Duration of face mask exposure matters: evidence from Swiss and Brazilian kindergartners' ability to recognise emotions.

Wearing facial masks became a common practice worldwide during the COVID-19 pandemic. This study investigated (1) whether facial masks that cover adult faces affect 4- to 6-year-old children's recognition of emotions in those faces and (2) whether the duration of children's exposure to masks is associated with emotion recognition. We tested children from Switzerland (N = 38) and Brazil (N = 41). Brazil represented longer mask exposure due to a stricter mandate during COVID-19. Children had to choose a face displaying a specific emotion (happy, angry, or sad) when the face wore either no cover, a facial mask, or sunglasses. The longer hours of mask exposure were associated with better emotion recognition. Controlling for the hours of exposure, children were less likely to recognise emotions in partially hideen faces. Moreover, Brazilian children were more accurate in recognising happy faces than Swiss children. Overall, facial masks may negatively impact children's emotion recognition. However, prolonged exposure appears to buffer the lack of facial cues from the nose and mouth. In conclusion, restricting facial cues due to masks may impair kindergarten children's emotion recognition in the short run. However, it may facilitate their broader reading of facial emotional cues in the long run.

Speaker Competence Affects Prefrontal Theta and Occipital Alpha Power during Selective Word Learning in Preschoolers.

In the present study, we investigated the cognitive processes underlying selective word learning in preschoolers. We measured rhythmic neural activity in the theta (4-8 Hz) and alpha frequency range (7-12 Hz) in 67 four-year-olds. EEG was recorded during anticipation and encoding of novel labeling events performed by a speaker who had previously shown either competence (correct) or incompetence (incorrect) in labeling familiar objects. In both groups, children selected the target object equally often upon recall. However, children observing the incompetent speaker revealed weaker representations of novel words indicated by an increased likelihood for selecting familiar but incorrect items upon recall. Modulations in theta and alpha power suggest differential processing of novel label-object pairs depending on the speakers' competence. In the incompetent, but not the competent, speaker condition, increases in prefrontal theta power during anticipation and encoding were related to increased recall success. Findings suggest that theta power in the present study reflects cognitive control. In both conditions, occipital alpha power-indicating attentional processes-reflected familiarity with novel items, but in opposite directions. In familiar item trials, alpha power was increased observing the incompetent and decreased observing the competent speaker. Thus, both cognitive control and attention processes during word learning are differentially affected by speaker characteristics.

The proximate regulation of prosocial behaviour: towards a conceptual framework for comparative research.

Humans and many other animal species act in ways that benefit others. Such prosocial behaviour has been studied extensively across a range of disciplines over the last decades, but findings to date have led to conflicting conclusions about prosociality across and even within species. Here, we present a conceptual framework to study the proximate regulation of prosocial behaviour in humans, non-human primates and potentially other animals. We build on psychological definitions of prosociality and spell out three key features that need to be in place for behaviour to count as prosocial: benefitting others, intentionality, and voluntariness. We then apply this framework to review observational and experimental studies on sharing behaviour and targeted helping in human children and non-human primates. We show that behaviours that are usually subsumed under the same terminology (e.g. helping) can differ substantially across and within species and that some of them do not fulfil our criteria for prosociality. Our framework allows for precise mapping of prosocial behaviours when retrospectively evaluating studies and offers guidelines for future comparative work.

What's the point? Infants' and adults' perception of different pointing gestures.

Adults and infants as young as 4 months old orient to pointing gestures. Although adults are shown to orient faster to index-finger pointing than other hand shapes, it is unknown whether hand shapes influence infants' perception of pointing. In this study, we used a spatial cueing paradigm on an eye tracker to investigate whether and to what extent adults and 12-month-old infants orient their attention in the direction of pointing gestures with different hand shapes: index finger, whole hand, and pinky finger. Furthermore, we assessed infants' and their parents' pointing production. Results revealed that adults showed a reliable cueing effect: shorter saccadic reaction times (SRTs) to congruent than incongruent targets, for all hand shapes. However, they did not show a larger cueing effect triggered by the index or any other finger. This contradicts previous findings and is discussed with respect to the differences in methodology. Infants showed a cueing effect only for the whole hand but not for the index or pinky fingers. The current results suggest that infants' orienting to pointing may be more robust for the whole hand shape in the first year, and tuning in to the social-communicative relevance of the canonical index finger shape may develop later or require additional social-communicative cues.

