Infants' top-down perceptual modulation is specific to own-race faces

Recent studies have revealed the influence of higher-level cognitive systems in modulating perceptual processing (top-down perceptual modulation) in infancy. However, more research is needed to understand how top-down processes in infant perception contribute to early perceptual development. To this end, this study examined infants' top-down perception of own- and other-race faces to reveal whether top-down modulation is linked to the emergence of perceptual specialization. Infants first learned an association between a sound and faces, with the race of the faces manipulated between groups (own race vs. other race). We then tested infants' face perception across various levels of perceptual difficulty (manipulated by presentation duration) and indexed top-down perception by the change in perception when infants heard the sound previously associated with the face (predictive sound) versus an irrelevant sound. Infants exhibited top-down face perception for own-race faces (Experiment 1). However, we present new evidence that infants did not show evidence of top-down modulation for other-race faces (Experiment 2), suggesting an experience-based specificity of this capacity with more effective top-down modulation in familiar perceptual contexts. In addition, we ruled out the possibility that this face race effect was due to differences in infants' associative learning of the sound and faces between the two groups. This work has important implications for understanding the mechanisms supporting perceptual development and how they relate to top-down perception in infancy.

The other-race effect in facial expression processing: Behavioral and ERP evidence from a balanced cross-cultural study in women

Although evidence for cultural variants in facial expression decoding is accumulating, the other-race effect in facial expression processing and its neural correlates are still unclear. We investigated this question with a fully balanced design, in which a group of East Asian and a group of European Caucasian women categorized pictures of sad, happy, angry, and neutral facial expressions posed by individuals of their own-race and the other-race. Results revealed a disadvantage in categorizing expressions of anger in other-race faces in both samples, and for sad expressions in the European sample only. Partially consistent, East Asian participants showed longer latency of the N170 component in the event-related potential (ERP) and European Caucasian participants showed larger N170 amplitudes to other-race faces. The late positive complex in the ERP was less distinguishable among other-race facial expressions. Therefore, the present study observed an other-race effect in early and late stages of face processing, reflecting less efficient structural encoding and less elaborate processing for other-race than own-race faces.

How White American Children Develop Racial Biases in Emotion Reasoning

For decades, affective scientists have examined how adults and children reason about others' emotions. Yet, our knowledge is limited regarding how emotion reasoning is impacted by race-that is, how individuals reason about emotions displayed by people of other racial groups. In this review, we examine the developmental origins of racial biases in emotion reasoning, focusing on how White Americans reason about emotions displayed by Black faces/people. We highlight how racial biases in emotion reasoning, which emerge as early as infancy, likely contribute to miscommunications, inaccurate social perceptions, and negative interracial interactions across the lifespan. We conclude by discussing promising interventions to reduce these biases as well as future research directions, highlighting how affective scientists can decenter Whiteness in their research designs. Together, this review highlights how emotion reasoning is a potentially affective component of racial bias among White Americans.

The effect of implicit racial bias on recognition of other-race faces

Previous research has established a possible link between recognition performance, individuation experience, and implicit racial bias of other-race faces. However, it remains unclear how implicit racial bias might influence other-race face processing in observers with relatively extensive experience with the other race. Here we examined how recognition of other-race faces might be modulated by observers’ implicit racial bias, in addition to the effects of experience and face recognition ability. Caucasian participants in a culturally diverse city completed a memory task for Asian and Caucasian faces, an implicit association test, a questionnaire assessing experience with Asians and Caucasians, and a face recognition ability test. As expected, recognition performance for Asian faces was positively predicted by increased face recognition ability, and experience with Asians. More importantly, it was also negatively predicted by increased positive bias towards Asians, which was modulated by an interaction between face recognition ability and implicit bias, with the effect of implicit bias observed predominantly in observers with high face recognition ability. Moreover, the positions of the first two fixations when participants learned the other-race faces were affected by different factors, with the first fixation modulated by the effect of experience and the second fixation modulated by the interaction between implicit bias and face recognition ability. Taken together, these findings suggest the complexity in understanding the perceptual and socio-cognitive influences on the other-race effect, and that observers with high face recognition ability may more likely evaluate racial features involuntarily when recognizing other-race faces.

