Multiple images captured from a single encounter do not promote face learning.

Viewing multiple images of a newly encountered face improves recognition of that identity in new instances. Studies examining face learning have presented high-variability (HV) images that incorporate changes that occur from moment-to-moment (e.g., head orientation and expression) and over time (e.g., lighting, hairstyle, and health). We examined whether low-variability (LV) images (i.e., images that incorporate only moment-to-moment changes) also promote generalisation of learning such that novel instances are recognised. Participants viewed a single image, six LV images, or six HV images of a target identity before being asked to recognise novel images of that identity in a face matching task (training stimuli remained visible) or a memory task (training stimuli were removed). In Experiment 1 (n = 71), participants indicated which image(s) in 8-image arrays belonged to the target identity. In Experiment 2 (n = 73), participants indicated whether sequentially presented images belonged to the target identity. Relative to the single-image condition, sensitivity to identity improved and response biases were less conservative in the HV condition; we found no evidence of generalisation of learning in the LV condition regardless of testing protocol. Our findings suggest that day-to-day variability in appearance plays an essential role in acquiring expertise with a novel face.

Ensemble coding of facial identity is robust, but may not contribute to face learning.

Ensemble coding - the rapid extraction of a perceptual average - has been proposed as a potential mechanism underlying face learning. We tested this proposal across five pre-registered experiments in which four ambient images of an identity were presented in the study phase. In Experiments 1 and 2a-c, participants were asked whether a test image was in the study array; these experiments examined the robustness of ensemble coding. Experiment 1 replicated ensemble coding in an online sample; participants recognize images from the study array and the average of those images. Experiments 2a-c provide evidence that ensemble coding meets several criteria of a possible learning mechanism: It is robust to changes in head orientation (± 60o), survives a short (30s) delay, and persists when images of two identities are interleaved during the study phase. Experiment 3 examined whether ensemble coding is sufficient for face learning (i.e., facilitates recognition of novel images of a target identity). Each study array comprised four ambient images (variability + average), a single image, or an average of four images (average only). Participants were asked whether a novel test image showed the identity from a study array. Performance was best in the four-image condition, with no difference between the single-image and average-only conditions. We conclude that ensemble coding of facial identity is robust but that the perceptual average per se is not sufficient for face learning.

Unfamiliar face matching ability predicts the slope of face learning.

We provide the first examination of individual differences in the efficiency of face learning. Investigating individual differences in face learning can illuminate potential mechanisms and provide greater understanding of why certain individuals might be more efficient face learners. Participants completed two unfamiliar face matching tasks and a learning task in which learning was assessed after viewing 1, 3, 6, and 9 images of to-be-learned identities. Individual differences in the slope of face learning (i.e., increases in sensitivity to identity) were predicted by the ability to discriminate between matched (same-identity) vs. mismatched (different-identity) pairs of wholly unfamiliar faces. A Dual Process Signal Detection model showed that three parameters increased with learning: Familiarity (an unconscious type of memory that varies in strength), recollection-old (conscious recognition of a learned identity), and recollection-new (conscious/confident rejection of novel identities). Good (vs. poor) matchers had higher Recollection-Old scores throughout learning and showed a steeper increase in Recollection-New. We conclude that good matchers are better able to capitalize on exposure to within-person variability in appearance, an effect that is attributable to their conscious memory for both learned and novel faces. These results have applied implications and will inform contemporary and traditional models of face identification.

We need to move beyond rating scales, white faces and adult perceivers: Invited Commentary on Sutherland & Young (2022), understanding trait impressions from faces.

Sutherland and Young's perspective is a timely and rigorous examination of trait impressions based on facial cues. We propose three strtegies to further advance the field: incorporating natural language processing, including diverse facial stimuli, and re-interpreting developmental data.

Picture this: Photographers no better than controls for recognizing unfamiliar faces.

With the exception of super recognizers and forensic examiners, people make a surprising number of errors when deciding whether photographs of unfamiliar faces belong to the same person or different people. Training protocols designed to improve professionals' (e.g., passport officers) performance often include photography. We evaluated the influence of life-time photography experience on the ability to distinguish matched versus mismatched face pairs. Expert photographers were not more sensitive to identity than hobbyists or novices-despite specializing in human subjects; Hobbyists were more liberal (more same responses) than Experts. We conclude that photography experience is not a route to expertise.

Children's ability to recognize their parent's face improves with age.

