Face Adaptation and Attractiveness Aftereffects in 8-Year-Olds and Adults

Religious labels and food preferences, but not country of origin, support opposing face aftereffects

Face templates can be experimentally manipulated, and category-contingent aftereffects suggest discrete templates across social groups. We tested whether 1) explicit religious labels, 2) food preferences, and 3) country of origin would support religion-contingent aftereffects across Christians and Muslims face sets. While viewing face images, ninety-three participants heard audio that stated either 1) a character's religious identity, 2) preferred food, or 3) country of origin. Participants viewed contracted Christian faces and expanded Muslim faces during the training phase. To measure adaptation, before and after the training phases, participants selected the face out of a pair of expanded and contracted Christian or Muslim faces that they found more attractive. Contingent aftereffects were found in the religious explicit (t(30) = 2.49, p = 0.02, Cohen's d = 0.58) and food conditions (t(30) = -3.77, p < 0.01, Cohen's d = -0.82), but not the country condition (t(30) = 1.64, p = 0.11, Cohen's d = 0.31). This suggests that religious labels and food preferences create socially meaningful groups, but country of origin does not. This is evidence of an impact of social categorization on visual processing.

Minimal gains for minimal pairs: Difficulty in learning similar-sounding words continues into preschool

A critical indicator of spoken language knowledge is the ability to discern the finest possible distinctions that exist between words in a language-minimal pairs, for example, the distinction between the novel words beesh and peesh. Infants differentiate similar-sounding novel labels like "bih" and "dih" by 17 months of age or earlier in the context of word learning. Adult word learners readily distinguish similar-sounding words. What is unclear is the shape of learning between infancy and adulthood: Is there a nonlinear increase early in development, or is there protracted improvement as experience with spoken language amasses? Three experiments tested monolingual English-speaking children aged 3 to 6 years and young adults. Children underperformed when learning minimal-pair words compared with adults (Experiment 1), compared with learning dissimilar words even when speech materials were optimized for young children (Experiment 2), and when the number of word instances during learning was quadrupled (Experiment 3). Nonetheless, the youngest group readily recognized familiar minimal pairs (Experiment 3). Results are consistent with a lengthy trajectory for detailed sound pattern learning in one's native language(s), although other interpretations are possible. Suggestions for research on developmental trajectories across various age ranges are made.

Altered mechanisms of adaptation in social anxiety: differences in adapting to positive versus negative emotional faces

Social anxiety is characterised by fear of negative evaluation and negative perceptual biases; however, the cognitive mechanisms underlying these negative biases are not well understood. We investigated a possible mechanism which could maintain negative biases: altered adaptation to emotional faces. Heightened sensitivity to negative emotions could result from weakened adaptation to negative emotions, strengthened adaptation to positive emotions, or both mechanisms. We measured adaptation from repeated exposure to either positive or negative emotional faces, in individuals high versus low in social anxiety. We quantified adaptation strength by calculating the point of subjective equality (PSE) before and after adaptation for each participant. We hypothesised: (1) weaker adaptation to angry vs happy faces in individuals high in social anxiety, (2) no difference in adaptation to angry vs happy faces in individuals low in social anxiety, and (3) no difference in adaptation to sad vs happy faces in individuals high in social anxiety. Our results revealed a weaker adaptation to angry compared to happy faces in individuals high in social anxiety (Experiment 1), with no such difference in individuals low in social anxiety (Experiment 1), and no difference in adaptation strength to sad vs happy faces in individuals high in social anxiety (Experiment 2).

