The Faces in Infant-Perspective Scenes Change over the First Year of Life

Incorporating simulated spatial context information improves the effectiveness of contrastive learning models

Visual learning often occurs in a specific context, where an agent acquires skills through exploration and tracking of its location in a consistent environment. The historical spatial context of the agent provides a similarity signal for self-supervised contrastive learning. We present a unique approach, termed environmental spatial similarity (ESS), that complements existing contrastive learning methods. Using images from simulated, photorealistic environments as an experimental setting, we demonstrate that ESS outperforms traditional instance discrimination approaches. Moreover, sampling additional data from the same environment substantially improves accuracy and provides new augmentations. ESS allows remarkable proficiency in room classification and spatial prediction tasks, especially in unfamiliar environments. This learning paradigm has the potential to enable rapid visual learning in agents operating in new environments with unique visual characteristics. Potentially transformative applications span from robotics to space exploration. Our proof of concept demonstrates improved efficiency over methods that rely on extensive, disconnected datasets.

Caregiving relationships are a cornerstone of developmental psychopathology

The interdisciplinary field of developmental psychopathology has made great strides by including context into theoretical and empirical approaches to studying risk and resilience. Perhaps no context is more important to the developing child than their relationships with their caregivers (typically a child's parents), as caregivers are a key source of stimulation and nurturance to young children. Coupled with the high degree of brain plasticity in the earliest years of life, these caregiving relationships have an immense influence on shaping behavioral outcomes relevant to developmental psychopathology. In this article, we discuss three areas within caregiving relationships: (1) caregiver-child interactions in everyday, naturalistic settings; (2) caregivers' social cognitions about their child; and (3) caregivers' broader social and cultural context. For each area, we provide an overview of its significance to the field, identify existing knowledge gaps, and offer potential approaches for bridging these gaps to foster growth in the field. Lastly, given that one value of a scientific discipline is its ability to produce research useful in guiding real-world decisions related to policy and practice, we encourage developmental psychopathology to consider that a focus on caregiving, a modifiable target, supports this mission.

Moving beyond "nouns in the lab": Using naturalistic data to understand why infants' first words include uh-oh and hi

Why do infants learn some words earlier than others? Many theories of early word learning focus on explaining how infants map labels onto concrete objects. However, words that are more abstract than object nouns, such as uh-oh, hi, more, up, and all-gone, are typically among the first to appear in infants' vocabularies. We combined a behavioral experiment with naturalistic observational research to explore how infants learn and represent this understudied category of high-frequency, routine-based non-nouns, which we term "everyday words." In Study 1, we found that a conventional eye-tracking measure of comprehension was insufficient to capture U.S.-based English-learning 10- to 16-month-old infants' emerging understanding of everyday words. In Study 2, we analyzed the visual and social scenes surrounding caregivers' and infants' use of everyday words in a naturalistic video corpus. This ecologically motivated research revealed that everyday words rarely co-occurred with consistent visual referents, making their early learnability difficult to reconcile with dominant word learning theories. Our findings instead point to complex patterns in the types of situations associated with everyday words that could contribute to their early representation in infants' vocabularies. By leveraging both experimental and observational methods, this investigation underscores the value of using naturalistic data to broaden theories of early learning. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Are people with autism prosopagnosic?

Difficulties in various face processing tasks have been well documented in autism spectrum disorder (ASD). Several meta-analyses and numerous case-control studies have indicated that this population experiences a moderate degree of impairment, with a small percentage of studies failing to detect any impairment. One possible account of this mixed pattern of findings is heterogeneity in face processing abilities stemming from the presence of a subpopulation of prosopagnosic individuals with ASD alongside those with normal face processing skills. Samples randomly drawn from such a population, especially relatively smaller ones, would vary in the proportion of participants with prosopagnosia, resulting in a wide range of group-level deficits from mild (or none) to severe across studies. We test this prosopagnosic subpopulation hypothesis by examining three groups of participants: adults with ASD, adults with developmental prosopagnosia (DP), and a comparison group. Our results show that the prosopagnosic subpopulation hypothesis does not account for the face impairments in the broader autism spectrum. ASD observers show a continuous and graded, rather than categorical, heterogeneity that span a range of face processing skills including many with mild to moderate deficits, inconsistent with a prosopagnosic subtype account. We suggest that pathogenic origins of face deficits for at least some with ASD differ from those of DP.

The Role of Talking Faces in Infant Language Learning: Mind the Gap between Screen-Based Settings and Real-Life Communicative Interactions

Over the last few decades, developmental (psycho) linguists have demonstrated that perceiving talking faces audio-visually is important for early language acquisition. Using mostly well-controlled and screen-based laboratory approaches, this line of research has shown that paying attention to talking faces is likely to be one of the powerful strategies infants use to learn their native(s) language(s). In this review, we combine evidence from these screen-based studies with another line of research that has studied how infants learn novel words and deploy their visual attention during naturalistic play. In our view, this is an important step toward developing an integrated account of how infants effectively extract audiovisual information from talkers' faces during early language learning. We identify three factors that have been understudied so far, despite the fact that they are likely to have an important impact on how infants deploy their attention (or not) toward talking faces during social interactions: social contingency, speaker characteristics, and task- dependencies. Last, we propose ideas to address these issues in future research, with the aim of reducing the existing knowledge gap between current experimental studies and the many ways infants can and do effectively rely upon the audiovisual information extracted from talking faces in their real-life language environment.

