Both children and adults scan faces of own and other races differently

Impaired inhibitory control when processing real but not cartoon emotional faces in autistic children: Evidence from an event-related potential study

Impaired socioemotional functioning characterizes autistic children, but does weak inhibition control underlie their socioemotional difficulty? This study addressed this question by examining whether and, if so, how inhibition control is affected by face realism and emotional valence in school-age autistic and neurotypical children. Fifty-two autistic and 52 age-matched neurotypical controls aged 10-12 years completed real and cartoon emotional face Go/Nogo tasks while event-related potentials (ERPs) were recorded. The analyses of inhibition-emotion components (i.e., N2, P3, and LPP) and a face-specific N170 revealed that autistic children elicited greater N2 while inhibiting Nogo trials and greater P3/LPP and late LPP for real but not cartoon emotional faces. Moreover, autistic children exhibited a reduced N170 to real face emotions only. Furthermore, correlation results showed that better behavioral inhibition and emotion recognition in autistic children were associated with a reduced N170. These findings suggest that neural mechanisms of inhibitory control in autistic children are less efficient and more disrupted during real face processing, which may affect their age-appropriate socio-emotional development.

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.

Age Weakens the Other-Race Effect among Han Subjects in Recognizing Own- and Other-Ethnicity Faces

The development and change in the other-race effect (ORE) in different age groups have always been a focus of researchers. Previous studies have mainly focused on the influence of maturity of life (from infancy to early adulthood) on the ORE, while few researchers have explored the ORE in older people. Therefore, this study used behavioral and eye movement techniques to explore the influence of age on the ORE and the visual scanning pattern of Han subjects recognizing own- and other-ethnicity faces. All participants were asked to complete a study-recognition task for faces, and the behavioral results showed that the ORE of elderly Han subjects was significantly lower than that of young Han subjects. The results of eye movement showed that there were significant differences in the visual scanning pattern of young subjects in recognizing the faces of individuals of their own ethnicity and other ethnicities, which were mainly reflected in the differences in looking at the nose and mouth, while the differences were reduced in the elderly subjects. The elderly subjects used similar scanning patterns to recognize the own- and other-ethnicity faces. This indicates that as age increases, the ORE of older people in recognizing faces of those from different ethnic groups becomes weaker, and elderly subjects have more similar visual scanning patterns in recognizing faces of their own and other ethnicities.

Attention mechanisms and emotion judgment for Korean and American emotional faces: an eye movement study

Introduction

This study investigates attention mechanisms and the accuracy of emotion judgment among South Korean children by employing Korean and American faces in conjunction with eye-tracking technology.

Methods

A total of 42 participants were individually presented with photos featuring either Korean or American children, and their task was to judge the emotions conveyed through the facial expressions in each photo. The participants' eye movements during picture viewing were meticulously observed using an eye tracker.

Results

The analysis of the emotion judgment task outcomes revealed that the accuracy scores for discerning emotions of joy, sadness, and anger in Korean emotional faces were found to be significantly higher than those for American children. Conversely, no significant difference in accuracy scores was observed for the recognition of fear emotion between Korean and American faces. Notably, the study also uncovered distinct patterns of fixation duration among children, depending on whether they were viewing Korean or American faces. These patterns predominantly manifested in the three main facial areas of interest, namely the eyes, nose, and mouth.

Discussion

The observed phenomena can be best understood within the framework of the "other-race effect." Consequently, this prototype formation leads to heightened accuracy in recognizing and interpreting emotional expressions exhibited by faces belonging to the same racial group. The present study contributes to a deeper understanding of how attention mechanisms and other-race effects impact emotion judgment among South Korean children. The utilization of eye-tracking technology enhances the validity and precision of our findings, providing valuable insights for both theoretical models of face processing and practical applications in various fields such as psychology, education, and intercultural communication.