Mini-review: Wild laughs: Ontogenesis and phylogenesis of humour.

This mini-review discusses the existing evidence on various forms of humour and humour-like behaviour in non-human animals, combining ontogenetic and phylogenetic perspectives. The first section describes humour-like behaviours, from the simplest to the most complex form (from laughing, tickling, joking, and chasing to ToM humour). In the second section, we propose the SPeCies (Social, Physiological, and Cognitive) Perspective, which frames the various types of humour based on Social motivation, Physiological state, and Cognitive skills. Finally, in the third section, we discuss future directions for further development.

Automatic imitation in school-aged children.

Children imitate others for different reasons: To learn from others and to reach social goals such as affiliation or prosociality. So far, imitative acts have been measured using diverging methods in children and adults. Here, we investigated whether school-aged children's imitation can be measured via their automatic imitation with a classical imitation-inhibition task (Brass et al., 2000) as has been used in adults. To this end, we measured automatic imitation in N=94 7-8-year-olds and N=10 adults. The results were similar in children and adults: Observing actions that are incongruent with participants' actions interferes with their responses resulting in increased reaction times and error rates. This shows that assessing automatic imitation via the imitation-inhibition task is feasible in children, and creates the basis for future studies to compare the behaviour of different age groups with the same imitation task.

Childhood poisonings: Effects of ambiguous product characteristics on preschool children's categorization of household chemicals.

This study investigated preschool children's categorization and risk perception of products with ambiguous product characteristics (e.g., food-like packaging). These characteristics make it difficult for preschool children to categorize household chemicals correctly. This, therefore, increases the risk of unintentional poisoning. We hypothesized that ambiguity arises from different product characteristics, such as the type of packaging, the products' scent, or the packaging's color and transparency. In four behavioral tasks, N = 108 preschool children (M = 43 months, SD = 3) categorized different products and household chemicals with various types of packaging, colors, and scents. Individually wrapped dishwasher tablets were more likely to be categorized as edible than unwrapped ones. Furthermore, children who had interacted with any type of dishwasher tablet in the last 6 months performed better in identifying dishwasher tablets, regardless of packaging type. Household chemicals with a fruity scent were more likely to be categorized as drinkable than those with a chlorine scent. Finally, the children considered black bottles more dangerous and preferred them less than bottles of a different color. In contrast, bottle transparency generally did not seem to affect risk perception and preference. These findings confirm that ambiguous product characteristics influence children's categorization of unknown products and, thus, their risk perception and decision-making. Manufacturers and caregivers are advised to reduce the ambiguity of household chemicals by designing more neutral product packaging and choosing products with more neutral elements, respectively.

The Agent Preference in Visual Event Apprehension.

A central aspect of human experience and communication is understanding events in terms of agent ("doer") and patient ("undergoer" of action) roles. These event roles are rooted in general cognition and prominently encoded in language, with agents appearing as more salient and preferred over patients. An unresolved question is whether this preference for agents already operates during apprehension, that is, the earliest stage of event processing, and if so, whether the effect persists across different animacy configurations and task demands. Here we contrast event apprehension in two tasks and two languages that encode agents differently; Basque, a language that explicitly case-marks agents ('ergative'), and Spanish, which does not mark agents. In two brief exposure experiments, native Basque and Spanish speakers saw pictures for only 300 ms, and subsequently described them or answered probe questions about them. We compared eye fixations and behavioral correlates of event role extraction with Bayesian regression. Agents received more attention and were recognized better across languages and tasks. At the same time, language and task demands affected the attention to agents. Our findings show that a general preference for agents exists in event apprehension, but it can be modulated by task and language demands.

Cardiac interoception in infants: Behavioral and neurophysiological measures in various emotional and self-related contexts.