Deep learning models challenge the prevailing assumption that face-like effects for objects of expertise support domain-general mechanisms

The question of whether task performance is best achieved by domain-specific, or domain-general processing mechanisms is fundemental for both artificial and biological systems. This question has generated a fierce debate in the study of expert object recognition. Because humans are experts in face recognition, face-like neural and cognitive effects for objects of expertise were considered support for domain-general mechanisms. However, effects of domain, experience and level of categorization, are confounded in human studies, which may lead to erroneous inferences. To overcome these limitations, we trained deep learning algorithms on different domains (objects, faces, birds) and levels of categorization (basic, sub-ordinate, individual), matched for amount of experience. Like humans, the models generated a larger inversion effect for faces than for objects. Importantly, a face-like inversion effect was found for individual-based categorization of non-faces (birds) but only in a network specialized for that domain. Thus, contrary to prevalent assumptions, face-like effects for objects of expertise do not support domain-general mechanisms but may originate from domain-specific mechanisms. More generally, we show how deep learning algorithms can be used to dissociate factors that are inherently confounded in the natural environment of biological organisms to test hypotheses about their isolated contributions to cognition and behaviour.

Not all is forgotten: Children's associative matrices for features of a word learning episode

Word learning studies traditionally examine the narrow link between words and objects, indifferent to the rich contextual information surrounding objects. This research examined whether children attend to this contextual information and construct an associative matrix of the words, objects, people, and environmental context during word learning. In Experiment 1, preschool-aged children (age: 3;2-5;11 years) were presented with novel words and objects in an animated storybook. Results revealed that children constructed associations beyond words and objects. Specifically, children attended to and had the strongest associations for features of the environmental context but failed to learn word-object associations. Experiment 2 demonstrated that children (age: 3;0-5;8 years) leveraged strong associations for the person and environmental context to support word-object mapping. This work demonstrates that children are especially sensitive to the word learning context and use associative matrices to support word mapping. Indeed, this research suggests associative matrices of the environment may be foundational for children's vocabulary development.

Looking at faces in the wild

Faces are key to everyday social interactions, but our understanding of social attention is based on experiments that present images of faces on computer screens. Advances in wearable eye-tracking devices now enable studies in unconstrained natural settings but this approach has been limited by manual coding of fixations. Here we introduce an automatic 'dynamic region of interest' approach that registers eye-fixations to bodies and faces seen while a participant moves through the environment. We show that just 14% of fixations are to faces of passersby, contrasting with prior screen-based studies that suggest faces automatically capture visual attention. We also demonstrate the potential for this new tool to help understand differences in individuals' social attention, and the content of their perceptual exposure to other people. Together, this can form the basis of a new paradigm for studying social attention 'in the wild' that opens new avenues for theoretical, applied and clinical research.

Development of upper visual field bias for faces in infants

The spatial location of the face and body seen in daily life influences human perception and recognition. This contextual effect of spatial locations suggests that daily experience affects how humans visually process the face and body. However, it remains unclear whether this effect is caused by experience, or innate neural pathways. To address this issue, we examined the development of visual field asymmetry for face processing, in which faces in the upper visual field were processed preferentially compared to the lower visual field. We found that a developmental change occurred between 6 and 7 months. Older infants aged 7-8 months showed bias toward faces in the upper visual field, similar to adults, but younger infants of 5-6 months showed no such visual field bias. Furthermore, older infants preferentially memorized faces in the upper visual field, rather than in the lower visual field. These results suggest that visual field asymmetry is acquired through development, and might be caused by the learning of spatial location in daily experience.

Maternal attitudes and behaviours differentially shape infant early life experience: A cross cultural study

Early life environments afford infants a variety of learning opportunities, and caregivers play a fundamental role in shaping infant early life experience. Variation in maternal attitudes and parenting practices is likely to be greater between than within cultures. However, there is limited cross-cultural work characterising how early life environment differs across populations. We examined the early life environment of infants from two cultural contexts where attitudes towards parenting and infant development were expected to differ: in a group of 53 mother-infant dyads in the UK and 44 mother-infant dyads in Uganda. Participants were studied longitudinally from when infants were 3- to 15-months-old. Questionnaire data revealed the Ugandan mothers had more relational attitudes towards parenting than the mothers from the UK, who had more autonomous parenting attitudes. Using questionnaires and observational methods, we examined whether infant development and experience aligned with maternal attitudes. We found the Ugandan infants experienced a more relational upbringing than the UK infants, with Ugandan infants receiving more distributed caregiving, more body contact with their mothers, and more proximity to mothers at night. Ugandan infants also showed earlier physical development compared to UK infants. Contrary to our expectations, however, Ugandan infants were not in closer proximity to their mothers during the day, did not have more people in proximity or more partners for social interaction compared to UK infants. In addition, when we examined attitudes towards specific behaviours, mothers' attitudes rarely predicted infant experience in related contexts. Taken together our findings highlight the importance of measuring behaviour, rather than extrapolating expected behaviour based on attitudes alone. We found infants' early life environment varies cross-culturally in many important ways and future research should investigate the consequences of these differences for later development.

Anatomical correlates of category-selective visual regions have distinctive signatures of connectivity in neonates

The ventral visual stream is shaped during development by innate proto-organization within the visual system, such as the strong input from the fovea to the fusiform face area. In adults, category-selective regions have distinct signatures of connectivity to brain regions beyond the visual system, likely reflecting cross-modal and motoric associations. We tested if this long-range connectivity is part of the innate proto-organization, or if it develops with postnatal experience, by using diffusion-weighted imaging to characterize the connectivity of anatomical correlates of category-selective regions in neonates (N = 445), 1-9 month old infants (N = 11), and adults (N = 14). Using the HCP data we identified face- and place- selective regions and a third intermediate region with a distinct profile of selectivity. Using linear classifiers, these regions were found to have distinctive connectivity at birth, to other regions in the visual system and to those outside of it. The results support an extended proto-organization that includes long-range connectivity that shapes, and is shaped by, experience-dependent development.