Face race and sex impact visual fixation strategies for upright and inverted faces in 3- to 6-year-old children

Everyday face experience tends to be biased, such that infants and young children interact more often with own-race and female faces leading to differential processing of faces within these groups relative to others. In the present study, visual fixation strategies were recorded using eye tracking to determine the extent to which face race and sex/gender impact a key index of face processing in 3- to 6-year-old children (n = 47). Children viewed male and female upright and inverted White and Asian faces while visual fixations were recorded. Face orientation was found to have robust effects on children's visual fixations, such that children exhibited shorter first fixation and average fixation durations and a greater number of fixations for inverted compared to upright face trials. First fixations to the eye region were also greater for upright compared to inverted faces. Fewer fixations and longer duration fixations were found for trials with male compared to female faces and for upright compared to inverted unfamiliar-race faces, but not familiar-race faces. These findings demonstrate evidence of differential fixation strategies toward different types of faces in 3- to 6-year-old children, illustrating the importance of experience in the development of visual attention to faces.

Disrupted visual input unveils the computational details of artificial neural networks for face perception

Background

Convolutional Neural Network (DCNN), with its great performance, has attracted attention of researchers from many disciplines. The studies of the DCNN and that of biological neural systems have inspired each other reciprocally. The brain-inspired neural networks not only achieve great performance but also serve as a computational model of biological neural systems.

Methods

Here in this study, we trained and tested several typical DCNNs (AlexNet, VGG11, VGG13, VGG16, DenseNet, MobileNet, and EfficientNet) with a face ethnicity categorization task for experiment 1, and an emotion categorization task for experiment 2. We measured the performance of DCNNs by testing them with original and lossy visual inputs (various kinds of image occlusion) and compared their performance with human participants. Moreover, the class activation map (CAM) method allowed us to visualize the foci of the "attention" of these DCNNs.

Results

The results suggested that the VGG13 performed the best: Its performance closely resembled human participants in terms of psychophysics measurements, it utilized similar areas of visual inputs as humans, and it had the most consistent performance with inputs having various kinds of impairments.

Discussion

In general, we examined the processing mechanism of DCNNs using a new paradigm and found that VGG13 might be the most human-like DCNN in this task. This study also highlighted a possible paradigm to study and develop DCNNs using human perception as a benchmark.

Own Race Eye-Gaze Bias for All Emotional Faces but Accuracy Bias Only for Sad Expressions

Own race faces tend to be recognized more accurately than those of other less familiar races, however, findings to date have been inconclusive. The present study aimed to determine whether Chinese exhibit different recognition accuracy and eye gaze patterns for Asian (own-race) and White (other-race) facial expressions (neutral, happiness, sadness, anger, disgust, fear). A total of 89 healthy Chinese adults viewed Asian and White facial expressions while undergoing eye-tracking and were subsequently required to identify expressions and rate their intensity and effect on arousal. Results revealed that subjects recognized sad expressions in Asian faces better than in White ones. On the other hand, recognition accuracy was higher for White neutral, happy, fearful, and disgusted expressions although this may have been due to subjects more often misclassifying these Asian expressions as sadness. Moreover, subjects viewed the eyes of emotional expressions longer in Asian compared to White faces and the nose of sad ones, especially during the late phase of presentation, whereas pupil sizes, indicative of cognitive load and arousal, were smaller. Eye-gaze patterns were not, however, associated with recognition accuracy. Overall, findings demonstrate an own-race bias in Chinese for identifying sad expressions and more generally across emotional expressions in terms of viewing the eye region of emotional faces for longer and with reduced pupil size. Interestingly, subjects were significantly more likely to miss-identify Asian faces as sad resulting in an apparent other-race bias for recognizing neutral, happy, fearful, and disgusted expressions.

Perceiving ingroup and outgroup faces within and across nations

The human face is arguably the most important of all social stimuli because it provides so much valuable information about others. Therefore, one critical factor for successful social communication is the ability to process faces. In general, a wide body of social cognitive research has demonstrated that perceivers are better at extracting information from their own-race compared to other-race faces and that these differences can be a barrier to positive cross-race relationships. The primary objective of the present paper was to provide an overview of how people process faces in diverse contexts, focusing on racial ingroup and outgroup members within one nation and across nations. To achieve this goal, we first broadly describe social cognitive research on categorization processes related to ingroups vs. outgroups. Next, we briefly examine two prominent mechanisms (experience and motivation) that have been used to explain differences in recognizing facial identities and identifying emotions when processing ingroup and outgroup racial faces within nations. Then, we explore research in this domain across nations and cultural explanations, such as norms and practices, that supplement the two proposed mechanisms. Finally, we propose future cross-cultural research that has the potential to help us better understand the role of these key mechanisms in processing ingroup and outgroup faces.