Adults are experts at recognizing familiar faces across images that incorporate natural within-person variability in appearance (i.e., ambient images). Little is known about children's ability to do so. In the current study, we investigated whether 4- to 7-year-olds (n = 56) could recognize images of their own parent-a person with whom children have had abundant exposure in a variety of different contexts. Children were asked to identify images of their parent that were intermixed with images of other people. We included images of each parent taken both before and after their child was born to manipulate how close the images were to the child's own experience. When viewing before-birth images, 4- and 5-year-olds were less sensitive to identity than were older children; sensitivity did not differ when viewing images taken after the child was born. These findings suggest that with even the most familiar face, 4- and 5-year-olds have difficulty recognizing instances that go beyond their direct experience. We discuss two factors that may contribute to the prolonged development of familiar face recognition.

The dimensions underlying first impressions of older adult faces are similar, but not identical, for young and older adult perceivers.

First impressions based on facial cues have the potential to influence how older adults (OAs), a vulnerable population, are treated by others. The present study used a data-driven approach to examine dimensions underlying first impressions of OAs and whether those dimensions vary by perceiver age. In Experiment 1, young adult (YA) and OA participants provided unconstrained, written descriptions in response to OA faces. From these descriptors, 18 trait categories were identified that were similar, but not identical, across age groups. In Experiment 2, YA and OA participants rated OA faces on the trait words identified for their age group in Experiment 1. In separate principal components analyses, dimensions of sternness and confidence emerged for both groups. In Experiment 3, YA and OA participants rated these same faces on new words encompassing traits, emotion cues, and other appearance cues. Correlations between these ratings and factor scores showed that sternness is analogous to approachability for both age groups. Confidence is analogous to competence for both age groups and related to perceived age/health/attractiveness. Confidence was related to shyness for YAs but dominance for OAs. The current research has implications for a lifespan perspective on first impressions and informs functional accounts.

Multi-cultural cities reduce disadvantages in recognizing naturalistic images of other-race faces: evidence from a novel face learning task.

People often find it more difficult to recognize other- than own-race faces. This other-race effect is robust across numerous ethnic groups. Yet, it remains unclear how this effect changes in people who live in a multiracial environment, and in immigrants whose lifetime perceptual experience changes over time. In the present study, we developed a novel face recognition test that approximates face recognition in the real world. We tested five groups of White and East Asian adults (n = 120) living in racially homogeneous versus heterogeneous cities and East Asians who immigrated to a multiracial city between infancy and adulthood. Multiracial cities reduce the other-race effect. The magnitude of the other-race effect changes as a function of experience, mirroring the racial diversity in perceivers' living environment. Our study highlights the challenge of forming reliable face representations across naturalistic facial variability and suggests a facilitative role of multiracial environments in eliminating the other-race effect.

What happens to our representation of identity as familiar faces age? Evidence from priming and identity aftereffects.

Matching identity in images of unfamiliar faces is error prone, but we can easily recognize highly variable images of familiar faces - even images taken decades apart. Recent theoretical development based on computational modelling can account for how we recognize extremely variable instances of the same identity. We provide complementary behavioural data by examining older adults' representation of older celebrities who were also famous when young. In Experiment 1, participants completed a long-lag repetition priming task in which primes and test stimuli were the same age or different ages. In Experiment 2, participants completed an identity after effects task in which the adapting stimulus was an older or young photograph of one celebrity and the test stimulus was a morph between the adapting identity and a different celebrity; the adapting stimulus was the same age as the test stimulus on some trials (e.g., both old) or a different age (e.g., adapter young, test stimulus old). The magnitude of priming and identity after effects were not influenced by whether the prime and adapting stimulus were the same age or different age as the test face. Collectively, our findings suggest that humans have one common mental representation for a familiar face (e.g., Paul McCartney) that incorporates visual changes across decades, rather than multiple age-specific representations. These findings make novel predictions for state-of-the-art algorithms (e.g., Deep Convolutional Neural Networks).

Recognizing, discriminating, and labeling emotional expressions in a free-sorting task: A developmental story.

Recognizing emotional expressions across different people and discriminating between them are important social skills. We examined their development using a novel free-sorting task in which children (aged 5 to 10) and adults sorted 20 faces (posing sadness, anger, fear, and disgust) into piles such that all faces in each pile were feeling the same. Participants could make as many or few piles (emotion categories) as they liked and then labeled each pile. There were no age-related changes in the number of piles made. Children made more confusion errors (two emotions in the same pile) than adults, a pattern that decreased with age. Errors were not random, but disproportionately involved placing fearful faces into piles labeled sad and disgusted faces into piles labeled angry-especially among children who did not produce fear and disgust labels, respectively. Our findings are consistent with differentiation and constructivist models of the development of emotion perception. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Learning faces from variability: Four- and five-year-olds differ from older children and adults.