Face-to-face contact during infancy: How the development of gaze to faces feeds into infants' vocabulary outcomes

Infants acquire their first words through interactions with social partners. In the first year of life, infants receive a high frequency of visual and auditory input from faces, making faces a potential strong social cue in facilitating word-to-world mappings. In this position paper, we review how and when infant gaze to faces is likely to support their subsequent vocabulary outcomes. We assess the relevance of infant gaze to faces selectively, in three domains: infant gaze to different features within a face (that is, eyes and mouth); then to faces (compared to objects); and finally to more socially relevant types of faces. We argue that infant gaze to faces could scaffold vocabulary construction, but its relevance may be impacted by the developmental level of the infant and the type of task with which they are presented. Gaze to faces proves relevant to vocabulary, as gazes to eyes could inform about the communicative nature of the situation or about the labeled object, while gazes to the mouth could improve word processing, all of which are key cues to highlighting word-to-world pairings. We also discover gaps in the literature regarding how infants' gazes to faces (versus objects) or to different types of faces relate to vocabulary outcomes. An important direction for future research will be to fill these gaps to better understand the social factors that influence infant vocabulary outcomes.

Eye contact avoidance in crowds: A large wearable eye-tracking study

Eye contact is essential for human interactions. We investigated whether humans are able to avoid eye contact while navigating crowds. At a science festival, we fitted 62 participants with a wearable eye tracker and instructed them to walk a route. Half of the participants were further instructed to avoid eye contact. We report that humans can flexibly allocate their gaze while navigating crowds and avoid eye contact primarily by orienting their head and eyes towards the floor. We discuss implications for crowd navigation and gaze behavior. In addition, we address a number of issues encountered in such field studies with regard to data quality, control of the environment, and participant adherence to instructions. We stress that methodological innovation and scientific progress are strongly interrelated.

Everyday Parameters for Episode-to-Episode Dynamics in the Daily Music of Infancy

Experience‐dependent change pervades early human development. Though trajectories of developmental change have been well charted in many domains, the episode‐to‐episode schedules of experiences on which they are hypothesized to depend have not. Here, we took up this issue in a domain known to be governed in part by early experiences: music. Using a corpus of longform audio recordings, we parameterized the daily schedules of music encountered by 35 infants ages 6–12 months. We discovered that everyday music episodes, as well as the interstices between episodes, typically persisted less than a minute, with most daily schedules also including some very extended episodes and interstices. We also discovered that infants encountered music episodes in a bursty rhythm, rather than a periodic or random rhythm, over the day. These findings join a suite of recent discoveries from everyday vision, motor, and language that expand our imaginations beyond artificial learning schedules and enable theorists to model the history‐dependence of developmental process in ways that respect everyday sensory histories. Future theories about how infants build knowledge across multiple episodes can now be parameterized using these insights from infants’ everyday lives.

Infants' sensitivity to emotional expressions in actions: The contributions of parental expressivity and motor experience

Actions can convey information about the affective state of an actor. By the end of the first year, infants show sensitivity to such emotional information in actions. Here, we examined the mechanisms contributing to infants' developing sensitivity to emotional action kinematics. We hypothesized that this sensitivity might rely on two factors: a stable motor representation of the observed action to be able to detect deviations from how it would typically be performed and experience with emotional expressions. The sensitivity of 12- to 13-month-old infants to happy and angry emotional cues in a manual transport action was examined using facial EMG. Infants' own movements when performing an object transport task were assessed using optical motion capture. The infants' caregivers' emotional expressivity was measured using a questionnaire. Negative emotional expressivity of the primary caregiver was significantly related to infants' sensitivity to observed angry actions. There was no evidence for such an association with infants' own motor skill. Overall, our results show that infants' experience with emotions, measured as caregivers' emotional expressivity, may aid infants' discrimination of others' emotions expressed in action kinematics.

Asymmetrical responding to male versus female other-race categories in 9- to 12-month-old infants

Faces can be categorized along various dimensions including gender or race, an ability developing in infancy. Infant categorization studies have focused on facial attributes in isolation, but the interaction between these attributes remains poorly understood. Experiment 1 examined gender categorization of other-race faces in 9- and 12-month-old White infants. Nine- and 12-month-olds were familiarized with Asian male or female faces, and tested with a novel exemplar from the familiarized category paired with a novel exemplar from a novel category. Both age groups showed novel category preferences for novel Asian female faces after familiarization with Asian male faces, but showed no novel category preference for novel Asian male faces after familiarization with Asian female faces. This categorization asymmetry was not due to a spontaneous preference hindering novel category reaction (Experiment 2), and both age groups displayed difficulty discriminating among male, but not female, other-race faces (Experiment 3). These results indicate that category formation for male other-race faces is mediated by categorical perception. Overall, the findings suggest that even by 12 months of age, infants are not fully able to form gender category representations of other-race faces, responding categorically to male, but not female, other-race faces.

