The discrimination of expressions in facial movements by infants: A study with point-light displays.

Perceiving facial expressions is an essential ability for infants. Although previous studies indicated that infants could perceive emotion from expressive facial movements, the developmental change of this ability remains largely unknown. To exclusively examine infants' processing of facial movements, we used point-light displays (PLDs) to present emotionally expressive facial movements. Specifically, we used a habituation and visual paired comparison (VPC) paradigm to investigate whether 3-, 6-, and 9-month-olds could discriminate between happy and fear PLDs after being habituated with a happy PLD (happy-habituation condition) or a fear PLD (fear-habituation condition). The 3-month-olds discriminated between the happy and fear PLDs in both the happy- and fear-habituation conditions. The 6- and 9-month-olds showed discrimination only in the happy-habituation condition but not in the fear-habituation condition. These results indicated a developmental change in processing expressive facial movements. Younger infants tended to process low-level motion signals regardless of the depicted emotions, and older infants tended to process expressions, which emerged in familiar facial expressions (e.g., happy). Additional analyses of individual difference and eye movement patterns supported this conclusion. In Experiment 2, we concluded that the findings of Experiment 1 were not due to a spontaneous preference for fear PLDs. Using inverted PLDs, Experiment 3 further suggested that 3-month-olds have already perceived PLDs as face-like stimuli.

Older but not younger infants associate own-race faces with happy music and other-race faces with sad music.

We used a novel intermodal association task to examine whether infants associate own- and other-race faces with music of different emotional valences. Three- to 9-month-olds saw a series of neutral own- or other-race faces paired with happy or sad musical excerpts. Three- to 6-month-olds did not show any specific association between face race and music. At 9 months, however, infants looked longer at own-race faces paired with happy music than at own-race faces paired with sad music. Nine-month-olds also looked longer at other-race faces paired with sad music than at other-race faces paired with happy music. These results indicate that infants with nearly exclusive own-race face experience develop associations between face race and music emotional valence in the first year of life. The potential implications of such associations for developing racial biases in early childhood are discussed.

Infants Rely More on Gaze Cues From Own-Race Than Other-Race Adults for Learning Under Uncertainty.

Differential experience leads infants to have perceptual processing advantages for own- over other-race faces, but whether this experience has downstream consequences is unknown. Three experiments examined whether 7-month-olds (range = 5.9-8.5 months; N = 96) use gaze from own- versus other-race adults to anticipate events. When gaze predicted an event's occurrence with 100% reliability, 7-month-olds followed both adults equally; with 25% (chance) reliability, neither was followed. However, with 50% (uncertain) reliability, infants followed own- over other-race gaze. Differential face race experience may thus affect how infants use social cues from own- versus other-race adults for learning. Such findings suggest that infants integrate online statistical reliability information with prior knowledge of own versus other race to guide social interaction and learning.

The applicability of eye-controlled highlighting to the field of visual searching.

OBJECTIVE: With the increasing amount of information presented on current human-computer interfaces, eye-controlled highlighting has been proposed, as a new display technique, to optimise users' task performances. However, it is unknown to what extent the eye-controlled highlighting display facilitates visual search performance. The current study examined the facilitative effect of eye-controlled highlighting display technique on visual search with two major attributes of visual stimuli: stimulus type and the visual similarity between targets and distractors. METHOD: In Experiment 1, we used digits and Chinese words as materials to explore the generalisation of the facilitative effect of the eye-controlled highlighting. In Experiment 2, we used Chinese words to examine the effect of target-distractor similarity on the facilitation of eye-controlled highlighting display. RESULTS: The eye-controlling highlighting display improved visual search performance when words were used as searching target and when the target-distractor similarity was high. No facilitative effect was found when digits were used as searching target or target-distractor similarity was low. CONCLUSIONS: The effectiveness of the eye-controlled highlighting on a visual task was influenced by both stimulus type and target-distractor similarity. These findings provided guidelines for modern interface design with eye-based displays implemented.