Infants' visual exploration strategies for adult and child faces

By the end of the first year of life, infants' discrimination abilities tune to frequently experienced face groups. Little is known about the exploration strategies adopted to efficiently discriminate frequent, familiar face types. The present eye-tracking study examined the distribution of visual fixations produced by 10-month-old and 4-month-old singletons while learning adult (i.e., familiar) and child (i.e., unfamiliar) White faces. Infants were tested in an infant-controlled visual habituation task, in which post-habituation preference measured successful discrimination. Results confirmed earlier evidence that, without sibling experience, 10-month-olds discriminate only among adult faces. Analyses of gaze movements during habituation showed that infants' fixations were centered in the upper part of the stimuli. The mouth was sampled longer in adult faces than in child faces, while the child eyes were sampled longer and more frequently than the adult eyes. At 10 months, but not at 4 months, global measures of scanning behavior on the whole face also varied according to face age, as the spatiotemporal distribution of scan paths showed larger within- and between-participants similarity for adult faces than for child faces. Results are discussed with reference to the perceptual narrowing literature, and the influence of age-appropriate developmental tasks on infants' face processing abilities.

Human face and gaze perception is highly context specific and involves bottom-up and top-down neural processing

This review summarizes human perception and processing of face and gaze signals. Face and gaze signals are important means of non-verbal social communication. The review highlights that: (1) some evidence is available suggesting that the perception and processing of facial information starts in the prenatal period; (2) the perception and processing of face identity, expression and gaze direction is highly context specific, the effect of race and culture being a case in point. Culture affects by means of experiential shaping and social categorization the way in which information on face and gaze is collected and perceived; (3) face and gaze processing occurs in the so-called 'social brain'. Accumulating evidence suggests that the processing of facial identity, facial emotional expression and gaze involves two parallel and interacting pathways: a fast and crude subcortical route and a slower cortical pathway. The flow of information is bi-directional and includes bottom-up and top-down processing. The cortical networks particularly include the fusiform gyrus, superior temporal sulcus (STS), intraparietal sulcus, temporoparietal junction and medial prefrontal cortex.

(Eye-) Tracking the Other-Race Effect: Comparison of Eye Movements During Encoding and Recognition of Ingroup Faces With Proximal and Distant Outgroup Faces

People experience difficulties recognizing faces of ethnic outgroups, known as the other-race effect. The present eye-tracking study investigates if this effect is related to differences in visual attention to ingroup and outgroup faces. We measured gaze fixations to specific facial features and overall eye-movement activity level during an old/new recognition task comparing ingroup faces with proximal and distal ethnic outgroup faces. Recognition was best for ingroup faces and decreased gradually for proximal and distal outgroup faces. Participants attended more to the eyes of ingroup faces than outgroup faces, but this effect was unrelated to recognition performance. Ingroup-outgroup differences in eye-movement activity level did not emerge during the study phase, but during the recognition phase, with ingroup-outgroup differences varying as a function of recognition accuracy and old/new effects. Overall, ingroup-outgroup effects on recognition performance and eye movements were more pronounced for recognition of new items, emphasizing the role of retrieval processes.

Infant Eye Gaze While Viewing Dynamic Faces

Research using eye tracking methods has revealed that when viewing faces, between 6 to 10 months of age, infants begin to shift visual attention from the eye region to the mouth region. Moreover, this shift varies with stimulus characteristics and infants’ experience with faces and languages. The current study examined the eye movements of a racially diverse sample of 98 infants between 7.5 and 10.5 months of age as they viewed movies of White and Asian American women reciting a nursery rhyme (the auditory component of the movies was replaced with music to eliminate the influence of the speech on infants’ looking behavior). Using an analytic approach inspired by the multiverse analysis approach, several measures from infants’ eye gaze were examined to identify patterns that were robust across different analyses. Although in general infants preferred the lower regions of the faces, i.e., the region containing the mouth, this preference depended on the stimulus characteristics and was stronger for infants whose typical experience included faces of more races and for infants who were exposed to multiple languages. These results show how we can leverage the richness of eye tracking data with infants to add to our understanding of the factors that influence infants’ visual exploration of faces.