A category contingent aftereffect for faces labelled with different religious affiliation is seen 7 days after adaptation

Visual adaptation occurs after a prolonged exposure to a stimulus. The duration of aftereffects differs across stimuli type, and face aftereffects may be especially long lasting. The current study investigates adaptation decay of category contingent opposing aftereffects. Specifically, we tested whether naïve undergraduate participants' adaptation to photos of faces with explicit religious labels, differed from that of participants who had adapted to the same faces 7 days previously. We also tested whether 7-day old category-contingent opposing aftereffects interfere with the ability to re-adapt to a new condition. In Session 1, undergraduates made attractiveness preference selections before and after adapting to two groups of distorted faces. Participants then returned 7 days later to re-assess the attractiveness of the same faces. Participants were then adapted to the two groups of faces distorted in the opposite direction. Adaptation strength was stronger in Session 1 than in Session 2, although adaptation strength was not related to pre-adaptation selections. Week-old aftereffects interfered with the creation of aftereffects in the opposite direction 7 days later.

Can realistic dolls protect body satisfaction in young girls?

Ultra-thin fashion dolls may represent a risk factor for thin-ideal internalisation and body dissatisfaction amongst young girls. We asked thirty one 5- to 9-year-old girls to engage in interactive play with commercially available dolls which were either ultra-thin (Barbie and Monster High) or represented a putative realistic childlike shape (Lottie and Dora) and to indicate their perceived own-body size and ideal body size on an interactive computer task both before and after play. There was a significant interaction between testing phase and doll group such that playing with the ultra-thin dolls led to the girls' 'ideal self' becoming thinner. A further 46 girls played with the ultra-thin dolls and then played with either the same dolls again, the realistic childlike dolls, or with cars. Initial play with the ultra-thin dolls again produced a drop in perceived ideal own body size; however, no group showed any significant change in their body ideals during the additional play phase. These data indicate the potential benefit of dolls representing a realistic child body mass to young girls' body satisfaction and do not support the hypothesis that the negative impacts of ultra-thin dolls can be directly countered by other toys.

The Role of Racial and Developmental Experience on Emotional Adaptive Coding in Autism Spectrum Disorder

Sensitivity to emotional face aids in rapid detection and evaluation of others, such that by school-age, children and youth exhibit adult-like patterns when the prolonged viewing of an emotional face distorts the perception of a subsequent face. However, the developmental considerations of this phenomenon (known as emotional adaptive coding) are unclear given ongoing maturational and experiential changes, including the influence of own-race experiences or the lack of face expertise, as is evident in autism spectrum disorder (ASD). This study addressed whether emotional adaptive coding is sensitive to factors of face perception expertise, specifically self-race and developmental experience, in adults (age 19-28 years) and youth (age 10-16 years). Emotional adaptive coding was not influenced by race expertise (i.e., other versus same race identity) in White and Asian adults. Emotional adaptation coding during childhood and adolescence is consistent with adults, though youth with ASD exhibited stronger adaptor after-effects in response to other-race faces, relative to TD youth and adults. By extending prior work to examine the integration of race and emotional adaptive coding in ASD, we discovered that the strength of response in ASD is atypical when viewing other-race faces, which clarifies the role of racial and facial experience on emotional face adaption.

The influence of subtle facial expressions on children's first impressions of trustworthiness and dominance is not adult-like

Adults' first impressions of others are influenced by subtle facial expressions; happy faces are perceived as high in trustworthiness, whereas angry faces are rated as low in trustworthiness and high in threat and dominance. Little is known about the influence of emotional expressions on children's first impressions. Here we examined the influence of subtle expressions of happiness, anger, and fear on children's implicit judgments of trustworthiness and dominance with the aim of providing novel insights about both the development of first impressions and whether children are able to utilize emotional expressions when making implicit, rather than explicit, judgments of traits. In the context of a computerized storybook, children (4- to 11-year-olds) and adults selected one of two twins (two images of the same identity displaying different emotional expressions) to help them face a challenge; some challenges required a trustworthy partner, and others required a dominant partner. One twin posed a neutral expression, and the other posed a subtle emotional expression of happiness, fear, or anger. Whereas adults were more likely to select a happy partner on trust trials than on dominance trials and were more likely to select an angry partner on dominance trials than on trust trials, we found no evidence that children's choices reflected a combined influence of desirable trait and emotion. Follow-up experiments involving explicit trait judgments, explicit emotion recognition, and implicit first impression judgments in the context of intense emotional expressions provide valuable insights into the slow development of implicit trait judgments based on first impressions.