Children under 6 years of age have difficulty recognizing a familiar face across changes in appearance and telling the face apart from similar-looking people. Understanding the process by which newly encountered faces become familiar can provide insights into these difficulties. Exposure to the ways in which a person varies in appearance is one mechanism by which adults and older children (≥6 years) learn new faces. We provide the first investigation of whether this mechanism for face learning functions in younger children. Children aged 4 and 5 years were read two storybooks featuring an unfamiliar character. Participants viewed six images of the character in one story and one image of the character in the other story. After each story, children were asked to identify novel images of the character that were intermixed with images of a similar-looking distractor. Like older children, 4- and 5-year-olds were more sensitive to identity in the 6-image condition, but they also adapted a less conservative criterion. Young children identified more images of the character after viewing six images versus one image. However, many also incorrectly identified more images of the distractor after viewing six images versus one image, an effect not previously found for older children and adults. These results suggest that this mechanism for face learning is not fully refined before 6 years of age.

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.

First impressions of child faces: Facial trustworthiness influences adults' interpretations of children's behavior in ambiguous situations.

Despite the profound behavioral consequences that first impressions of trustworthiness have on adult populations, few studies have examined how adults' first impressions of trustworthiness influence behavioral outcomes for children. Using a novel task design, we examined adults' perceptions of children's behavior in ambiguous situations. After a brief presentation of a child's face (high trust or low trust), participants viewed the child's face embedded within an ambiguous scene involving two children (Scene Task) or read a vignette about a misbehavior done by that child (Misbehavior Task). In the Scene Task, participants described what they believed to be happening in each scene; in the Misbehavior Task, participants indicated whether the behavior was done on purpose or by accident. In both tasks, participants also rated the behavior of the target child and indicated whether that child would be a good friend. In Experiment 1, young adults (n = 61) and older adults (n = 57) viewed unaltered face images. In Experiment 2, young adults (N = 59) completed the same tasks while viewing images of child faces morphed toward high-trust and low-trust averages. In both experiments, ambiguous scenes and misbehaviors were interpreted more positively when the target child had a high-trust face versus a low-trust face, with comparable patterns of results for the two age groups. Collectively, our results demonstrate that a child's facial trustworthiness biases how adults interpret children's behavior-a heuristic that may have lasting behavioral consequences for children through a self-fulfilling prophecy.

Ensemble coding of facial identity is not refined by experience: Evidence from other-race and inverted faces.

The ability to recognize identity despite within-person variability in appearance is likely a face-specific skill and shaped by experience. Ensemble coding - the automatic extraction of the average of a stimulus array - has been proposed as a mechanism underlying face learning (allowing one to recognize novel instances of a newly learned face). We investigated whether ensemble encoding, like face learning and recognition, is refined by experience by testing participants with upright own-race faces and two categories of faces with which they lacked experience: other-race faces (Experiment 1) and inverted faces (Experiment 2). Participants viewed four images of an unfamiliar identity and then were asked whether a test image of that same identity had been in the study array. Each test image was a matching exemplar (from the array), matching average (the average of the images in the array), non-matching exemplar (a novel image of the same identity), or non-matching average (an average of four different images of the same identity). Adults showed comparable ensemble coding for all three categories (i.e., reported that matching averages had been present more than non-matching averages), providing evidence that this early stage of face learning is not shaped by face-specific experience.

Interactive situations reveal more about children's emotional knowledge.

Research examining children's emotion judgments has generally used nonsocial tasks that do not resemble children's daily experiences in judging others' emotions. Here, younger children (4- to 6-year-olds) and older children (7- to 9-year-olds) participated in a socially interactive task where an experimenter opened boxes and made an expression (happy, sad, scared, or disgust) based on the object inside. Children guessed which of four objects (a sticker, a broken toy car, a spider, or toy poop) was in the box. Subsequently, children opened a set of boxes and generated facial expressions for the experimenter. Children also labeled the emotion elicited by the objects and static facial expressions. Children's ability to guess which object caused the experimenter's expression increased with age but did not predict their ability to generate a recognizable expression. Children's demonstration of emotion knowledge also varied across tasks, suggesting that when emotion judgment tasks more closely mimic their daily experiences, children demonstrate broader emotion knowledge.

Visual configural processing in adults born at extremely low birth weight.