Discourse with Few Words: Coherence Statistics, Parent-Infant Actions on Objects, and Object Names

The data for early object name learning is often conceptualized as a problem of mapping heard names to referents. However, infants do not hear object names as discrete events but rather in extended interactions organized around goal-directed actions on objects. The present study examined the statistical structure of the nonlinguistic events that surround parent naming of objects. Parents and 12-month -old infants were left alone in a room for 10 minutes with 32 objects available for exploration. Parent and infant handling of objects and parent naming of objects were coded. The four measured statistics were from measures used in the study of coherent discourse: (1) a frequency distribution in which actions were frequently directed to a few objects and more rarely to other objects; (2) repeated returns to the high-frequency objects over the 10-minute play period; (3) clustered repetitions, continuity, of actions on objects; and (4) structured networks of transitions among objects in play that connected all the played-with objects. Parent naming was infrequent but related to the statistics of object-directed actions. The implications of the discourse-like stream of actions are discussed in terms of learning mechanisms that could support rapid learning of object names from relatively few name-object co-occurrences.

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.

Infant sensitivity to age-based social categories in full-body displays

This study examined 3.5- and 6-month-old infants' visual preferences for individuals from different age groups: adults versus infants. Unlike previous studies that only studied faces, here we included bodies, which are as frequent as faces in our environment, and highly salient, and in consequence, may play a role in identifying social categories and driving social preferences. In particular, we studied three salient dimensions along which individuals of different ages differ: body length, body typology, and face typology. In Experiment 1, adult and infant stimuli were presented in real proportions, differing both in body length and face typology, and infants preferred the adult stimuli. Experiment 2 demonstrated that given identical adult stimuli, which differ only in body length, infants attended more to the longer stimuli. In Experiment 3, infant and adult stimuli were matched on body length with the infant stimuli having larger heads, and infants preferred the infant stimuli. Experiment 4 measured infant visual preference for infant or adult bodies in the absence of face information, and found that 4-month-olds attended more to the infant bodies. Experiment 5 measured infants' sensitivity to matching or mismatching faces and bodies based on age, and infants demonstrated a preference for the incongruent stimuli (i.e., adult head with an infant body). Altogether these studies show that while face typology and body size are main drivers of infant visual preference for adults, when body typology information is provided for bodies matched in size, infant preference shifts towards their peers. Thus, our results suggest that infants have early developing age-based body representations, and that body information shifts their pattern of visual behavior from a visual preference for adult faces, to a visual preference for full-body peers.

Brain-like functional specialization emerges spontaneously in deep neural networks

The human brain contains multiple regions with distinct, often highly specialized functions, from recognizing faces to understanding language to thinking about what others are thinking. However, it remains unclear why the cortex exhibits this high degree of functional specialization in the first place. Here, we consider the case of face perception using artificial neural networks to test the hypothesis that functional segregation of face recognition in the brain reflects a computational optimization for the broader problem of visual recognition of faces and other visual categories. We find that networks trained on object recognition perform poorly on face recognition and vice versa and that networks optimized for both tasks spontaneously segregate themselves into separate systems for faces and objects. We then show functional segregation to varying degrees for other visual categories, revealing a widespread tendency for optimization (without built-in task-specific inductive biases) to lead to functional specialization in machines and, we conjecture, also brains.

Beyond screen time: Using head-mounted eye tracking to study natural behavior

Head-mounted eye tracking is a new method that allows researchers to catch a glimpse of what infants and children see during naturalistic activities. In this chapter, we review how mobile, wearable eye trackers improve the construct validity of important developmental constructs, such as visual object experiences and social attention, in ways that would be impossible using screen-based eye tracking. Head-mounted eye tracking improves ecological validity by allowing researchers to present more realistic and complex visual scenes, create more interactive experimental situations, and examine how the body influences what infants and children see. As with any new method, there are difficulties to overcome. Accordingly, we identify what aspects of head-mounted eye-tracking study design affect the measurement quality, interpretability of the results, and efficiency of gathering data. Moreover, we provide a summary of best practices aimed at allowing researchers to make well-informed decisions about whether and how to apply head-mounted eye tracking to their own research questions.

Face Processing in Early Development: A Systematic Review of Behavioral Studies and Considerations in Times of COVID-19 Pandemic

Human faces are one of the most prominent stimuli in the visual environment of young infants and convey critical information for the development of social cognition. During the COVID-19 pandemic, mask wearing has become a common practice outside the home environment. With masks covering nose and mouth regions, the facial cues available to the infant are impoverished. The impact of these changes on development is unknown but is critical to debates around mask mandates in early childhood settings. As infants grow, they increasingly interact with a broader range of familiar and unfamiliar people outside the home; in these settings, mask wearing could possibly influence social development. In order to generate hypotheses about the effects of mask wearing on infant social development, in the present work, we systematically review N = 129 studies selected based on the most recent PRISMA guidelines providing a state-of-the-art framework of behavioral studies investigating face processing in early infancy. We focused on identifying sensitive periods during which being exposed to specific facial features or to the entire face configuration has been found to be important for the development of perceptive and socio-communicative skills. For perceptive skills, infants gradually learn to analyze the eyes or the gaze direction within the context of the entire face configuration. This contributes to identity recognition as well as emotional expression discrimination. For socio-communicative skills, direct gaze and emotional facial expressions are crucial for attention engagement while eye-gaze cuing is important for joint attention. Moreover, attention to the mouth is particularly relevant for speech learning. We discuss possible implications of the exposure to masked faces for developmental needs and functions. Providing groundwork for further research, we encourage the investigation of the consequences of mask wearing for infants' perceptive and socio-communicative development, suggesting new directions within the research field.

Ten lessons about infants' everyday experiences

Audio recorders, accelerometers, and cameras that infants wear throughout their everyday lives capture the experiences that are available to shape development. Everyday sensing in infancy reveals patterns within the everyday hubbub that are unknowable using methods that capture shorter, more isolated, or more planned slices of behavior. Here, we review ten lessons learned from recent endeavors that removed researchers from designing or participating in infants' experiences and instead quantified patterns that arose within infants' own spontaneously arising everyday experiences. The striking heterogeneity of experiences - there is no meaningfully "representative" hour of a day, instance of a category, interaction context, or infant - inspires next steps in theory and practice that embrace the complex, dynamic, and multiple pathways of human development.