Becoming Familiar With a Newly Encountered Face: Evidence of an Own-Race Advantage

Adults' ability to match identity in images of unfamiliar faces is impaired for other- compared with own-race faces; their ability to match identity in images of familiar faces is independent of face race. Exposure to within-person variability in appearance plays a key role in face learning. Past research suggests that children need exposure to higher levels of variability than adults to learn a new face-a difference that has been attributed to experience. We predicted that adults' limited experience with other-race faces would result in their needing exposure to higher levels of variability when learning other- compared with own-race faces. We introduced adults to four new identities (two own-race; two other-race) in one of the three conditions: a single image, a low-variability video (filmed on 1 day), or a high-variability video (filmed across 3 days). Adults' ability to recognize new instances of learned identities improved in the low-variability condition for own-race faces but only in the high-variability condition for other-race faces. We discuss learning mechanisms that might drive this difference-a difference we attribute to experience.

The aesthetic preference for symmetry dissociates from early-emerging attention to symmetry

Symmetry is a basic geometry property that affects people's aesthetic experience in common ways across cultures and historical periods, but the origins of the universal preference for symmetrical patterns is not clear. We assessed four-year-old children's and adults' reported aesthetic preferences between symmetrical and asymmetrical visual patterns, as well as their spontaneous attentional preferences between the patterns. We found a striking dissociation between these two measures in the children: Children looked longer at the symmetrical patterns, relative to otherwise similar but asymmetrical patterns, but they showed no explicit preference for those patterns. These findings suggest that the human's aesthetic preferences have high postnatal plasticity, calling into question theories that symmetry is a "core feature" mediating people's aesthetic experience throughout life. The findings also call into question the assumption, common to many studies of human infants, that attentional choices reflect subjective preferences or values.

Color Afterimages in Autistic Adults

It has been suggested that attenuated adaptation to visual stimuli in autism is the result of atypical perceptual priors (e.g., Pellicano and Burr in Trends Cogn Sci 16(10):504-510, 2012. doi: 10.1016/j.tics.2012.08.009 ). This study investigated adaptation to color in autistic adults, measuring both strength of afterimage and the influence of top-down knowledge. We found no difference in color afterimage strength between autistic and typical adults. Effects of top-down knowledge on afterimage intensity shown by Lupyan (Acta Psychol 161:117-130, 2015. doi: 10.1016/j.actpsy.2015.08.006 ) were not replicated for either group. This study finds intact color adaptation in autistic adults. This is in contrast to findings of attenuated adaptation to faces and numerosity in autistic children. Future research should investigate the possibility of developmental differences in adaptation and further examine top-down effects on adaptation.

Face Attractiveness versus Artistic Beauty in Art Portraits: A Behavioral Study

From art portraits, the observer may derive at least two different hedonic values: The attractiveness of the depicted person and the artistic beauty of the image that relates to the way of presentation. We argue that attractiveness is a property that is predominantly driven by perceptual processes, while the perception of artistic beauty is based predominantly on cognitive processing. To test this hypothesis, we conducted two behavioral experiments. In a gist study (Experiment 1), we showed that ratings on attractiveness were higher after short-term presentation (50 ms) than after long-term presentation (3000 ms), while the opposite pattern was found for artistic beauty. In an experiment on perceptual contrast (Experiment 2), we showed that the perceptual contrast effect was stronger for attractiveness than for artistic beauty. These results are compatible with our hypothesis that appreciation of artistic beauty is cognitively modulated at least in part, while processing of attractiveness is predominantly driven perceptually. This dichotomy between cognitive and perceptual processing of different kinds of beauty suggests the participation of different neuronal mechanisms.