Being born at extremely low birth weight (ELBW; ≤1,000 g) is associated with enduring visual impairments. We tested for long-term, higher order visual processing problems in the oldest known prospectively followed cohort of ELBW survivors. Configural processing (spacing among features of an object) was examined in 62 adults born at ELBW (Mage  = 31.9 years) and 82 adults born at normal birth weight (NBW; ≥2,500 g: Mage  = 32.5 years). Pairs of human faces, monkey faces, or houses were presented in a delayed match-to-sample task, where non-matching stimuli differed only in the spacing of their features. Discrimination accuracy for each stimulus type was compared between birth weight groups, adjusting for neurosensory impairment, visual acuity, binocular fusion ability, IQ, and sex. Both groups were better able to discriminate human faces than monkey faces (p < .001). However, the ELBW group discriminated between human faces (p < .001), between monkey faces (p < .001), and to some degree, between houses (p < .06), more poorly than NBW control participants, suggesting a general deficit in perceptual processing. Human face discrimination was related to performance IQ (PIQ) across groups, but especially among ELBW survivors. Coding (a PIQ subtest) also predicted human face discrimination in ELBW survivors, consistent with previously reported links between visuo-perceptive difficulties and regional slowing of cortical activity in individuals born preterm. Correlations with Coding suggested ELBW survivors may have used a feature-matching approach to processing human faces. Future studies could examine brain-based anatomical and functional evidence for altered face processing, as well as the social and memory consequences of face-processing deficits in ELBW survivors.

Children's perception of emotions in the context of live interactions: Eye movements and emotion judgements.

Research examining children's understanding of emotional expressions has generally used static, isolated facial expressions presented in a non-interactive context. However, these tasks do not resemble children's experiences with expressions in daily life, where they must attend to a range of information, including others' facial expressions, movements, and the situation surrounding the expression. In this research, we examine the development of visual attention to another's emotional expressions during a live interaction. Via an eye-tracker, children (4-11 years old) and adults viewed an experimenter open a series of opaque boxes and make an expression (happiness, sadness, fear, or disgust) based on the object inside. Participants determined which of four possible objects (stickers, a broken toy, a spider, or dog poop) was in the box. We examined the proportion of the trial in which participants looked to three areas of the face (the eyes, mouth, and nose area), and the available contextual information (the box held by the experimenter, the four objects). Although children spent less time looking to the face than adults did, their pattern of visual attention within the face and to object AOIs did not differ from that of adults. Finally, for adults, increased accuracy was linked to spending less time looking to the objects whereas increased accuracy for children was not strongly linked to any emotion cue. These data indicate that although children spend less time looking to the face during live interactions than adults do, the proportion of time spent looking to areas of the face and context are generally adult-like.

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.

Attending to identity cues reduces the own-age but not the own-race recognition advantage.

Adults' ability to recognize individual faces is shaped by experience. Young adults recognize own-age and own-race faces more accurately than other-age and other-race faces. The own-age and own-race biases have been attributed to differential perceptual experience and to differences in how in-group vs. out-group faces are processed, with in-group faces being processed at the individual level and out-group faces being processed at the categorical level. To examine this social categorization hypothesis, young adults studied young and older faces in Experiment 1 and own- and other-race faces in Experiment 2. During the learning phase the identity-matching group viewed faces in pairs and completed a same/different task designed to enhance attention to individuating cues; the passive-viewing group memorized faces presented individually. After the learning phase, all participants completed an identical old/new recognition task. Both passive-viewing groups showed the expected recognition bias, but divergent patterns were observed in the identity-matching groups. Whereas the identity-matching task eliminated the own-age bias, it neither eliminated nor reduced the own-race bias. Collectively, these results suggest that categorization-individuation processes do not play the same role in explaining the two recognition biases.

No experimental evidence for emotion-specific gaze cueing in a threat context.

We examined the utility of a gaze cueing paradigm to examine sensitivity to differences among negatively valenced expressions. Participants judged target stimuli (dangerous or safe), the location of which was cued by the gaze direction of a central face. Dawel et al. reported that gaze cueing effects (faster response times on valid vs. invalid trials) were larger when the central face displayed fear than when it displayed happiness. Our aim was to determine whether this effect was specific to fear, to all threat-related expressions (fear, anger), or to all negatively valenced expressions (fear, anger, sadness, disgust) with the aim of using this protocol to study the development of implicit discrimination of negatively valenced expressions. Across five experiments in which we varied the number of models (1 vs. 4), the number of expressions (2 vs. 5), and the country of residence of participants (Canada vs. Australia) we found no evidence that the magnitude of gaze cueing effects is modulated by expression. We discuss our failure to replicate in the context of the broader literature.