Predominance of eyes and surface information for face race categorization

Faces can be categorized in various ways, for example as male or female or as belonging to a specific biogeographic ancestry (race). Here we tested the importance of the main facial features for race perception. We exchanged inner facial features (eyes, mouth or nose), face contour (everything but those) or texture (surface information) between Asian and Caucasian faces. Features were exchanged one at a time, creating for each Asian/Caucasian face pair ten facial variations of the original face pair. German and Korean participants performed a race classification task on all faces presented in random order. The results show that eyes and texture are major determinants of perceived biogeographic ancestry for both groups of participants and for both face types. Inserting these features in a face of another race changed its perceived biogeographic ancestry. Contour, nose and mouth, in that order, had decreasing and much weaker influence on race perception for both participant groups. Exchanging those features did not induce a change of perceived biogeographic ancestry. In our study, all manipulated features were imbedded in natural looking faces, which were shown in an off-frontal view. Our findings confirm and extend previous studies investigating the importance of various facial features for race perception.

Age of smile: a cross-cultural replication report of Ganel and Goodale (2018)

Smiling is believed to make people look younger. Ganel and Goodale (Psychon Bull Rev 25(6):612–616, 10.3758/s13423-017-1306-8, 2018) proposed that this belief is a misconception rooted in popular media, based on their findings that people actually perceive smiling faces as older. However, they did not clarify whether this misconception can be generalized across cultures. We tested the cross-cultural validity of Ganel and Goodale’s findings by collecting data from Japanese and Swedish participants. Specifically, we aimed to replicate Ganel and Goodale’s study using segregated sets of Japanese and Swedish facial stimuli, and including Japanese and Swedish participants in groups asked to estimate the age of either Japanese or Swedish faces (two groups of participants × two groups of stimuli; four groups total). Our multiverse analytical approach consistently showed that the participants evaluated smiling faces as older in direct evaluations, regardless of the facial stimuli culture or their nationality, although they believed that smiling makes people look younger. Further, we hypothesized that the effect of wrinkles around the eyes on the estimation of age would vary with the stimulus culture, based on previous studies. However, we found no differences in age estimates by stimulus culture in the present study. Our results showed that we successfully replicated Ganel and Goodale (2018) in a cross-cultural context. Our study thus clarified that the belief that smiling makes people look younger is a common cultural misconception.

Effects of Baby Schema and Mere Exposure on Explicit and Implicit Face Processing

In an increasingly multicultural society, the way people perceive individuals from the same vs different ethnic groups greatly affects their own and societal well-being. Two psychological effects that influence these perceptions are the Mere-Exposure Effect (MRE), wherein familiarity with certain objects or persons suffices for people to develop a preference for them, and the Baby Schema (BS), a set of specific facial features that evokes caregiving behaviors and an affective orientation in adults. In the present study, we aimed to investigate whether these two effects play a role in implicit physiological responses to babies vs. adults faces belonging to participants in-group vs. out-group. In study 1, the pupillary diameter of 62 Caucasian participants (M = 31; F = 31) who observed adult and infant faces of different ethnic groups (Caucasian, Chinese) was measured. In study 2, brain waves of 38 Caucasian participants (M = 19; F = 19), who observed the same set of faces, were recorded using EEG. In both studies, adults explicit preferences (i.e., attitudes) toward faces were assessed using questionnaires. In Study 1, females showed greater attention to infant than adult faces (BS effect) in both pupils, regardless of the ethnic group of the face. By contrast, males attended to infant more than adult faces for out-group faces only (BS effect). In Study 2, greater left posterior-parietal alpha activation toward out-group compared to in-group adult faces was found in males (MRE). Participants with a low BS effect toward in-group baby faces exhibited greater left posterior alpha activation to out-group than in-group baby faces (MRE). These findings reveal how different levels of sensitivity to in-group infants may moderate perceptions of both in-group and out-group baby faces. Questionnaire measures on attitudes showed that males and females preferred in-group to out-group adult faces (MRE). Participants in Study 2 also reported a greater preference for infants than adults faces (BS effect). These findings explicate the roles of gender and the Baby Schema effect in moderating implicit processing of in-group and out-group faces, despite their lack in moderating explicit reports. Contradictory findings at the implicit (physiological) and explicit (self-report) levels suggest that differential processing of faces may occur at a non-conscious level.