Interoception, the perception of internal bodily signals, is fundamental to our sense of self. Even though theoretical accounts suggest an important role for interoception in the development of the self, empirical investigations are limited, particularly in infancy. Previous studies used preferential-looking paradigms to assess the detection of sensorimotor and multisensory contingencies in infancy, usually related to proprioception and touch. So far, only one recent study reported that infants discriminated between audiovisual stimuli presented synchronously or asynchronously with their heartbeat. This discrimination was related to the amplitude of the infant's heartbeat evoked potentials (HEP), a neural correlate of interoception. In the current study, we measured looking preferences between synchronous and asynchronous visuocardiac (bimodal), and audiovisuocardiac (trimodal) stimuli as well as the HEP in conditions of different emotional contexts and with different degrees of self-relatedness in a mirror-like setup. While the infants preferred trimodal to bimodal stimuli, we did not observe the predicted differences between synchronous and asynchronous stimulation. Furthermore, the HEP was not modulated by emotional context or self-relatedness. These findings do not support previously published results and highlight the need for further studies on the early development of interoception in relation to the development of the self.

Atypical gaze-following behaviour in infants with congenital heart disease.

BACKGROUND: Neurodevelopmental impairments are the most prevalent non-cardiac long-term sequelae in children with complex congenital heart disease (CHD). Deficits include the social-emotional and social-cognitive domains. Little is known about the predecessors of social-cognitive development in infants with CHD during the first year of life. Gaze-following behaviour can be used to measure early social-cognitive abilities. AIMS: To assess gaze-following development in infants with CHD compared to healthy controls. STUDY DESIGN: Prospective cohort study. PARTICIPANTS: Twenty-three infants who underwent neonatal correction for CHD and 84 healthy controls. OUTCOME MEASURES: Gaze-following behaviour was assessed by eye tracking at 6 and 12 months. Difference scores for first fixation, fixation frequency and fixation duration towards the gaze-cued object were calculated across 6 trials and compared between groups at both testing time points while adjusting for known confounders. Linear mixed models were calculated to assess the longitudinal trajectory of gaze-following development while accounting for the nested and dependent data structure. RESULTS: At 6 months, no difference in gaze-following behaviour between CHD and healthy controls was found. At 12 months, fixation frequency towards the gaze-cued was lower and looking duration was shorter in CHD compared to controls (p = 0.0077; p = 0.0068). Infants with CHD showed less increase with age in the fixation frequency towards the congruent object (p = 0.041) compared to controls. CONCLUSION: During the first year of life, gaze-following development diverges in infants with CHD compared to healthy controls. Further research is needed to investigate the clinical relevance of these findings and the association with later social-cognitive development.

What do you focus on? An investigation of goal focus from childhood to old age.

Goals constitute an important construct in developmental psychology. They represent a central way in which individuals shape their development. Here, we present two studies on age-related differences in one important goal dimension, goal focus, that is, the relative salience of the means and ends of goal pursuit. Extant studies on age-related differences in adults suggest a shift from focusing on the ends to focusing on the means across adulthood. The current studies aimed to expand this research to encompass the entire lifespan including childhood. The first cross-sectional study included participants spanning from early childhood into old age (N = 312, age range: 3-83 years) and used a multimethodological approach comprising eye tracking, behavioral, and verbal measures of goal focus. The second study investigated the verbal measures of the first study in more detail in an adult sample (N = 1550, age range: 17-88 years). Overall, the results do not show a clear pattern, making them difficult to interpret. There was little convergence of the measures, pointing to the difficulties in assessing a construct such as goal focus across a large range of age groups differing in social-cognitive and verbal skills.

Gradual Route to Productivity: Evidence from Turkish Morphological Causatives.