Getting to know you: The development of mechanisms underlying face learning

Nearly every study investigating the development of face recognition has focused on the ability to tell people apart using one or two tightly controlled images to represent each identity. Such research ignores the challenge of recognizing the same person despite variability in appearance. Whereas natural variation in appearance makes unfamiliar faces difficult to recognize, by 6 years of age people easily recognize multiple images of familiar faces. Two mechanisms are proposed to underlie the process by which adults become familiar with newly encountered faces. We provide the first examination of the development of these mechanisms during childhood (6-11 years). In Experiment 1, we examined children's (6- to 10-year-olds') and adults' ability to engage in ensemble coding-the ability to rapidly extract an average representation of an identity from several instances. In Experiment 2, we examined children's ability to use within-person variability in appearance to recognize novel instances of a newly encountered identity. We created a child-friendly perceptual matching task, and the number of images to which participants were exposed varied across targets. Although children were less accurate than adults overall in Experiment 2, we found no age-related improvement in either ensemble coding or the ability to benefit from exposure to within-person variability in appearance when learning a new face, suggesting that both abilities are developed by 6 years of age. We discuss the implications of these findings for understanding the nature of mechanisms underlying face learning and other developmental processes such as language and music.

How does a newly encountered face become familiar? The effect of within-person variability on adults' and children's perception of identity

Adults and children aged 6years and older easily recognize multiple images of a familiar face, but often perceive two images of an unfamiliar face as belonging to different identities. Here we examined the process by which a newly encountered face becomes familiar, defined as accurate recognition of multiple images that capture natural within-person variability in appearance. In Experiment 1 we examined whether exposure to within-person variability in appearance helps children learn a new face. Children aged 6-13years watched a 10-min video of a woman reading a story; she was filmed on a single day (low variability) or over three days, across which her appearance and filming conditions (e.g., camera, lighting) varied (high variability). After familiarization, participants sorted a set of images comprising novel images of the target identity intermixed with distractors. Compared to participants who received no familiarization, children showed evidence of learning only in the high-variability condition, in contrast to adults who showed evidence of learning in both the low- and high-variability conditions. Experiment 2 highlighted the efficiency with which adults learn a new face; their accuracy was comparable across training conditions despite variability in duration (1 vs. 10min) and type (video vs. static images) of training. Collectively, our findings show that exposure to variability leads to the formation of a robust representation of facial identity, consistent with perceptual learning in other domains (e.g., language), and that the development of face learning is protracted throughout childhood. We discuss possible underlying mechanisms.

Six-month-old infant long sleepers prefer a human face

BACKGROUND

Sleep is known to influence socio-emotional regulation among children and preschoolers, whereas little is known about the association between sleep and social preference during infancy.

METHODS

In the current study, habitual sleep of 49 infants aged around six months old were surveyed by questionnaire, and their social preference was revealed by their preferential gaze in three conditions: (1) a human face paired with an object (ie, a cup), (2) a human face paired with an animal face (ie, a dog), and (3) a dog face paired with a cup.

RESULTS

In general, images with richer social information (ie, a human face and dog) attracted infants' gaze significantly more than nonsocial images (ie, cup). Infants with shorter sleep duration (ie, <13 h a day) show a significant reduction in their preference toward a human face when paired with a dog than infants with longer sleep duration.

CONCLUSIONS

Our findings suggest an early positive link between sleep duration and preference towards socially rich stimuli (eg, a human face) during infancy.

Judging Normality and Attractiveness in Faces: Direct Evidence of a More Refined Representation for Own-Race, Young Adult Faces

Young and older adults are more sensitive to deviations from normality in young than older adult faces, suggesting that the dimensions of face space are optimized for young adult faces. Here, we extend these findings to own-race faces and provide converging evidence using an attractiveness rating task. In Experiment 1, Caucasian and Chinese adults were shown own- and other-race face pairs; one member was undistorted and the other had compressed or expanded features. Participants indicated which member of each pair was more normal (a task that requires referencing a norm) and which was more expanded (a task that simply requires discrimination). Participants showed an own-race advantage in the normality task but not the discrimination task. In Experiment 2, participants rated the facial attractiveness of own- and other-race faces (Experiment 2a) or young and older adult faces (Experiment 2b). Between-rater variability in ratings of individual faces was higher for other-race and older adult faces; reduced consensus in attractiveness judgments reflects a less refined face space. Collectively, these results provide direct evidence that the dimensions of face space are optimized for own-race and young adult faces, which may underlie face race- and age-based deficits in recognition.