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.

Similar use of shape and texture cues for own- and other-race faces during face learning and recognition

Although the other-race effect (ORE; superior recognition of own- relative to other-race faces) is well established, the mechanisms underlying it are not well understood. We examined whether the ORE is attributable to differential use of shape and texture cues for own- vs. other-race faces. Shape cues are particularly important for detecting that an own-race face is unfamiliar, whereas texture cues are more important for recognizing familiar and newly learned own-race faces. We compared the influence of shape and texture cues on Caucasian participants' recognition of Caucasian and East Asian faces using two complementary approaches. In Experiment 1, participants studied veridical, shape-caricatured, or texture-caricatured faces and then were asked to recognize them in an old/new recognition task. In Experiment 2, all study faces were veridical and we independently removed the diagnosticity of shape (or texture) cues in the test phase by replacing original shape (or texture) with average shape (or texture). Despite an overall own-race advantage, participants' use of shape and texture cues was comparable for own- and other-race faces. These results suggest that the other-race effect is not attributable to qualitative differences in the use of shape and texture cues.

Facial expressions of anger improve neural correlates of memory retrieval but not encoding of only same-race faces

The other-race effect is the phenomenon that people are better able to recognize and remember faces of their same race. Angry faces have been shown to facilitate processes that promote face recognition as reflected in the proportion of remembered faces after study. The other-race effect may be diminished when other-race faces display negative expressions, but no event-related potential studies have examined whether this improvement in other-race face recognition occurs during facial encoding or recognition. The current study used the old-new recognition task to examine whether anger reduces the other-race effect by improving face memory for other-race faces in comparison to neutral faces and whether this improvement would be reflected during encoding or retrieval. Caucasian and African American faces were rated as angry or neutral by a separate pool of Caucasian participants. Caucasian and African/African American participants in the old-new task studied the faces rated as most angry or neutral and later identified them among distractors in the test phase. The Dm, FN400, and parietal old-new effect were recorded during the study and test phase for Caucasian participants. Anger did not improve other-race face memory in behavior for either race of participants. For Caucasian participants, activation increased during retrieval of previously studied angry Caucasian faces, which indicates more detailed memory retrieval of same-race as compared to other-race angry faces. This is evidence that experience with same-race faces and not stereotypes of other-race faces influences the other-race effect during memory retrieval.

Reorganization in the representation of face-race categories from 6 to 9 months of age: Behavioral and computational evidence

Prior research has reported developmental change in how infants represent categories of other-race faces (Developmental Science 19 (2016) 362-371). In particular, Caucasian 6-month-olds were shown to represent African versus Asian face categories, whereas Caucasian 9 month-olds represented different classes of other-race faces in one category, inclusive of African and Asian faces but exclusive of Caucasian faces. The current investigation sought to provide stronger evidence that is convergent with these findings by asking whether infants will generalize looking-time responsiveness from one to another other-race category. In Experiment 1, an experimental group of Caucasian 6-month-olds was familiarized with African (or Asian) faces and then given a novel category preference test with an Asian (or African) face versus a Caucasian face, while a control group of Caucasian 6-month-olds viewed the test faces without prior familiarization. Infants in the experimental group divided attention between the test faces and infants in the control group did not manifest a spontaneous preference. Experiment 2 used the same procedure, but was conducted with Caucasian 9-month-olds. Infants in the experimental group displayed a robust preference for Caucasian faces when considered against the finding that infants in the control group displayed a spontaneous preference for other-race faces. The results offer confirmation that between 6 and 9 months, infants transition to representing own-race versus other-race face categories, with the latter inclusive of multiple other-race face classes with clear perceptual differences. Computational modeling of infant responding suggests that the developmental change is rooted in the statistics of experience with majority versus minority group faces.

More human than human: a Turing test for photographed faces

Background

Recent experimental work has shown that hyper-realistic face masks can pass for real faces during live viewing. However, live viewing embeds the perceptual task (mask detection) in a powerful social context that may influence respondents’ behaviour. To remove this social context, we assessed viewers’ ability to distinguish photos of hyper-realistic masks from photos of real faces in a computerised two-alternative forced choice (2AFC) procedure.

