgements of attractiveness: the influences of face race and sex

In perceptual decision-making, a person’s response on a given trial is influenced by their response on the immediately preceding trial. This sequential effect was initially demonstrated in psychophysical tasks, but has now been found in more complex, real-world judgements. The similarity of the current and previous stimuli determines the nature of the effect, with more similar items producing assimilation in judgements, while less similarity can cause a contrast effect. Previous research found assimilation in ratings of facial attractiveness, and here, we investigated whether this effect is influenced by the social categories of the faces presented. Over three experiments, participants rated the attractiveness of own- (White) and other-race (Chinese) faces of both sexes that appeared successively. Through blocking trials by race (Experiment 1), sex (Experiment 2), or both dimensions (Experiment 3), we could examine how sequential judgements were altered by the salience of different social categories in face sequences. For sequences that varied in sex alone, own-race faces showed significantly less opposite-sex assimilation (male and female faces perceived as dissimilar), while other-race faces showed equal assimilation for opposite- and same-sex sequences (male and female faces were not differentiated). For sequences that varied in race alone, categorisation by race resulted in no opposite-race assimilation for either sex of face (White and Chinese faces perceived as dissimilar). For sequences that varied in both race and sex, same-category assimilation was significantly greater than opposite-category. Our results suggest that the race of a face represents a superordinate category relative to sex. These findings demonstrate the importance of social categories when considering sequential judgements of faces, and also highlight a novel approach for investigating how multiple social dimensions interact during decision-making.

UNSUPERVISED DISCOVERY OF VISUAL FACE CATEGORIES

Human faces can be arranged into different face categories using information from common visual cues such as gender, ethnicity, and age. It has been demonstrated that using face categorization as a precursor step to face recognition improves recognition rates and leads to more graceful errors. Although face categorization using common visual cues yields meaningful face categories, developing accurate and robust gender, ethnicity, and age categorizers is a challenging issue. Moreover, it limits the overall number of possible face categories and, in practice, yields unbalanced face categories which can compromise recognition performance. This paper investigates ways to automatically discover a categorization of human faces from a collection of unlabeled face images without relying on predefined visual cues. Specifically, given a set of face images from a group of known individuals (i.e., gallery set), our goal is finding ways to robustly partition the gallery set (i.e., face categories). The objective is being able to assign novel images of the same individuals (i.e., query set) to the correct face category with high accuracy and robustness. To address the issue of face category discovery, we represent faces using local features and apply unsupervised learning (i.e., clustering). To categorize faces in novel images, we employ nearest-neighbor algorithms or learn the separating boundaries between face categories using supervised learning (i.e., classification). To improve face categorization robustness, we allow face categories to share local features as well as to overlap. We demonstrate the performance of the proposed approach through extensive experiments and comparisons using the FERET database.

Biological Sex Determines Whether Faces Look Real

Judging whether a face is real or artificial can be done relatively rapidly and accurately, even when visual information is substantially impoverished. The perception of animacy in the face also has several interesting properties that may reflect both the underlying "tuning" of face space to preferentially represent real face appearance and the diagnosticity of individual features for categorizing faces as animate or inanimate. In the current study, we examined how sex categories interact with animacy perception by separately characterizing animacy judgments as a function of stimulus sex. We find that stimulus sex affects subjective ratings of animacy and sex categorization of real and artificial faces. Specifically, female faces look more artificial and artificial faces look more female. We discuss our results in terms of the ecology of real and artificial faces and the possible role of visual experience with artificial female faces, and the objectification of female faces.

RACE CLASSIFICATION FROM FACE IMAGES USING LOCAL DESCRIPTORS

This paper investigates and compares the performance of local descriptors for race classification from face images. Two powerful types of local descriptors have been considered in this study: Local Binary Patterns (LBP) and Weber Local Descriptors (WLD). First, we investigate the performance of LBP and WLD separately and experiment with different parameter values to optimize race classification. Second, we apply the Kruskal-Wallis feature selection algorithm to select a subset of more "discriminative" bins from the LBP and WLD histograms. Finally, we fuse LBP and WLD, both at the feature and score levels, to further improve race classification accuracy. For classification, we have considered the minimum distance classifier and experimented with three distance measures: City-block, Euclidean, and Chi-square. We have performed extensive experiments and comparisons using five race groups from the FERET database. Our experimental results indicate that (i) using the Kruskal-Wallis feature selection, (ii) fusing LBP with WLD at the feature level, and (iii) using the City-block distance for classification, outperforms LBP and WLD alone as well as methods based on holistic features such as Principal Component Analysis (PCA) and LBP or WLD (i.e., applied globally).