Development of Recognition of Face Parts from Unfamiliar Faces.

The present study examined developmental changes in the ability to recognize face parts. In Experiment 1, participants were familiarized with whole faces and given a recognition test with old and new eyes, noses, mouths, inner faces, outer faces, or whole faces. Adults were above chance in their recognition of the eye and mouth regions. However, children did not naturally encode and recognize face parts independently of the entire face. In addition, all age groups showed comparable inner and outer face recognition, except for 8- to 9-year-olds who showed a recognition advantage for outer faces. In Experiment 2, when participants were familiarized with eyes, noses, or mouths and tested with eyes, noses, or mouths, respectively, all ages showed above-chance recognition of eyes and mouths. Thirteen- to 14-year-olds were adult-like in their recognition of the eye region, but mouth recognition continued to develop beyond 14 years of age. Nose recognition was above chance among 13- to 14-year-olds, but recognition scores remained low even in adulthood. The present findings reveal unique developmental trajectories in the use of isolated facial regions in face recognition and suggest that featural cues (as a class) have a different ontogenetic course relative to holistic and configural cues.

Developing cultural differences in face processing.

Perception and eye movements are affected by culture. Adults from Eastern societies (e.g. China) display a disposition to process information holistically, whereas individuals from Western societies (e.g. Britain) process information analytically. Recently, this pattern of cultural differences has been extended to face processing. Adults from Eastern cultures fixate centrally towards the nose when learning and recognizing faces, whereas adults from Western societies spread fixations across the eye and mouth regions. Although light has been shed on how adults can fixate different areas yet achieve comparable recognition accuracy, the reason why such divergent strategies exist is less certain. Although some argue that culture shapes strategies across development, little direct evidence exists to support this claim. Additionally, it has long been claimed that face recognition in early childhood is largely reliant upon external rather than internal face features, yet recent studies have challenged this theory. To address these issues, we tested children aged 7-12 years of age from the UK and China with an old/new face recognition paradigm while simultaneously recording their eye movements. Both populations displayed patterns of fixations that were consistent with adults from their respective cultural groups, which 'strengthened' across development as qualified by a pattern classifier analysis. Altogether, these observations suggest that cultural forces may indeed be responsible for shaping eye movements from early childhood. Furthermore, fixations made by both cultural groups almost exclusively landed on internal face regions, suggesting that these features, and not external features, are universally used to achieve face recognition in childhood.

Similarity and difference in the processing of same- and other-race faces as revealed by eye tracking in 4- to 9-month-olds.

Fixation duration for same-race (i.e., Asian) and other-race (i.e., Caucasian) female faces by Asian infant participants between 4 and 9 months of age was investigated with an eye-tracking procedure. The age range tested corresponded with prior reports of processing differences between same- and other-race faces observed in behavioral looking time studies, with preference for same-race faces apparent at 3 months of age and recognition memory differences in favor of same-race faces emerging between 3 and 9 months of age. The eye-tracking results revealed both similarity and difference in infants' processing of own- and other-race faces. There was no overall fixation time difference between same race and other race for the whole face stimuli. In addition, although fixation time was greater for the upper half of the face than for the lower half of the face and trended higher on the right side of the face than on the left side of the face, face race did not impact these effects. However, over the age range tested, there was a gradual decrement in fixation time on the internal features of other-race faces and a maintenance of fixation time on the internal features of same-race faces. Moreover, the decrement in fixation time for the internal features of other-race faces was most prominent on the nose. The findings suggest that (a) same-race preferences may be more readily evidenced in paired comparison testing formats, (b) the behavioral decline in recognition memory for other-race faces corresponds in timing with a decline in fixation on the internal features of other-race faces, and (c) the center of the face (i.e., the nose) is a differential region for processing same- versus other-race faces by Asian infants.

Using eye-controlled highlighting techniques to support both serial and parallel processing in visual search.