Infants' visual exploration strategies for adult and child faces

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

The development of visual attention in infancy: A cascade approach

Visual attention develops rapidly and significantly during the first postnatal years. At birth, infants have poor visual acuity, poor head and neck control, and as a result have little autonomy over where and how long they look. Across the first year, the neural systems that support alerting, orienting, and endogenous attention develop, allowing infants to more effectively focus their attention on information in the environment important for processing. However, visual attention is a system that develops in the context of the whole child, and fully understanding this development requires understanding how attentional systems interact and how these systems interact with other systems across wide domains. By adopting a cascades framework we can better position the development of visual attention in the context of the whole developing child. Specifically, development builds, with previous achievements setting the stage for current development, and current development having cascading consequences on future development. In addition, development reflects changes in multiple domains, and those domains influence each other across development. Finally, development reflects and produces changes in the input that the visual system receives; understanding the changing input is key to fully understand the development of visual attention. The development of visual attention is described in this context.

Cortical processing of dynamic bodies in the superior occipito-temporal regions of the infants' brain: Difference from dynamic faces and inversion effect

Previous functional neuroimaging studies imply a crucial role of the superior temporal regions (e.g., superior temporal sulcus: STS) for processing of dynamic faces and bodies. However, little is known about the cortical processing of moving faces and bodies in infancy. The current study used functional near-infrared spectroscopy (fNIRS) to directly compare cortical hemodynamic responses to dynamic faces (videos of approaching people with blurred bodies) and dynamic bodies (videos of approaching people with blurred faces) in infants' brain. We also examined the body-inversion effect in 5- to 8-month-old infants using hemodynamic responses as a measure. We found significant brain activity for the dynamic faces and bodies in the superior area of bilateral temporal cortices in both 5- to 6-month-old and 7- to 8-month-old infants. The hemodynamic responses to dynamic faces occurred across a broader area of cortex in 7- to 8-month-olds than in 5- to 6-month-olds, but we did not find a developmental change for dynamic bodies. There was no significant activation when the stimuli were presented upside down, indicating that these activation patterns did not result from the low-level visual properties of dynamic faces and bodies. Additionally, we found that the superior temporal regions showed a body inversion effect in infants aged over 5 months: the upright dynamic body stimuli induced stronger activation compared to the inverted stimuli. The most important contribution of the present study is that we identified cortical areas responsive to dynamic bodies and faces in two groups of infants (5-6-months and 7-8-months of age) and we found different developmental trends for the processing of bodies and faces.

Quantifying Everyday Ecologies: Principles for Manual Annotation of Many Hours of Infants' Lives

Everyday experiences are the experiences available to shape developmental change. Remarkable advances in devices used to record infants' and toddlers' everyday experiences, as well as in repositories to aggregate and share such recordings across teams of theorists, have yielded a potential gold mine of insights to spur next-generation theories of experience-dependent change. Making full use of these advances, however, currently requires manual annotation. Manually annotating many hours of everyday life is a dedicated pursuit requiring significant time and resources, and in many domains is an endeavor currently lacking foundational facts to guide potentially consequential implementation decisions. These realities make manual annotation a frequent barrier to discoveries, as theorists instead opt for narrower scoped activities. Here, we provide theorists with a framework for manually annotating many hours of everyday life designed to reduce both theoretical and practical overwhelm. We share insights based on our team's recent adventures in the previously uncharted territory of everyday music. We identify principles, and share implementation examples and tools, to help theorists achieve scalable solutions to challenges that are especially fierce when annotating extended timescales. These principles for quantifying everyday ecologies will help theorists collectively maximize return on investment in databases of everyday recordings and will enable a broad community of scholars—across institutions, skillsets, experiences, and working environments—to make discoveries about the experiences upon which development may depend.

Face Recognition by Humans and Machines: Three Fundamental Advances from Deep Learning

Deep learning models currently achieve human levels of performance on real-world face recognition tasks. We review scientific progress in understanding human face processing using computational approaches based on deep learning. This review is organized around three fundamental advances. First, deep networks trained for face identification generate a representation that retains structured information about the face (e.g., identity, demographics, appearance, social traits, expression) and the input image (e.g., viewpoint, illumination). This forces us to rethink the universe of possible solutions to the problem of inverse optics in vision. Second, deep learning models indicate that high-level visual representations of faces cannot be understood in terms of interpretable features. This has implications for understanding neural tuning and population coding in the high-level visual cortex. Third, learning in deep networks is a multistep process that forces theoretical consideration of diverse categories of learning that can overlap, accumulate over time, and interact. Diverse learning types are needed to model the development of human face processing skills, cross-race effects, and familiarity with individual faces.

On the relationship between maps and domains in inferotemporal cortex

How does the brain encode information about the environment? Decades of research have led to the pervasive notion that the object-processing pathway in primate cortex consists of multiple areas that are each specialized to process different object categories (such as faces, bodies, hands, non-face objects and scenes). The anatomical consistency and modularity of these regions have been interpreted as evidence that these regions are innately specialized. Here, we propose that ventral-stream modules do not represent clusters of circuits that each evolved to process some specific object category particularly important for survival, but instead reflect the effects of experience on a domain-general architecture that evolved to be able to adapt, within a lifetime, to its particular environment. Furthermore, we propose that the mechanisms underlying the development of domains are both evolutionarily old and universal across cortex. Topographic maps are fundamental, governing the development of specializations across systems, providing a framework for brain organization.