Cultural differences in affect intensity perception in the context of advertising

Cultural differences in the perception of positive affect intensity within an advertising context were investigated among American, Japanese, and Russian participants. Participants were asked to rate the intensity of facial expressions of positive emotions, which displayed either subtle, low intensity, or salient, high intensity expressions of positive affect. In agreement with previous findings from cross-cultural psychological research, current results demonstrate both cross-cultural agreement and differences in the perception of positive affect intensity across the three cultures. Specifically, American participants perceived high arousal (HA) images as significantly less calm than participants from the other two cultures, while the Japanese participants perceived low arousal (LA) images as significantly more excited than participants from the other cultures. The underlying mechanisms of these cultural differences were further investigated through difference scores that probed for cultural differences in perception and categorization of positive emotions. Findings indicate that rating differences are due to (1) perceptual differences in the extent to which HA images were discriminated from LA images, and (2) categorization differences in the extent to which facial expressions were grouped into affect intensity categories. Specifically, American participants revealed significantly higher perceptual differentiation between arousal levels of facial expressions in high and intermediate intensity categories. Japanese participants, on the other hand, did not discriminate between high and low arousal affect categories to the same extent as did the American and Russian participants. These findings indicate the presence of cultural differences in underlying decoding mechanisms of facial expressions of positive affect intensity. Implications of these results for global advertising are discussed.

Facial determinants of female gender and feminizing forehead cranioplasty

OBJECTIVE/HYPOTHESIS

Information determined by viewing a face includes familiarity, emotion, attractiveness, and gender. However, the specific facial characteristics that enable one to identify gender are largely unknown. Research suggests that femininity is a critical component of beauty; however, the most important identifiers of a woman's face are unknown. The objectives of this article were: 1) determine the area of the face most significant in identifying female gender, 2) determine if individuals with gender-confirming surgery of the face are identified as male or female, 3) review the efficacy and safety of a series of feminizing forehead cranioplasties.

STUDY DESIGN

1) Prospective evaluation of computer simulated changes and postoperative patient images, 2) retrospective review of medical records.

METHODS

1) Photographs of men were digitally altered to adjust (a) the forehead (b) the nose/lip, (c) the jaw. Each change a, b, or c is done in isolation in both frontal and profile views. Subjects were shown the three profile and the three frontal photographs and asked to rate which of each set is the most feminine. 2) Photographs of male-to-female (MTF) transgender patients who may have had forehead, midface, or jaw surgery were shown to subjects. Subjects were asked the gender of the person in each picture. 3) Medical records and operative reports of 168 patients who underwent feminizing forehead cranioplasty were evaluated for surgical technique, and complications.

RESULTS

For Experiment 1, in frontal views of all subjects the forehead modification was selected as the most feminine, whereas in no cases was the forehead modification selected as least feminine by a majority of respondents. For the profile view, again the forehead modification was selected as most feminine by respondents for the majority of subjects, but surprisingly, the strength of the association between frontal modification and femininity, while strongly statistically significant, was more evident in the frontal view. For Experiment 2, among transgendered faces shown to viewers, 82% of postoperative forehead modifications were judged as women, 87% of postoperative midface modifications were judged as women, and 85% of postoperative lower faces were judged as women. For section 3, the review of safety and technique in 168 feminizing forehead cranioplasties, there were three basic surgical techniques utilized with only three complications for an overall complication rate of 1.8%.

CONCLUSIONS

Feminization of the forehead through cranioplasty is safe and has a significant impact in determining the gender of the patient. The strong association between femininity and attractiveness can now be more specifically attributed to the upper third of the face and the interplay of the glabellar prominence of the forehead, along with the eyebrow shape and position, and hairline shape and position. These results have strong implications for a paradigm shift in the method of facial analysis used to select aesthetic procedures and illuminates the processes by which femininity and attractiveness are interpreted in faces.

Infant preference for individual women's faces extends to girl prototype faces

Three- to 4-month-old infants reared by female caregivers display a spontaneous preference for individual adult women's over men's faces. Here we report that this preference extends to prototype girl over boy faces. The findings suggest transfer of gender-diagnostic facial information from individual adult to prototype child faces.

Emotion recognition across cultures: the influence of ethnicity on empathic accuracy and physiological linkage

The present study tested whether empathic accuracy and physiological linkage during an emotion recognition task are facilitated by a cultural match between rater and target (cultural advantage model) or unaffected (cultural equivalence model). Participants were 161 college students of African American, Chinese American, European American, or Mexican American ethnicity. To assess empathic accuracy-knowing what another person is feeling-participant's (raters) used a rating dial to provide continuous, real-time ratings of the valence and intensity of emotions being experienced by 4 strangers (targets). Targets were African American, Chinese American, European American, or Mexican American women who had been videotaped having a conversation with their dating partner in a previous study and had rated their own feelings during the interaction. Empathic accuracy was defined as the similarity between ratings of the videotaped interactions obtained from raters and targets. To assess emotional empathy--feeling what another person is feeling--we examined physiological linkage (similarity between raters' and targets' physiology). Our findings for empathic accuracy supported the cultural equivalence model, while those for physiological linkage provided some support for the cultural advantage model.

Anchoring gaze when categorizing faces' sex: evidence from eye-tracking data

Previous research has shown that during recognition of frontal views of faces, the preferred landing positions of eye fixations are either on the nose or the eye region. Can these findings generalize to other facial views and a simpler perceptual task? An eye-tracking experiment investigated categorization of the sex of faces seen in four views. The results revealed a strategy, preferred in all views, which consisted of focusing gaze within an 'infraorbital region' of the face. This region was fixated more in the first than in subsequent fixations. Males anchored gaze lower and more centrally than females.