Relations between scanning and recognition of own- and other-race faces in 6- and 9-month-old infants

Infants typically see more own-race faces than other-race faces. Existing evidence shows that this difference in face race experience has profound consequences for face processing: as early as 6 months of age, infants scan own- and other-race faces differently and display superior recognition for own- relative to other-race faces. However, it is unclear whether scanning of own-race faces is related to the own-race recognition advantage in infants. To bridge this gap in the literature, the current study used eye tracking to investigate the relation between own-race face scanning and recognition in 6- and 9-month-old Asian infants (N = 82). The infants were familiarized with dynamic own- and other-race faces, and then their face recognition was tested with static face images. Both age groups recognized own- but not other-race faces. Also, regardless of race, the more infants scanned the eyes of the novel versus familiar faces at test, the better their face-recognition performance. In addition, both 6- and 9-month-olds fixated significantly longer on the nose of own-race faces, and greater fixation on the nose during test trials correlated positively with individual novelty preference scores in the own- but not other-race condition. The results suggest that some aspects of the relation between recognition and scanning are independent of differential experience with face race, whereas other aspects are affected by such experience. More broadly, the findings imply that scanning and recognition may become linked during infancy at least in part through the influence of perceptual experience.

Does the implicit models of leadership influence the scanning of other-race faces in adults?

The current study aims to identify the relationships between implicit leadership theoretical (ILT) prototypes / anti-prototype and five facial features (i.e., nasion, upper nose, lower nose, and upper lip) of a leader from a different race than respondents. A sample of 81 Asian respondents viewed a 30-second video of a Caucasian female who in a non-engaging manner talked about her career achievements. As participants watch the video, their eye movements were recorded via an eye tracking devise. While previous research has identified that ILT influences perceptional and attitudinal ratings of leaders, the current study extends these findings by confirming the impact of ILT on the gaze patterns of other race participants, who appear to adopt system one type thinking. This study advances our understanding in how cognitive categories or schemas influence the physicality of individuals (i.e., eye gaze or movements). Finally, this study confirms that individual ILT factors have a relationship with the eye movements of participants and suggests future research directions.

Face race processing and racial bias in early development: A perceptual-social linkage

Infants have asymmetrical exposure to different types of faces (e.g., more human than other-species, more female than male, and more own-race than other-race). What are the developmental consequences of such experiential asymmetry? Here we review recent advances in research on the development of cross-race face processing. The evidence suggests that greater exposure to own- than other-race faces in infancy leads to developmentally early perceptual differences in visual preference, recognition, category formation, and scanning of own- and other-race faces. Further, such perceptual differences in infancy may be associated with the emergence of implicit racial bias, consistent with a Perceptual-Social Linkage Hypothesis. Current and future work derived from this hypothesis may lay an important empirical foundation for the development of intervention programs to combat the early occurrence of implicit racial bias.

Scanning of own- versus other-race faces in infants from racially diverse or homogenous communities

We examined the role of community face experience on 6- and 8-month-old Caucasian infants' scanning of own- and other-race face scanning. We measured infants' proportional fixation time and scan path amplitudes as indices of face processing. Proportional fixation time to informationally rich face regions varied as a function of age and face race for infants living in a racially homogeneous community, whereas scan path amplitudes varied as a function of age and face race for infants living in a racially diverse community. In both communities 6-month-old infants did not show different responding to own- and other-race faces, whereas 8-month-old infants responded differently to own- and other-race faces. However, 8-month-old infants from the two communities showed different patterns of cross-race face scanning. Therefore, experience in the community beyond the home appears to contribute to the development of differential scanning of own- versus other-race faces between 6 and 8 months of age.