Exploring emotional face processing in 5-month-olds: The relation with quality of parent-child interaction and spatial frequencies

It is unclear whether infants differentially process emotional faces in the brain at 5 months of age. Contradictory findings of previous research indicate that additional factors play a role in this process. The current study investigated whether five-month-old infants show differential brain activity between emotional faces. Furthermore, we explored the relation between emotional face processing and (I) stimulus characteristics, specifically the spatial frequency content, and (II) parent, child, and dyadic qualities of interaction characteristics. Face-sensitive components (i.e., N290, P400, Nc) in response to neutral and fearful faces that contained only lower or higher spatial frequencies were assessed. Quality of parent-child interaction was assessed with the Manchester Assessment of Caregiver Infant Interaction (MACI). The results show that, as a full group, none of the components differed between emotional expressions. However, when splitting the group based on median MACI scores, infants who showed high quality of interaction (i.e., more attentiveness to caregiver, positive and negative affect, and liveliness) processed emotions differently, whereas infants who showed low quality did not. These results indicate that a sub-group of infants show differential emotional face processing at 5 months of age, which seem to relate to quality of their behavior during the parent-child interaction.

Everyday music in infancy

Infants enculturate to their soundscape over the first year of life, yet theories of how they do so rarely make contact with details about the sounds available in everyday life. Here, we report on properties of a ubiquitous early ecology in which foundational skills get built: music. We captured daylong recordings from 35 infants ages 6–12 months at home and fully double‐coded 467 h of everyday sounds for music and its features, tunes, and voices. Analyses of this first‐of‐its‐kind corpus revealed two distributional properties of infants’ everyday musical ecology. First, infants encountered vocal music in over half, and instrumental in over three‐quarters, of everyday music. Live sources generated one‐third, and recorded sources three‐quarters, of everyday music. Second, infants did not encounter each individual tune and voice in their day equally often. Instead, the most available identity cumulated to many more seconds of the day than would be expected under a uniform distribution. These properties of everyday music in human infancy are different from what is discoverable in environments highly constrained by context (e.g., laboratories) and time (e.g., minutes rather than hours). Together with recent insights about the everyday motor, language, and visual ecologies of infancy, these findings reinforce an emerging priority to build theories of development that address the opportunities and challenges of real input encountered by real learners.

When novelty prevails on familiarity: Visual biases for child versus infant faces in 3.5- to 12-month-olds

The current study examined the influence of everyday perceptual experience with infant and child faces on the shaping of visual biases for faces in 3.5-, 6-, 9-, and 12-month-old infants. In Experiment 1, infants were presented with pairs of photographs of unfamiliar child and infant faces. Four groups with differential experience with infant and child faces were composed from parents' reports of daily exposure with infants and children (no experience, infant face experience, child face experience, and both infant and child face experience) to assess influence of experience on face preferences. Results showed that infants from all age groups displayed a bias for the novel category of faces in relation to their previous exposure to infant and child faces. In Experiment 2, this pattern of visual attention was reversed in infants presented with pictures of personally familiar child faces (i.e., older siblings) compared with unfamiliar infant faces, especially in older infants. These results suggest that allocation of attention for novelty can supersede familiarity biases for faces depending on experience and highlight that multiple factors drive infant visual behavior in responding to the social world.

Fast saccades towards faces are robust to orientation inversion and contrast negation

Eye movement studies show that humans can make very fast saccades towards faces in natural scenes, but the visual mechanisms behind this process remain unclear. Here we investigate whether fast saccades towards faces rely on mechanisms that are sensitive to the orientation or contrast of the face image. We present participants pairs of images each containing a face and a car in the left and right visual field or the reverse, and we ask them to saccade to faces or cars as targets in different blocks. We assign participants to one of three image conditions: normal images, orientation-inverted images, or contrast-negated images. We report three main results that hold regardless of image conditions. First, reliable saccades towards faces are fast - they can occur at 120-130 ms. Second, fast saccades towards faces are selective - they are more accurate and faster by about 60-70 ms than saccades towards cars. Third, saccades towards faces are reflexive - early saccades in the interval of 120-160 ms tend to go to faces, even when cars are the target. These findings suggest that the speed, selectivity, and reflexivity of saccades towards faces do not depend on the orientation or contrast of the face image. Our results accord with studies suggesting that fast saccades towards faces are mainly driven by low-level image properties, such as amplitude spectrum and spatial frequency.

Sensing everyday activity: Parent perceptions and feasibility

Mobile and wearable sensors provide a unique opportunity to capture the daily activities and interactions that shape developmental trajectories, with potential to revolutionize the study of development (de Barbaro, 2019). However, developmental research employing sensors is still in its infancy, and parents' comfort using these devices is uncertain. This exploratory report assesses parent willingness to participate in sensor studies via a nationally representative survey (N = 210) and live recruitment of a low-income, minority population for an ongoing study (N = 359). The survey allowed us to assess how protocol design influences acceptability, including various options for devices and datastream resolution, conditions of data sharing, and feedback. By contrast, our recruitment data provided insight into parents' true willingness to participate in a sensor study, with a protocol including 72 h of continuous audio, motion, and physiological data. Our results indicate that parents are relatively conservative when considering participation in sensing studies. However, nearly 41 % of surveyed parents reported that they would be at least somewhat willing to participate in studies with audio or video recordings, 26 % were willing or extremely willing, and 14 % reported being extremely willing. These results roughly paralleled our recruitment results, where 58 % of parents indicated interest, 29 % of parents scheduled to participate, and 10 % ultimately participated. Additionally, 70 % of caregivers stated their reason for not participating in the study was due to barriers unrelated to sensing while about 25 % noted barriers due to either privacy concerns or the physical sensors themselves. Parents' willingness to collect sensitive datastreams increased if data stayed within the household for individual use only, are shared anonymously with researchers, or if parents receive feedback from devices. Overall, our findings suggest that given the correct circumstances, mobile sensors are a feasible and promising tool for characterizing children's daily interactions and their role in development.