Adults with autism spectrum disorder show evidence of figural aftereffects with male and female faces

The norm-based coding model of face perception posits that face perception involves an implicit comparison of observed faces to a representation of an average face (prototype) that is shaped by experience. Using some methods, observers with autism spectrum disorder (ASD) have shown atypical face perception, but other methods suggest preserved face perception. Here, we used a figural aftereffects paradigm to test whether adults with ASD showed evidence of norm-based coding of faces, and whether they encode separate prototypes for male and female faces, as typical observers do. Following prolonged exposure to distorted faces that differ from their stored prototype, neurotypical adults show aftereffects: their prototype shifts in the direction of the adapting face. We measured aftereffects following adaptation to one distorted gender. There were no significant group differences in the size or direction of the aftereffects; both groups showed sex-selective aftereffects after adapting to expanded female faces but showed aftereffects for both sexes after adapting to contracted face of either sex, demonstrating that adults with and without ASD show evidence of partially dissociable male and female face prototypes. This is the first study to examine sex-selective prototypes using figural aftereffects in adults with ASD and replicates the findings of previous studies examining aftereffects in adults with ASD. The results contrast with studies reporting diminished adaptation in children with ASD.

Children (but not adults) judge similarity in own- and other-race faces by the color of their skin

Both face shape and pigmentation are diagnostic cues for face identification and categorization. In particular, both shape and pigmentation contribute to observers' categorization of faces by race. Although many theoretical accounts of the behavioral other-race effect either explicitly or implicitly depend on differential use of visual information as a function of category expertise, there is little evidence that observers do in fact differentially rely on distinct visual cues for own- and other-race faces. In the current study, we examined how Asian and Caucasian children (4-6 years of age) and adults use three-dimensional shape and two-dimensional pigmentation to make similarity judgments of White, Black, and Asian faces. Children in this age range are capable of making category judgments about race but also are sufficiently plastic with regard to the behavioral other-race effect that it seems as though their representations of facial appearance across different categories are still emerging. Using a simple match-to-sample similarity task, we found that children tend to use pigmentation to judge facial similarity more than adults and also that own-group versus other-group category membership appears to influence how quickly children learn to use shape information more readily. Therefore, we suggest that children continue to adjust how different visual information is weighted during early and middle childhood and that experience with faces affects the speed at which adult-like weightings are established.

Attractiveness judgments and discrimination of mommies and grandmas: perceptual tuning for young adult faces

Adults are more accurate in detecting deviations from normality in young adult faces than in older adult faces despite exhibiting comparable accuracy in discriminating both face ages. This deficit in judging the normality of older faces may be due to reliance on a face space optimized for the dimensions of young adult faces, perhaps because of early and continuous experience with young adult faces. Here we examined the emergence of this young adult face bias by testing 3- and 7-year-old children on a child-friendly version of the task used to test adults. In an attractiveness judgment task, children viewed young and older adult face pairs; each pair consisted of an unaltered face and a distorted face of the same identity. Children pointed to the prettiest face, which served as a measure of their sensitivity to the dimensions on which faces vary relative to a norm. To examine whether biases in the attractiveness task were specific to deficits in referencing a norm or extended to impaired discrimination, we tested children on a simultaneous match-to-sample task with the same stimuli. Both age groups were more accurate in judging the attractiveness of young faces relative to older faces; however, unlike adults, the young adult face bias extended to the match-to-sample task. These results suggest that by 3 years of age, children's perceptual system is more finely tuned for young adult faces than for older adult faces, which may support past findings of superior recognition for young adult faces.