Results

In experiment 1 (N = 120), we observed an error rate of 33% when viewing time was restricted to 500 ms. In experiment 2 (N = 120), we observed an error rate of 20% when viewing time was unlimited. In both experiments we saw a significant performance cost for other-race comparisons relative to own-race comparisons.

Conclusions

We conclude that viewers could not reliably distinguish hyper-realistic face masks from real faces in photographic presentations. As well as its theoretical interest, failure to detect synthetic faces has important implications for security and crime prevention, which often rely on facial appearance and personal identity being related.

Face perception: A brief journey through recent discoveries and current directions

Faces are a rich source of information about the people around us. Identity, state of mind, emotions, intentions, age, gender, ethnic background, attractiveness and a host of other attributes about an individual can be gleaned from a face. When face perception fails, dramatic psycho-social consequences can follow at the individual level, as in the case of prosopagnosic parents who are unable to recognize their children at school pick-up. At the species level, social interaction patterns are shaped by human face perception abilities. The computational feat of recognizing faces and facial attributes, and the challenges overcome by the human brain to achieve this feat, have fascinated generations of vision researchers. In this paper, we present a brief overview of some of the milestones of discovery as well as outline a selected set of current directions and open questions on this topic.

Learning context and the other-race effect: Strategies for improving face recognition

People recognize faces of their own race more accurately than faces of other races-a phenomenon known as the "Other-Race Effect" (ORE). Previous studies show that training with multiple variable images improves face recognition. Building on multi-image training, we take a novel approach to improving own- and other-race face recognition by testing the role of learning context on accuracy. Learning context was either contiguous, with multiple images of each identity seen in sequence, or distributed, with multiple images of an identity randomly interspersed among different identities. In two experiments, East Asian and Caucasian participants learned own- and other-races faces either in a contiguous or distributed order. In Experiment 1, people learned each identity from four highly variable face images. In Experiment 2, identities were learned from one image, repeated four times. In both experiments we found a robust other-race effect. The effect of learning context, however, differed depending on the variability of the learned images. The distributed presentation yielded better recognition when people learned from single repeated images (Exp. 1), but not when they learned from multiple variable images (Exp. 2). Overall, performance was better with multiple-image training than repeated single image training. We conclude that multiple-image training and distributed learning can both improve recognition accuracy, but via distinct processes. The former broadens perceptual tolerance for image variation from a face, when there are diverse images available to learn. The latter effectively strengthens the representation of differences among similar faces, when there is only a single learning image.

Encoding differences affect the number and precision of own-race versus other-race faces stored in visual working memory

Other-race faces are discriminated and recognized less accurately than own-race faces. Despite a wealth of research characterizing this other-race effect (ORE), little is known about the nature of the representations of own-race versus other-race faces. This is because traditional measures of this ORE provide a binary measure of discrimination or recognition (correct/incorrect), failing to capture potential variation in the quality of face representations. We applied a novel continuous-response paradigm to independently measure the number of own-race and other-race face representations stored in visual working memory (VWM) and the precision with which they are stored. Participants reported target own-race or other-race faces on a circular face space that smoothly varied along the dimension of identity. Using probabilistic mixture modeling, we found that following ample encoding time, the ORE is attributable to differences in the probability of a face being maintained in VWM. Reducing encoding time, a manipulation that is more sensitive to encoding limitations, caused a loss of precision or an increase in variability of VWM for other-race but not own-race faces. These results suggest that the ORE is driven by the inefficiency with which other-race faces are rapidly encoded in VWM and provide novel insights about how perceptual experience influences the representation of own-race and other-race faces in VWM.

Systems Factorial Technology provides new insights on the other-race effect

The other-race effect refers to the difficulty of discriminating between faces from ethnic and racial groups other than one's own. This effect may be caused by a slow, feature-by-feature, analytic process, whereas the discrimination of own-race faces occurs faster and more holistically. However, this distinction has received inconsistent support. To provide a critical test, we employed Systems Factorial Technology (Townsend & Nozawa in Journal of Mathematical Psychology, 39, 321-359, 1995), which is a powerful tool for analyzing the organization of mental networks underlying perceptual processes. We compared Taiwanese participants' face discriminations of both own-race (Taiwanese woman) and other-race (Caucasian woman) faces according to the faces' nose-to-mouth separation and eye-to-eye separation. We found evidence for weak holistic processing (parallel processing) coupled with the strong analytic property of a self-terminating stopping rule for own-race faces, in contrast to strong analytic processing (serial self-terminating processing) for other-race faces, supporting the holistic/analytic hypothesis.