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

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

Mutual Gaze: An Active Ingredient for Social Development in Toddlers with ASD: A Randomized Control Trial

We examined the efficacy of an early autism intervention for use in early childhood intervention (ECI) and mutual gaze as a contributor to social development. Seventy-eight families were randomly assigned to one of three 12-week interventions: Pathways (with a mutual gaze component), communication, or services-as-usual (SAU). The Pathways/SAU comparison concerned the efficacy of Pathways for ECI, and the Pathways/communication comparison, mutual gaze. The Pathways group made significantly more change on social measures, communicative synchrony, and adaptive functioning compared with the SAU group and on social measures compared with the communication group. There were no group differences for communicative acts. The results support Pathways as a potential ECI program and mutual gaze as an active ingredient for social and communication development.

Deep Neural Network Reveals the World of Autism From a First-Person Perspective

People with autism spectrum disorder (ASD) show atypical attention to social stimuli and aberrant gaze when viewing images of the physical world. However, it is unknown how they perceive the world from a first-person perspective. In this study, we used machine learning to classify photos taken in three different categories (people, indoors, and outdoors) as either having been taken by individuals with ASD or by peers without ASD. Our classifier effectively discriminated photos from all three categories, but was particularly successful at classifying photos of people with >80% accuracy. Importantly, visualization of our model revealed critical features that led to successful discrimination and showed that our model adopted a strategy similar to that of ASD experts. Furthermore, for the first time we showed that photos taken by individuals with ASD contained less salient objects, especially in the central visual field. Notably, our model outperformed classification of these photos by ASD experts. Together, we demonstrate an effective and novel method that is capable of discerning photos taken by individuals with ASD and revealing aberrant visual attention in ASD from a unique first-person perspective. Our method may in turn provide an objective measure for evaluations of individuals with ASD. LAY SUMMARY: People with autism spectrum disorder (ASD) demonstrate atypical visual attention to social stimuli. However, it remains largely unclear how they perceive the world from a first-person perspective. In this study, we employed a deep learning approach to analyze a unique dataset of photos taken by people with and without ASD. Our computer modeling was not only able to discern which photos were taken by individuals with ASD, outperforming ASD experts, but importantly, it revealed critical features that led to successful discrimination, revealing aspects of atypical visual attention in ASD from their first-person perspective.

From concepts to percepts in human and machine face recognition: A reply to Blauch, Behrmann & Plaut

Intact recognition of familiar faces is critical for appropriate social interactions. Thus, the human face processing system should be optimized for familiar face recognition. Blauch et al. (2020) used face recognition deep convolutional neural networks (DCNNs) that are trained to maximize recognition of the trained (familiar) identities, to model human unfamiliar and familiar face recognition. In line with this model, we discuss behavioral, neuroimaging and computational findings that indicate that human face recognition develops from the generation of identity-specific concepts of familiar faces that are learned in a supervised manner, to the generation of view-invariant identity-general perceptual representations. Face-trained DCNNs seem to share some fundamental similarities with this framework.

Finding Structure in Time: Visualizing and Analyzing Behavioral Time Series

The temporal structure of behavior contains a rich source of information about its dynamic organization, origins, and development. Today, advances in sensing and data storage allow researchers to collect multiple dimensions of behavioral data at a fine temporal scale both in and out of the laboratory, leading to the curation of massive multimodal corpora of behavior. However, along with these new opportunities come new challenges. Theories are often underspecified as to the exact nature of these unfolding interactions, and psychologists have limited ready-to-use methods and training for quantifying structures and patterns in behavioral time series. In this paper, we will introduce four techniques to interpret and analyze high-density multi-modal behavior data, namely, to: (1) visualize the raw time series, (2) describe the overall distributional structure of temporal events (Burstiness calculation), (3) characterize the non-linear dynamics over multiple timescales with Chromatic and Anisotropic Cross-Recurrence Quantification Analysis (CRQA), (4) and quantify the directional relations among a set of interdependent multimodal behavioral variables with Granger Causality. Each technique is introduced in a module with conceptual background, sample data drawn from empirical studies and ready-to-use Matlab scripts. The code modules showcase each technique's application with detailed documentation to allow more advanced users to adapt them to their own datasets. Additionally, to make our modules more accessible to beginner programmers, we provide a "Programming Basics" module that introduces common functions for working with behavioral timeseries data in Matlab. Together, the materials provide a practical introduction to a range of analyses that psychologists can use to discover temporal structure in high-density behavioral data.

Social origins of self-regulated attention during infancy and their disruption in autism spectrum disorder: Implications for early intervention

To understand the complex relationships between autism spectrum disorder (ASD) and other frequently comorbid conditions, a growing number of studies have investigated the emergence of ASD during infancy. This research has suggested that symptoms of ASD and highly related comorbid conditions emerge from complex interactions between neurodevelopmental vulnerabilities and early environments, indicating that developing treatments to prevent ASD is highly challenging. However, it also suggests that attenuating the negative effects of ASD on future development once identified is possible. The present paper builds on this by conceptualizing developmental delays in nonsocial skills as the potential product of altered caregiver-infant interactions following the emergence of ASD during infancy. And, following emerging findings from caregiver-infant dyadic head-mounted eye-tracking (D-ET) research, it also suggests that a multiple pathway model of joint attention can provide mechanistic insights into how ASD alters the ability of caregiver and infant to create a context for infant learning. The potential for this view to inform early intervention is further discussed and illustrated through D-ET data collected prior to and following a brief, parent-mediated intervention for infant ASD. While promising, further research informing how a multiple pathway model of joint attention can inform ASD early intervention is needed.