Category-specific face prototypes are emerging, but not yet mature, in 5-year-old children

Adults' expertise in face recognition has been attributed to norm-based coding. Moreover, adults possess separable norms for a variety of face categories (e.g., race, sex, age) that appear to enhance recognition by reducing redundancy in the information shared by faces and ensuring that only relevant dimensions are used to encode faces from a given category. Although 5-year-old children process own-race faces using norm-based coding, little is known about the organization and refinement of their face space. The current study investigated whether 5-year-olds rely on category-specific norms and whether experience facilitates the development of dissociable face prototypes. In Experiment 1, we examined whether Chinese 5-year-olds show race-contingent opposing aftereffects and the extent to which aftereffects transfer across face race among Caucasian and Chinese 5-year-olds. Both participant races showed partial transfer of aftereffects across face race; however, there was no evidence for race-contingent opposing aftereffects. To examine whether experience facilitates the development of category-specific prototypes, we investigated whether race-contingent aftereffects are present among Caucasian 5-year-olds with abundant exposure to Chinese faces (Experiment 2) and then tested separate groups of 5-year-olds with two other categories with which they have considerable experience: sex (male/female faces) and age (adult/child faces) (Experiment 3). Across all three categories, 5-year-olds showed no category-contingent opposing aftereffects. These results demonstrate that 5 years of age is a stage characterized by minimal separation in the norms and associated coding dimensions used for faces from different categories and suggest that refinement of the mechanisms that underlie expert face processing occurs throughout childhood.

The influence of averageness on judgments of facial attractiveness: no own-age or own-sex advantage among children attending single-sex schools

We examined how recent biased face experience affects the influence of averageness on judgments of facial attractiveness among 8- and 9-year-old children attending a girls' school, a boys' school, and a mixed-sex school. We presented pairs of individual faces in which one face was transformed 50% toward its group average, whereas the other face was transformed 50% away from that average. Across blocks, the faces varied in age (adult, 9-year-old, or 5-year-old) and sex (male or female). We expected that averageness might influence attractiveness judgments more strongly for same-age faces and, for children attending single-sex schools, same-sex faces of that age because their prototype(s) should be best tuned to the faces they see most frequently. Averageness influenced children's judgments of attractiveness, but the strength of the influence was not modulated by the age of the face, nor did the effects of sex of face differ across schools. Recent biased experience might not have affected the results because of similarities between the average faces of different ages and sexes and/or because a minimum level of experience with a particular group of faces may be adequate for the formation of a veridical prototype and its influence on judgments of attractiveness. The results suggest that averageness affects children's judgments of the attractiveness of the faces they encounter in everyday life regardless of age or sex of face.

The influence of symmetry on children's judgments of facial attractiveness

In experiment 1, we examined developmental changes in the influence of symmetry on judgments of attractiveness by showing adults and children pairs of individual faces in which one face was transformed 75% toward perfect symmetry, while the other face was transformed by exaggerating its asymmetries by 75%. Adults and 9-year-olds, but not 5-year-olds, rated the more symmetric faces as more attractive than the less symmetric faces, although the effect was stronger in adults than 9-year-olds. The preference for symmetry was stronger for male than female faces, and stronger for adults' than children's faces. In experiment 2, comparisons of the symmetry of the original male and female faces revealed no measured differences but lower ratings by adults of symmetry in the male faces. Overall, the results suggest that the influence of symmetry on attractiveness judgments emerges after the age of 5 years, and matures after the age of 9 years. The stronger effects for adult viewers may reflect an increase in sensitivity to symmetry as experience with faces increases and/or as the visual system matures. As well, attractiveness may become more salient after puberty, so that honest signals of mate quality, such as symmetry, have a stronger effect for adult viewers, especially when judging adult faces.

Face adaptation effects: reviewing the impact of adapting information, time, and transfer

The ability to adapt is essential to live and survive in an ever-changing environment such as the human ecosystem. Here we review the literature on adaptation effects of face stimuli to give an overview of existing findings in this area, highlight gaps in its research literature, initiate new directions in face adaptation research, and help to design future adaptation studies. Furthermore, this review should lead to better understanding of the processing characteristics as well as the mental representations of face-relevant information. The review systematizes studies at a behavioral level in respect of a framework which includes three dimensions representing the major characteristics of studies in this field of research. These dimensions comprise (1) the specificity of adapting face information, e.g., identity, gender, or age aspects of the material to be adapted to (2) aspects of timing (e.g., the sustainability of adaptation effects) and (3) transfer relations between face images presented during adaptation and adaptation tests (e.g., images of the same or different identities). The review concludes with options for how to combine findings across different dimensions to demonstrate the relevance of our framework for future studies.