Plasticity may change inputs as well as processes, structures, and responses

Significant work has documented neuroplasticity in development, demonstrating that developmental pathways are shaped by experience. Plasticity is often discussed in terms of the results of differences in input; differences in brain structures, processes, or responses reflect differences in experience. In this paper, I discuss how developmental plasticity also effectively changes input into the system. That is, structures and processes change in response to input, and those changed structures and processes influence future inputs. For example, plasticity may change the pattern of eye movements to a stimulus, thereby changing which part of the scene becomes the input. Thus, plasticity is not only seen in the structures and processes that result from differences in experience, but also is seen in the changes in the input as those structures and processes adapt. The systematic study of the nature of experience, and how differences in experience shape learning, can contribute to our understanding of neuroplasticity in general.

Infant attention to same- and other-race faces

We recorded visual attention to same- and other-race faces in Hispanic and White 11-month-old infants, an age at which face processing is presumably biased by an own-race recognition advantage. Infants viewed pairs of faces differing in race or ethnicity as their eye movements were recorded. We discovered consistently greater attention to Black over Hispanic faces, to Black faces over White faces, and to Hispanic over White faces. Inversion of face stimuli, and infant ethnicity, had little effect on performance. Infants' social environments, however, differed sharply according to ethnicity: Hispanic infants are almost exclusively exposed to Hispanic family members, and White infants to White family members. Moreover, Hispanic infants inhabit communities that are more racially and ethnically diverse. These results imply that race-based visual attention in infancy is closely aligned with the larger society's racial and ethnic composition, as opposed to race-based recognition, which is more closely aligned with infants' immediate social environments.

An Own-Age Bias in Recognizing Faces with Horizontal Information

Horizontal information, as a result of a selective filtering process, is essential in younger adults’ (YA) ability to recognize human faces. Obermeyer et al. (2012) recently reported impaired recognition of faces with horizontal information in older adults (OA) suggesting age-variant processing. Two yet unconsidered factors (stimulus age and exposure duration) that may have influenced previous results, were investigated in this study. Forty-seven YA (18–35 years) and 49 OA (62–83 years) were tested in a 2 × 2 × 2 × 2 mixed design with the between-subjects factors age group (YA vs. OA) and stimulus age (young faces vs. older faces) and the within-subjects factors filter [filtered (HF) faces vs. unfiltered faces (UF)] and exposure duration (0.8 s vs. 8 s). Subjects were presented morph videos between pairs of faces: a starting face gradually merged into either the previously encoded target face or a control face. As expected, results showed an increase in recognition sensitivity (d′) with longer exposure duration in YA with both younger and older HF faces. OA, however, were unable to recognize filtered young faces not even with increased exposure duration. Furthermore, only elderly participants showed more accurate recognition with faces of their own age relative to other-age faces (own-age bias, OAB). For YA no OAB was observed. Filtered face recognition was significantly correlated with unfiltered recognition in YA but not in OA. It is concluded, that processing of horizontal information changes at a higher age. Presenting filtered or unfiltered faces both targets convergent face-specific processing only in YA but not in OA.

Development of Effective Connectivity during Own- and Other-Race Face Processing: A Granger Causality Analysis

Numerous developmental studies have suggested that other-race effect (ORE) in face recognition emerges as early as in infancy and develops steadily throughout childhood. However, there is very limited research on the neural mechanisms underlying this developmental ORE. The present study used Granger causality analysis (GCA) to examine the development of children's cortical networks in processing own- and other-race faces. Children were between 3 and 13 years. An old-new paradigm was used to assess their own- and other-race face recognition with ETG-4000 (Hitachi Medical Co., Japan) acquiring functional near infrared spectroscopy (fNIRS) data. After preprocessing, for each participant and under each face condition, we obtained the causal map by calculating the weights of causal relations between the time courses of [oxy-Hb] of each pair of channels using GCA. To investigate further the differential causal connectivity for own-race faces and other-race faces at the group level, a repeated measure analysis of variance (ANOVA) was performed on the GCA weights for each pair of channels with the face race task (own-race face vs. other-race face) as the within-subject variable and the age as a between-subject factor (continuous variable). We found an age-related increase in functional connectivity, paralleling a similar age-related improvement in behavioral face processing ability. More importantly, we found that the significant differences in neural functional connectivity between the recognition of own-race faces and that of other-race faces were modulated by age. Thus, like the behavioral ORE, the neural ORE emerges early and undergoes a protracted developmental course.