Two kinds of theory: What psychology can learn from Einstein

A century ago, Einstein distinguished between two kinds of theory—theories of principle and constructive theories. These have separate but complementary roles to play in the advancement of knowledge, in the manner in which they relate to data and in how they are developed. The different kinds of theory carry implications for what kinds of data we produce and for how they are put to use. We outline Einstein’s distinction and the model of theory formation that it involves. We then use the distinction to look at some of the discussion of scientific practice in psychology, particularly recent work on the need for more theoretical, rather than purely methodological, sophistication. We argue in agreement with Einstein that the distinction is a useful one and that adopting it as a tenet of theoretical development requires a renewed commitment to a natural history of psychology.

Beyond perceptual development: Infant responding to social categories

A body of research is reviewed that has investigated how infants respond to social category information in faces based on differential experience. Whereas some aspects of behavioral performance (visual preference, discrimination, and scanning) are consistent with traditional models of perceptual development (induction, maintenance, and attunement), other aspects (category formation, association with valence, and selective learning) suggest the need for an account that links perceptual with social-emotional processing. We also consider how responding to social categories in infancy may anticipate subsequent responding to these categories in childhood and adulthood.

Connectivity at the origins of domain specificity in the cortical face and place networks

It is well established that the adult brain contains a mosaic of domain-specific networks. But how do these domain-specific networks develop? Here we tested the hypothesis that the brain comes prewired with connections that precede the development of domain-specific function. Using resting-state fMRI in the youngest sample of newborn humans tested to date, we indeed found that cortical networks that will later develop strong face selectivity (including the "proto" occipital face area and fusiform face area) and scene selectivity (including the "proto" parahippocampal place area and retrosplenial complex) by adulthood, already show domain-specific patterns of functional connectivity as early as 27 d of age (beginning as early as 6 d of age). Furthermore, we asked how these networks are functionally connected to early visual cortex and found that the proto face network shows biased functional connectivity with foveal V1, while the proto scene network shows biased functional connectivity with peripheral V1. Given that faces are almost always experienced at the fovea, while scenes always extend across the entire periphery, these differential inputs may serve to facilitate domain-specific processing in each network after that function develops, or even guide the development of domain-specific function in each network in the first place. Taken together, these findings reveal domain-specific and eccentricity-biased connectivity in the earliest days of life, placing new constraints on our understanding of the origins of domain-specific cortical networks.

Transition From Crawling to Walking Changes Gaze Communication Space in Everyday Infant-Parent Interaction

Acquisition of walking changes not only infants' locomotion itself but also infants' exploratory behavior and social interaction, such as gaze communication. To understand the ecological context in which gaze communication occurs and how it changes with walking development from the point of view of the spatial arrangement of infants, parents, and objects, we analyzed longitudinal data of daily eye contact scenes recorded from head-mounted eye trackers worn by parents as infants grew from 10 to 15.5 months, focusing on infant-parent distance and the number of objects between the dyad. A Bayesian state-space model revealed that the interpersonal distance at which infants initiated eye contact with their parents increased with the time ratio of walking to crawling. This result could not be explained by the developmental change in the amount of time that the infants were far from the parents, which is not limited to the gaze communication context. Moreover, the interpersonal distance at which the parents initiated eye contact with the infants did not increase with the time ratio of walking to crawling. The number of objects on the floor between infants and parents at the time of eye contact increased with interpersonal distance. Taken together, these results indicate that the transition from crawling to walking changes the ecological context in which infants initiate gaze communication to a visual environment characterized by a larger interpersonal distance and, therefore, more objects cluttered between the dyad. The present study has wider implications for the developmental change of shared attention in conjunction with walking development.

Universal Mechanisms and the Development of the Face Network: What You See Is What You Get

Our assignment was to review the development of the face-processing network, an assignment that carries the presupposition that a face-specific developmental program exists. We hope to cast some doubt on this assumption and instead argue that the development of face processing is guided by the same ubiquitous rules that guide the development of cortex in general.

Eye tracking in an everyday environment reveals the interpersonal distance that affords infant-parent gaze communication

The unique morphology of human eyes enables gaze communication at various ranges of interpersonal distance. Although gaze communication contributes to infants' social development, little is known about how infant-parent distance affects infants' visual experience in daily gaze communication. The present study conducted longitudinal observations of infant-parent face-to-face interactions in the home environment as 5 infants aged from 10 to 15.5 months. Using head-mounted eye trackers worn by parents, we evaluated infants' daily visual experience of 3138 eye contact scenes recorded from the infants' second-person perspective. The results of a hierarchical Bayesian statistical analysis suggest that certain levels of interpersonal distance afforded smooth interaction with eye contact. Eye contacts were not likely to be exchanged when the infant and parent were too close or too far apart. The number of continuing eye contacts showed an inverse U-shaped pattern with interpersonal distance, regardless of whether the eye contact was initiated by the infant or the parent. However, the interpersonal distance was larger when the infant initiated the eye contact than when the parent initiated it, suggesting that interpersonal distance affects the infant's and parent's social look differently. Overall, the present study indicates that interpersonal distance modulates infant-parent gaze communication.