The neural correlates of the face attractiveness aftereffect: a functional near-infrared spectroscopy (fNIRS) study

Extensive behavioral evidence shows that our internal representation of faces, or face prototype, can be dynamically updated by immediate experience. This is illustrated by the robust attractiveness aftereffect phenomenon whereby originally unattractive faces become attractive after we are exposed to a set of unattractive faces. Although behavioral evidence suggests this effect to have a strong neural basis, limited neuroimaging evidence exists. Here we used functional near-infrared spectroscopy methodology (fNIRS) to bridge this gap. During the pre-adaptation trials, participants judged the attractiveness of three sets of faces: normal/undistorted faces, compressed faces (the internal features and distances between them were compressed), and expanded faces (the internal features and distances between them were stretched). Then, participants were shown extremely compressed faces for 5 min as adaptation stimuli, after which participants judged the same three sets of faces in post-adaptation trials. Behaviorally, after the adaptation trials, participants rated the compressed faces more attractive whereas they judged the other two sets of faces as less attractive, replicating the robust adaptation effect. fNIRS results showed that short-term exposure to compressed faces led to significant decreases in neural activity to all face types, but in a more extended network of cortical regions in the frontal and occipital cortexes for undistorted faces. Taken together, these findings suggest that the face attractiveness aftereffect mainly reflects changes in the neural representation of the face prototype in response to recent exposures to new face exemplars.

A critical review of the development of face recognition: experience is less important than previously believed

Historically, it has been argued that face individuation develops very slowly, not reaching adult levels until adolescence, with experience being the driving force behind this protracted improvement. Here, we challenge this view based on extensive review of behavioural and neural findings. Results demonstrate qualitative presence of all key phenomena related to face individuation (encoding of novel faces, holistic processing effects, face-space effects, face-selective responses in neuroimaging) at the earliest ages tested, typically 3-5 years of age and in many cases even infancy. Results further argue for quantitative maturity by early childhood, based on an increasing number of behavioural studies that have avoided the common methodological problem of restriction of range, as well as event-related potential (ERP), but not functional magnetic resonance imaging (fMRI) studies. We raise a new possibility that could account for the discrepant fMRI findings-namely, the use of adult-sized head coils on child-sized heads. We review genetic and innate contributions to face individuation (twin studies, neonates, visually deprived monkeys, critical periods, perceptual narrowing). We conclude that the role of experience in the development of the mechanisms of face identification has been overestimated. The emerging picture is that the mechanisms supporting face individuation are mature early, consistent with the social needs of children for reliable person identification in everyday life, and are also driven to an important extent by our evolutionary history.

SHIFTING THE PROTOTYPE: EXPERIENCE WITH FACES INFLUENCES AFFECTIVE AND ATTRACTIVENESS PREFERENCES

While some researchers have suggested that preferences for attractive faces are the result of a domain-specific beauty detection module, others argue these preferences develop based on averages of stimuli through a domain-general learning mechanism. We tested whether cognitive and perceptual mechanisms sensitive to experience underlie facial preferences by familiarizing participants with human, chimpanzee, or morphed faces (60%-chimp/40%-human). Results indicated that participants familiarized with human-chimp morphs showed greater zygomaticus major activity, a physiological correlate of positive affect (Study 1), and higher explicit attractiveness ratings (Study 2) to faces morphed to some degree with chimpanzees. These results demonstrate that experience shifts attractiveness preferences away from the normative average, and suggest that a domain-general cognitive mechanism better accounts for facial preferences than a domain-specific innate beauty-detector.