Tolerance to spatial-relational transformations in unfamiliar faces: A further challenge to a configural processing account of identity recognition

One of the most important questions in face perception research is to understand what information is extracted from a face in order to recognize its identity. Recognition of facial identity has been attributed to a special sensitivity to "configural" information. However, recent studies have challenged the configural account by showing that participants are poor in discriminating variations of metric distances among facial features, especially for familiar as opposed to unfamiliar faces, whereas a configural account predicts the opposite. We aimed to extend these previous results by examining classes of unfamiliar faces with which we have different levels of expertise. We hypothesized an inverse relation between sensitivity to configural information and expertise with a given class of faces, but only for neutral expressions. By first matching perceptual discriminability, we measured tolerance to subtle configural transformations with same-race (SR) versus other-race (OR) faces, and with upright versus upside-down faces. Consistently with our predictions, we found a lower sensitivity to at-threshold configural changes for SR compared to OR faces. We also found that, for our stimuli, the face inversion effect disappeared for neutral but not for emotional faces - a result that can also be attributed to a lower sensitivity to configural transformations for faces presented in a more familiar orientation. The present findings question a purely configural account of face processing and suggest that the role of spatial-relational information in face processing varies according to the functional demands of the task and to the characteristics of the stimuli.

A regional composite-face effect for species-specific recognition: Upper and lower halves play different roles in holistic processing of monkey faces

Using a composite-face paradigm, we examined the holistic processing induced by Asian faces, Caucasian faces, and monkey faces with human Asian participants in two experiments. In Experiment 1, participants were asked to judge whether the upper halves of two faces successively presented were the same or different. A composite-face effect was found for Asian faces and Caucasian faces, but not for monkey faces. In Experiment 2, participants were asked to judge whether the lower halves of the two faces successively presented were the same or different. A composite-face effect was found for monkey faces as well as for Asian faces and Caucasian faces. Collectively, these results reveal that own-species (i.e., own-race and other-race) faces engage holistic processing in both upper and lower halves of the face, but other-species (i.e., monkey) faces engage holistic processing only when participants are asked to match the lower halves of the face. The findings are discussed in the context of a region-based holistic processing account for the species-specific effect in face recognition.

Cross-race correlations in the abilities to match unfamiliar faces

The other-race effect in face identification has been documented widely in memory tasks, but it persists also in identity-matching tasks, in which memory contributions are minimized. Whereas this points to a perceptual locus for this effect, it remains unresolved whether matching performance with same- and other-race faces is driven by shared cognitive mechanisms. To examine this question, this study compared Arab and Caucasian observers' ability to match faces of their own race with their ability to match faces of another race using one-to-one (Experiment 1) and one-to-many (Experiment 2) identification tasks. Across both experiments, Arab and Caucasian observers demonstrated reliable other-race effects at a group level. At an individual level, substantial variation in accuracy was found, but performance with same-race and other-race faces correlated consistently and strongly. This indicates that the abilities to match same- and other-race faces share a common cognitive mechanism.

Crucial information for efficient face searching by humans and Japanese macaques

Humans can efficiently detect a face among non-face objects, but few studies of this ability have been conducted in animals. Here, in Japanese macaques and humans, we examined visual searching for a face and explored what factors contribute to efficient facial information processing. Subjects were asked to search for an odd target among the different numbers of distracters. Faces of the subjects' own species, the backs of the head of the subjects' own species, faces of the subjects' closely related species or race, and faces of species that are clearly different from the subjects' own species were used as the target. Both the macaques and humans detected a face of their own species more efficiently than a face from a clearly different species. Similar efficient detections were confirmed for the faces of the subjects' closely related species or race. These results suggest that conspecific faces and faces that share morphological similarity with conspecific faces can be detected efficiently among non-face objects by both humans and Japanese macaques. In another experiment, facial recognition efficiency was observed when the subjects searched for own-species faces that had lower-spatial-frequency components compared to faces with higher-spatial-frequency components. It seems reasonable that the ability to search efficiently for faces by using holistic face processing is derived from fundamental social cognition abilities that are broadly shared among species.