Recent research has developed two eye-controlled highlighting techniques, namely, block highlight display (BHD) and single highlight display (SHD), that enhance information presentation based on a user's current gaze position. The present research aimed to investigate how these techniques facilitate mental processing of users' visual search in high information-density visual environments. In Experiment 1, 60 participants performed 3-, 6-, 9-, and 12-icon visual search tasks. The search times significantly increased as the number of icons increased with the SHD but not with the BHD. In Experiment 2, 40 participants performed a 49-icon visual search task. The search time was faster, and the fixation spatial density was lower with the BHD than with the SHD. These results suggested that the BHD supported parallel processing in the highlighted area and serial processing in the broader display area; thus, the BHD improved search performance compared to the SHD, which primarily supported serial processing.

Development of the other-race effect during infancy: evidence toward universality?

The other-race effect in face processing develops within the first year of life in Caucasian infants. It is currently unknown whether the developmental trajectory observed in Caucasian infants can be extended to other cultures. This is an important issue to investigate because recent findings from cross-cultural psychology have suggested that individuals from Eastern and Western backgrounds tend to perceive the world in fundamentally different ways. To this end, the current study investigated 3-, 6-, and 9-month-old Chinese infants' ability to discriminate faces within their own racial group and within two other racial groups (African and Caucasian). The 3-month-olds demonstrated recognition in all conditions, whereas the 6-month-olds recognized Chinese faces and displayed marginal recognition for Caucasian faces but did not recognize African faces. The 9-month-olds' recognition was limited to Chinese faces. This pattern of development is consistent with the perceptual narrowing hypothesis that our perceptual systems are shaped by experience to be optimally sensitive to stimuli most commonly encountered in one's unique cultural environment.

The roles of visual expertise and visual input in the face inversion effect: behavioral and neurocomputational evidence.

Research has shown that inverting faces significantly disrupts the processing of configural information, leading to a face inversion effect. We recently used a contextual priming technique to show that the presence or absence of the face inversion effect can be determined via the top-down activation of face versus non-face processing systems [Ge, L., Wang, Z., McCleery, J., & Lee, K. (2006). Activation of face expertise and the inversion effect. Psychological Science, 17(1), 12-16]. In the current study, we replicate these findings using the same technique but under different conditions. We then extend these findings through the application of a neural network model of face and Chinese character expertise systems. Results provide support for the hypothesis that a specialized face expertise system develops through extensive training of the visual system with upright faces, and that top-down mechanisms are capable of influencing when this face expertise system is engaged.

An inner face advantage in children's recognition of familiar peers.

Children's recognition of familiar own-age peers was investigated. Chinese children (4-, 8-, and 14-year-olds) were asked to identify their classmates from photographs showing the entire face, the internal facial features only, the external facial features only, or the eyes, nose, or mouth only. Participants from all age groups were familiar with the faces used as stimuli for 1 academic year. The results showed that children from all age groups demonstrated an advantage for recognition of the internal facial features relative to their recognition of the external facial features. Thus, previous observations of a shift in reliance from external to internal facial features can be attributed to experience with faces rather than to age-related changes in face processing.

The Effect of Romantic Relationships on the Evaluation of the Attractiveness of One's Own Face.

The present study sought to explore the effect of romantic relationships on the attractiveness evaluation of one's own face using two experiments with the probability evaluation and the subjective rating method. Experiment 1 and Experiment 2 enrolled couples and single individuals as participants, respectively. The results of the two experiments indicated that the participants evaluated their own face as significantly more attractive than did others of the same sex. More importantly, the romantic relationship enhanced the positive bias in the evaluation of self-face attractiveness, that is, couple participants showed a stronger positive bias than did single individuals. It was also found that a person in a romantic relationship was prone to overestimating the attractiveness of his or her lover's face, from the perspective of both probability evaluation and rating score. However, the abovementioned overestimation did not surpass the evaluations of the exaggeratedly attractive face. The present results supported the observer hypothesis, demonstrating the romantic relationship to be an important influential factor of facial attractiveness. Our findings have important implications for the research of self-face evaluation.