Gaze behavior in face comparison: the roles of sex, task, and symmetry

Knowing where people look on a face provides an objective insight into the information entering the visual system and into cognitive processes involved in face perception. In the present study, we recorded eye movements of human participants while they compared two faces presented simultaneously. Observers' viewing behavior and performance was examined in two tasks of parametrically varying difficulty, using two types of face stimuli (sex morphs and identity morphs). The frequency, duration, and temporal sequence of fixations on previously defined areas of interest in the faces were analyzed. As was expected, viewing behavior and performance varied with difficulty. Interestingly, observers compared predominantly the inner halves of the face stimuli-a result inconsistent with the general left-hemiface bias reported for single faces. Furthermore, fixation patterns and performance differed between tasks, independently of stimulus type. Moreover, we found differences in male and female participants' viewing behaviors, but only when the sex of the face stimuli was task relevant.

Cultural confusions show that facial expressions are not universal

Central to all human interaction is the mutual understanding of emotions, achieved primarily by a set of biologically rooted social signals evolved for this purpose-facial expressions of emotion. Although facial expressions are widely considered to be the universal language of emotion, some negative facial expressions consistently elicit lower recognition levels among Eastern compared to Western groups (see [4] for a meta-analysis and [5, 6] for review). Here, focusing on the decoding of facial expression signals, we merge behavioral and computational analyses with novel spatiotemporal analyses of eye movements, showing that Eastern observers use a culture-specific decoding strategy that is inadequate to reliably distinguish universal facial expressions of "fear" and "disgust." Rather than distributing their fixations evenly across the face as Westerners do, Eastern observers persistently fixate the eye region. Using a model information sampler, we demonstrate that by persistently fixating the eyes, Eastern observers sample ambiguous information, thus causing significant confusion. Our results question the universality of human facial expressions of emotion, highlighting their true complexity, with critical consequences for cross-cultural communication and globalization.

Familiarity effects on categorization levels of faces and objects

It is well established that faces, in contrast to objects, are categorized as fast or faster at the individual level (e.g., Bill Clinton) than at the basic-level (e.g., human face). This subordinate-shift from basic-level categorization has been considered an outcome of visual expertise with processing faces. However, in the present study we found that, similar to familiar faces, categorization of individually-known familiar towers is also faster at the individual level than at the basic-level in naïve participants. In addition, category-verification of familiar stimuli, at basic and superordinate levels, was slower and less accurate compared to unfamiliar stimuli. Thus, the existence of detailed semantic information, regardless of expertise, can induce a shift in the default level of object categorization from basic to individual level. Moreover, the individually-specific knowledge is not only more easily-retrieved from memory but it might also interfere with accessing more general category information.

Effect of face familiarity on age decision

The present experiment was planned to check whether the extraction of apparent age is affected by face identity (familiarity) or not. According to the traditional view, age estimation should be carried out independently of face identity, because it is one of the visually derived semantic codes (like gender and ethnicity). However, little is known about its underlying mechanisms. Moreover, some recent studies have cast doubt on the parallel thesis regarding facial expression, facial speech, ethnicity, and gender. Given the promising results of a pilot experiment (n=24), 16 Caucasian participants were enrolled in an "age decision" task on morphed faces derived from one old and one young source-face, in the proportion 70:30. The respondents had previously been familiarised with half the source faces by a learning procedure (associating the face, surname, occupation and city of residence of the person displayed), while the remaining half were unfamiliar. The results showed that age decision was affected by face familiarity, at least when the task was perceptually difficult enough. This adds support to the thesis that the identification of identity and the extraction of visually derived semantic codes are not made independently from each other. The status of age, within the visually derived semantic codes, is also discussed.

Simulating the 'other-race' effect with autoassociative neural networks: further evidence in favor of the face-space model

Other-race (OR) faces are less accurately recognized than same-race (SR) faces, but faster classified by race. This phenomenon has often been reported as the 'other-race' effect (ORE). Valentine (1991 Quarterly Journal of Experimental Psychology A: Human Experimental Psychology 43 161-204) proposed a theoretical multidimensional face-space model that explained both of these results, in terms of variations in exemplar density between races. According to this model, SR faces are more widely distributed across the dimensions of the space than OR faces. However, this model does not quantify nor state the dimensions coded within this face space. The aim of the present study was to test the face-space explanation of the ORE with neural network simulations by quantifying its dimensions. We found the predicted density properties of Valentine's framework in the face-projection spaces of the autoassociative memories. This was supported by an interaction for exemplar density between the race of the learned face set and the race of the faces. In addition, the elaborated face representations showed optimal responses for SR but not for OR faces within SR face spaces when explored at the individual level, as gender errors occurred significantly more often in OR than in SR face-space representations. Altogether, our results add further evidence in favor of a statistical exemplar density explanation of the ORE as suggested by Valentine, and question the plausibility of such coding for faces in the framework of recent neuroimaging studies.