The other-race effect in face learning: Using naturalistic images to investigate face ethnicity effects in a learning paradigm

The other-race effect in face identification has been reported in many situations and by many different ethnicities, yet it remains poorly understood. One reason for this lack of clarity may be a limitation in the methodologies that have been used to test it. Experiments typically use an old-new recognition task to demonstrate the existence of the other-race effect, but such tasks are susceptible to different social and perceptual influences, particularly in terms of the extent to which all faces are equally individuated at study. In this paper we report an experiment in which we used a face learning methodology to measure the other-race effect. We obtained naturalistic photographs of Chinese and Caucasian individuals, which allowed us to test the ability of participants to generalize their learning to new ecologically valid exemplars of a face identity. We show a strong own-race advantage in face learning, such that participants required many fewer trials to learn names of own-race individuals than those of other-race individuals and were better able to identify learned own-race individuals in novel naturalistic stimuli. Since our methodology requires individuation of all faces, and generalization over large image changes, our finding of an other-race effect can be attributed to a specific deficit in the sensitivity of perceptual and memory processes to other-race faces.

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.

Experience with headwear influences the other-race effect in 4-year-old children

The other-race effect (ORE) implies the better recognition of faces of one's own race compared with faces of a different race. It demonstrates that face recognition is shaped by daily experience with human faces. Such experience mainly includes structural information of own-race faces and also information on the way faces are usually seen, as a whole or partly covered by scarves or other headwear. In two experiments, we investigated how this mode of presentation is related to the occurrence of the ORE during childhood. In Experiment 1, 4-year-old German children (N = 104), accustomed to seeing faces without headwear in daily life, were asked to recognize female Caucasian or African faces, presented either as a whole or wearing a woolen hat, in a forced choice paradigm. In Experiment 2, 4-year-olds from rural Cameroon (N = 70), accustomed to seeing faces with and without headwear in daily life, participated in the same task. In both groups, the ORE was present in the familiar mode of presentation, that is, in whole faces in German children and in whole and partly covered faces in Cameroonian children. The results are discussed in relation to the role of experience for face recognition processes.

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.

Processing of configural and componential information in face-selective cortical areas

We investigated how face-selective cortical areas process configural and componential face information and how race of faces may influence these processes. Participants saw blurred (preserving configural information), scrambled (preserving componential information), and whole faces during fMRI scan, and performed a post-scan face recognition task using blurred or scrambled faces. The fusiform face area (FFA) showed stronger activation to blurred than to scrambled faces, and equivalent responses to blurred and whole faces. The occipital face area (OFA) showed stronger activation to whole than to blurred faces, which elicited similar responses to scrambled faces. Therefore, the FFA may be more tuned to process configural than componential information, whereas the OFA similarly participates in perception of both. Differences in recognizing own- and other-race blurred faces were correlated with differences in FFA activation to those faces, suggesting that configural processing within the FFA may underlie the other-race effect in face recognition.

Developing Race Categories in Infancy via Bayesian Face Recognition

The other-race effect emerges during infancy following the perceptual narrowing of face recognition. Other-race faces that were previously discriminable in early infancy cannot be distinguished by older infants. Presently, I discuss a Bayesian model of this process that posits that the other-race effect may be a consequence of learning to distinguish between intra-personal variation (changes to face appearance that preserve identity) and extra-personal variation (changes that do not preserve identity) in a visual environment in which a subset of race categories dominate. I demonstrate that race categories, which I have previously argued are a critical pre-cursor to the emergence of the other-race effect in infancy, are a natural by-product of this model. Perceptual narrowing for race may thus be a natural consequence of visual experience and the estimation of face variability based on a growing number of exemplars. I describe the basic architecture of the model, its applicability to a range of visual learning scenarios, and identify critical choices one faces in applying the model to a specific perceptual task. Despite the success of the model in accounting for these behavioral results, I conclude by identifying important shortcomings of the model and describe important challenges for future efforts to characterize the development of the other-race effect computationally.