Facial movements facilitate part-based, not holistic, processing in children, adolescents, and adults.

Although most of the faces we encounter daily are moving ones, much of what we know about face processing and its development is based on studies using static faces that emphasize holistic processing as the hallmark of mature face processing. Here the authors examined the effects of facial movements on face processing developmentally in children (8-year-olds), adolescents (12-year-olds), and adults (20-year-olds). In particular, the composite face effect was used to measure the influence of facial movements on part-based versus holistic processing after participants had viewed either a moving or static face in a within-subject design. Experiment 1 examined elastic facial movement (i.e., blinking and chewing). The results showed that children, adolescents, and adults exhibited a significantly smaller composite effect after viewing a moving face than after viewing a static face. This result indicates that elastic facial movement facilitates part-based face processing from at least 8 years of age onward. Experiment 2 examined rigid facial movement (i.e., head turning) and revealed that it too facilitates part-based face processing in children, adolescents, and adults. The results taken together suggest that contrary to the prevailing view, facial movements facilitate part-based, not holistic, face processing in children, adolescents, and adults. The findings call for revision in the conventional way of thinking about what constitutes the developmental trajectory toward mature face processing and also point to the importance of using more naturalistic moving face stimuli to study face processing and its development. (PsycINFO Database Record

Facial Contrast Is a Cross-Cultural Cue for Perceiving Age.

Age is a fundamental social dimension and a youthful appearance is of importance for many individuals, perhaps because it is a relevant predictor of aspects of health, facial attractiveness and general well-being. We recently showed that facial contrast-the color and luminance difference between facial features and the surrounding skin-is age-related and a cue to age perception of Caucasian women. Specifically, aspects of facial contrast decrease with age in Caucasian women, and Caucasian female faces with higher contrast look younger (Porcheron et al., 2013). Here we investigated faces of other ethnic groups and raters of other cultures to see whether facial contrast is a cross-cultural youth-related attribute. Using large sets of full face color photographs of Chinese, Latin American and black South African women aged 20-80, we measured the luminance and color contrast between the facial features (the eyes, the lips, and the brows) and the surrounding skin. Most aspects of facial contrast that were previously found to decrease with age in Caucasian women were also found to decrease with age in the other ethnic groups. Though the overall pattern of changes with age was common to all women, there were also some differences between the groups. In a separate study, individual faces of the 4 ethnic groups were perceived younger by French and Chinese participants when the aspects of facial contrast that vary with age in the majority of faces were artificially increased, but older when they were artificially decreased. Altogether these findings indicate that facial contrast is a cross-cultural cue to youthfulness. Because cosmetics were shown to enhance facial contrast, this work provides some support for the notion that a universal function of cosmetics is to make female faces look younger.

Reproducibility of frequency-dependent low frequency fluctuations in reaction time over time and across tasks.

OBJECTIVE: Increased levels of reaction time variability (RTV) are characteristics of sustained attention deficits. The clinical significance of RTV has been widely recognized. However, the reliability of RTV measurements has not been widely studied. The present study aimed to assess the test-retest reliability of RTV conventional measurements, e.g., the standard deviation (SD), the coefficient of variation (CV), and a new measurement called the amplitude of low frequency fluctuation (ALFF) of RT. In addition, we aimed to assess differences and similarities of these measurements between different tasks. METHOD: Thirty-seven healthy college students participated in 2 tasks, i.e., an Eriksen flanker task (EFT) and a simple reaction task (SRT), twice over a mean interval of 56 days. Conventional measurements of RTV including RT-SD and RT-CV were assessed first. Then the RT time series were converted into frequency domains, and RT-ALFF was further calculated for the whole frequency band (0.0023-0.167 Hz) and for a few sub-frequency bands including Slow-6 (<0.01 Hz), Slow-5 (0.01-0.027 Hz), Slow-4 (0.027-0.073 Hz), and Slow-3 (0.073-0.167 Hz). The test-retest reliability of these measurements was evaluated through intra-class correlation (ICC) tests. Differences and correlations between each EFT and SRT measurement were further examined during both visits. RESULTS: 1) The RT-ALFF of the Slow-5/4/3 and conventional measurements of RT-SD and RT-CV showed moderate to high levels of test-retest reliability. EFT RT-ALFF patterns generated slightly higher ICC values than SRT values in higher frequency bands (Slow-3), but SRT RT-ALFF values showed slightly higher ICC values than EFT values in lower frequency bands (Slow-5 and Slow-4). 2) RT-ALFF magnitudes in each sub-frequency band were greater for the SRT than those for the EFT. 3) The RT-ALFF in the Slow-4 of the EFT was found to be correlated with the RT-ALFF in the Slow-5 of the SRT for both two visits, but no consistently significant correlation was found between the same frequency bands. CONCLUSIONS: These findings reveal good test-retest reliability for conventional measurements and for the RT-ALFF of RTV. The RT-ALFF presented frequency-dependent similarities across tasks. All of our results reveal the presence of different frequency structures between the two tasks, and thus the frequency-dependent characteristics of different tasks deserve more attention in future studies.