An adult face bias in infants that is modulated by face race

The visual preferences of infants for adult versus infant faces were investigated. Caucasian 3.5- and 6-month-olds were presented with Caucasian adult versus infant face pairs and Asian adult versus infant face pairs, in both upright and inverted orientations. Both age groups showed a visual preference for upright adult over infant faces when the faces were Caucasian, but not when they were Asian. The preference is unlikely to have arisen because of low-level perceptual features because: (1) no preference was observed for the inverted stimuli, (2) no differences were observed in adult similarity ratings of the upright infant-adult face pairs from the two races, and (3) no differences between the infant and adult faces were observed across races in an image-based analysis of salience. The findings are discussed in terms of the social attributes of faces that are learned from experience and what this implies for developmental accounts of a recognition advantage for adult faces in particular and models of face processing more generally.

Differences in Looking at Own- and Other-Race Faces Are Subtle and Analysis-Dependent: An Account of Discrepant Reports

The Other-Race Effect (ORE) is the robust and well-established finding that people are generally poorer at facial recognition of individuals of another race than of their own race. Over the past four decades, much research has focused on the ORE because understanding this phenomenon is expected to elucidate fundamental face processing mechanisms and the influence of experience on such mechanisms. Several recent studies of the ORE in which the eye-movements of participants viewing own- and other-race faces were tracked have, however, reported highly conflicting results regarding the presence or absence of differential patterns of eye-movements to own- versus other-race faces. This discrepancy, of course, leads to conflicting theoretical interpretations of the perceptual basis for the ORE. Here we investigate fixation patterns to own- versus other-race (African and Chinese) faces for Caucasian participants using different analysis methods. While we detect statistically significant, though subtle, differences in fixation pattern using an Area of Interest (AOI) approach, we fail to detect significant differences when applying a spatial density map approach. Though there were no significant differences in the spatial density maps, the qualitative patterns matched the results from the AOI analyses reflecting how, in certain contexts, Area of Interest (AOI) analyses can be more sensitive in detecting the differential fixation patterns than spatial density analyses, due to spatial pooling of data with AOIs. AOI analyses, however, also come with the limitation of requiring a priori specification. These findings provide evidence that the conflicting reports in the prior literature may be at least partially accounted for by the differences in the statistical sensitivity associated with the different analysis methods employed across studies. Overall, our results suggest that detection of differences in eye-movement patterns can be analysis-dependent and rests on the assumptions inherent in the given analysis.

Visual scanning behavior is related to recognition performance for own- and other-age faces

It is well-established that our recognition ability is enhanced for faces belonging to familiar categories, such as own-race faces and own-age faces. Recent evidence suggests that, for race, the recognition bias is also accompanied by different visual scanning strategies for own- compared to other-race faces. Here, we tested the hypothesis that these differences in visual scanning patterns extend also to the comparison between own and other-age faces and contribute to the own-age recognition advantage. Participants (young adults with limited experience with infants) were tested in an old/new recognition memory task where they encoded and subsequently recognized a series of adult and infant faces while their eye movements were recorded. Consistent with findings on the other-race bias, we found evidence of an own-age bias in recognition which was accompanied by differential scanning patterns, and consequently differential encoding strategies, for own-compared to other-age faces. Gaze patterns for own-age faces involved a more dynamic sampling of the internal features and longer viewing time on the eye region compared to the other regions of the face. This latter strategy was extensively employed during learning (vs. recognition) and was positively correlated to discriminability. These results suggest that deeply encoding the eye region is functional for recognition and that the own-age bias is evident not only in differential recognition performance, but also in the employment of different sampling strategies found to be effective for accurate recognition.