Colours' Impact on Morality: Evidence from Event-related Potentials.

Black and white have been shown to be representations of moral concepts. The purpose of this study was to investigate whether colours other than black and white have similar effects on words related to morality and to determine the time course of these effects. We presented moral and immoral words in three colours (red, green and blue) in a Moral Stroop task and used the event-related potential (ERP) technique to identify the temporal dynamics of the impact of colours on moral judgement. The behavioural results showed that it took longer for people to judge immoral words than moral words when the words were coloured green than when they were red or blue. The ERP results revealed the time course of these effects. Three stages were identified in the significant effects of P200, N300 and LPC. These findings suggest a metaphorical association between the colour green and moral information.

Eye tracking reveals a crucial role for facial motion in recognition of faces by infants.

Current knowledge about face processing in infancy comes largely from studies using static face stimuli, but faces that infants see in the real world are mostly moving ones. To bridge this gap, 3-, 6-, and 9-month-old Asian infants (N = 118) were familiarized with either moving or static Asian female faces, and then their face recognition was tested with static face images. Eye-tracking methodology was used to record eye movements during the familiarization and test phases. The results showed a developmental change in eye movement patterns, but only for the moving faces. In addition, the more infants shifted their fixations across facial regions, the better their face recognition was, but only for the moving faces. The results suggest that facial movement influences the way faces are encoded from early in development.

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.

An other-race effect for configural and featural processing of faces: upper and lower face regions play different roles.

We examined whether Asian individuals would show differential sensitivity to configural vs. featural changes to own- and other-race faces and whether such sensitivity would depend on whether the changes occurred in the upper vs. lower regions of the faces. We systematically varied the size of key facial features (eyes and mouth) of own-race Asian faces and other-race Caucasian faces, and the configuration (spacing) between the eyes and between the nose and mouth of the two types of faces. Results revealed that the other-race effect (ORE) is more pronounced when featural and configural spacing changes are in the upper region than in the lower region of the face. These findings reveal that information from the upper vs. lower region of the face contributes differentially to the ORE in face processing, and that processing of face race is influenced more by information location (i.e., upper vs. lower) than by information type (i.e., configural vs. featural).

Development of visual preference for own- versus other-race faces in infancy.

Previous research has shown that 3-month-olds prefer own- over other-race faces. The current study used eye-tracking methodology to examine how this visual preference develops with age beyond 3 months and how infants differentially scan between own- and other-race faces when presented simultaneously. We showed own- versus other-race face pairs to 3-, 6-, and 9-month-old Chinese infants. In contrast with 3-month-olds' visual preference for own-race faces, 9-month-olds preferentially looked more at other-race faces. Analyses of eye-tracking data revealed that Chinese infants processed own- and other-race faces differentially. These findings shed important light on the role of visual experience in the development of visual preference and its relation to perceptual narrowing.