Differential emotion attribution to neutral faces of own and other races

Past research has demonstrated differential recognition of emotion on faces of different races. This paper reports the first study to explore differential emotion attribution to neutral faces of different races. Chinese and Caucasian adults viewed a series of Chinese and Caucasian neutral faces and judged their outward facial expression: neutral, positive, or negative. The results showed that both Chinese and Caucasian viewers perceived more Chinese faces than Caucasian faces as neutral. Nevertheless, Chinese viewers attributed positive emotion to Caucasian faces more than to Chinese faces, whereas Caucasian viewers attributed negative emotion to Caucasian faces more than to Chinese faces. Moreover, Chinese viewers attributed negative and neutral emotion to the faces of both races without significant difference in frequency, whereas Caucasian viewers mostly attributed neutral emotion to the faces. These differences between Chinese and Caucasian viewers may be due to differential visual experience, culture, racial stereotype, or expectation of the experiment. We also used eye tracking among the Chinese participants to explore the relationship between face-processing strategy and emotion attribution to neutral faces. The results showed that the interaction between emotion attribution and face race was significant on face-processing strategy, such as fixation proportion on eyes and saccade amplitude. Additionally, pupil size during processing Caucasian faces was larger than during processing Chinese faces.

Narrowing in categorical responding to other-race face classes by infants

Infants can form object categories based on perceptual cues, but their ability to form categories based on differential experience is less clear. Here we examined whether infants filter through perceptual differences among faces from different other-race classes and represent them as a single other-race class different only from own-race faces. We used a familiarization/novelty-preference procedure to investigate category formation for two other-race face classes (Black vs. Asian) by White 6- and 9-month-olds. The data indicated that while White 6-month-olds categorically represented the distinction between Black and Asian faces, White 9-month-olds formed a broad other-race category inclusive of Black and Asian faces, but exclusive of own-race White faces. The findings provide evidence that narrowing can occur for mental processes other than discrimination: category formation is also affected. The results suggest that frequency of experience with own-race versus other-race classes of faces may propel infants to contrast own-race faces with other-race faces, but not different classes of other-race faces with each other.

Do individuals with autism spectrum disorder process own- and other-race faces differently?

Individuals with autism spectrum disorder (ASD) process human faces in atypical ways according to previous literature. We investigated whether individuals with ASD can process face race information and respond to own- and other-race faces differentially. Chinese individuals with ASD (n=24), typically developing (TD) individuals (n=28), and individuals with intellectual disabilities (ID, n=26) were asked to recognize Chinese and Caucasian faces in an old-new face paradigm using eye tracking. In terms of recognition, the ASD and ID groups did not perform differently and displayed superior own-race recognition compared with other-race faces; TD participants displayed similar recognition of the two types of faces. In terms of eye tracking, the TD, ASD, and ID groups displayed more looking on the eyes and less looking on the nose and mouth of Caucasian faces relative to Chinese faces. Overall, individuals with ASD manifested a behavioral other-race effect and displayed the same type of cross-racial differentiation in face scanning observed in TD individuals. The findings suggest that as is the case with TD individuals, face processing of individuals with ASD is influenced by differences in visual experience with different face categories.

Visual scanning and recognition of Chinese, Caucasian, and racially ambiguous faces: contributions from bottom-up facial physiognomic information and top-down knowledge of racial categories

Recent studies have shown that participants use different eye movement strategies when scanning own- and other-race faces. However, it is unclear (1) whether this effect is related to face recognition performance, and (2) to what extent this effect is influenced by top-down or bottom-up facial information. In the present study, Chinese participants performed a face recognition task with Chinese, Caucasian, and racially ambiguous faces. For the racially ambiguous faces, we led participants to believe that they were viewing either own-race Chinese faces or other-race Caucasian faces. Results showed that (1) Chinese participants scanned the nose of the true Chinese faces more than that of the true Caucasian faces, whereas they scanned the eyes of the Caucasian faces more than those of the Chinese faces; (2) they scanned the eyes, nose, and mouth equally for the ambiguous faces in the Chinese condition compared with those in the Caucasian condition; (3) when recognizing the true Chinese target faces, but not the true target Caucasian faces, the greater the fixation proportion on the nose, the faster the participants correctly recognized these faces. The same was true when racially ambiguous face stimuli were thought to be Chinese faces. These results provide the first evidence to show that (1) visual scanning patterns of faces are related to own-race face recognition response time, and (2) it is bottom-up facial physiognomic information that mainly contributes to face scanning. However, top-down knowledge of racial categories can influence the relationship between face scanning patterns and recognition response time.