Becoming productive with grammatical categories is a gradual process in children's language development. Here, we investigated this transition process by focusing on Turkish causatives. Previous research examining spontaneous and elicited production of Turkish causatives with familiar verbs attested the onset and early stages of productivity at ages 2 to 3 (Aksu-Koç & Slobin, 1985; Nakipoglu, Uzundag, & Sarigül, 2021). So far, however, we know very little about children's understanding of causatives with novel verbs. In the present study, we asked: (a) When does the generalization of causative morphology in a novel context emerge? and (b) What role does child-directed input play in this development? To answer the first question, we conducted comprehension-judgment experiments with children aged 2;6-6;11 using pseudo-verbs (Study 1 & 2). Results showed that children preferred the Turkish causative suffix -DIr over an unrelated or no suffix to denote caused events earliest at age 4;10. To answer the second question, we analyzed child-directed speech from a longitudinal corpus of Turkish language acquisition (Study 3). Results showed that when addressing children younger than age 3, caregivers used the -DIr suffix with little variation considering the overall variability of verbs they could utter. Overall, these findings suggest that productivity with morphological causatives in a novel context emerges in a later stage of acquisition. This later development might partly be accounted for by the insufficient variation of morphological causatives in the early input.

Exploring the role of COVID-19 pandemic-related changes in social interactions on preschoolers' emotion labeling.

During the COVID-19 pandemic people were increasingly obliged to wear facial masks and to reduce the number of people they met in person. In this study, we asked how these changes in social interactions are associated with young children's emotional development, specifically their emotion recognition via the labeling of emotions. Preschoolers labeled emotional facial expressions of adults (Adult Faces Task) and children (Child Faces Task) in fully visible faces. In addition, we assessed children's COVID-19-related experiences (i.e., time spent with people wearing masks, number of contacts without masks) and recorded children's gaze behavior during emotion labeling. We compared different samples of preschoolers (4.00-5.75 years): The data for the no-COVID-19-experience sample were taken from studies conducted before the pandemic (Adult Faces Task: N = 40; Child Faces Task: N = 30). The data for the with-COVID-19-experience sample (N = 99) were collected during the COVID-19 pandemic in Switzerland between June and November 2021. The results did not indicate differences in children's labeling behavior between the two samples except for fearful adult faces. Children with COVID-19-experience more often labeled fearful faces correctly compared to children with no COVID-19 experience. Furthermore, we found no relations between children's labeling behavior, their individual COVID-19-related experiences, and their gaze behavior. These results suggest that, even though the children had experienced differences in the amount and variability of facial input due to the pandemic, they still received enough input from visible faces to be able to recognize and label different emotions.

How experience shapes infants' communicative behaviour: Comparing gaze following in infants with and without pandemic experience.

The COVID-19 pandemic has been influencing people's social life substantially. Everybody, including infants and children needed to adapt to changes in social interactions (e.g., social distancing) and to seeing other people wearing facial masks. In this study, we investigated whether these pandemic-related changes influenced 12- to 15-months-old infants' reactions to observed gaze shifts (i.e., their gaze following). In two eye-tracking tasks, we measured infants' gaze-following behavior during the pandemic (with-COVID-19-experience sample) and compared it to data of infants tested before the pandemic (no-COVID-19-experience sample). Overall, the results indicated no significant differences between the two samples. However, in one sub-task infants in the with-COVID-19-experience sample looked longer at the eyes of a model compared to the no-COVID-19-experience sample. Within the with-COVID-19-experience sample, the amount of mask exposure and the number of contacts without mask were not related to infants' gaze-following behavior. We speculate that even though infants encounter fewer different people during the pandemic and are increasingly exposed to people wearing facial masks, they still also see non-covered faces. These contacts might be sufficient to provide infants with the social input they need to develop social and emotional competencies such as gaze following.

Spelling out some unaddressed conceptual and methodological challenges in empirical lifespan research.

The importance of taking a lifespan approach to describe and understand human development has long been acknowledged (e.g., Baltes, 1987). Nevertheless, theoretical or empirical research that actually encompasses the entire lifespan, that is, from early childhood to old age, is rare. This is not surprising given the challenges such an approach entails. Many of these challenges (e.g., establishing measurement invariance between age groups) have been addressed in the previous literature, but others have not yet been sufficiently considered. The main purpose of this article is to present several examples of such largely unaddressed conceptual and methodological challenges and reflect upon possible ways to address them. We discuss the usefulness of a lifespan approach and the generalization of the challenges to other research comparing different groups, such as gender, culture, or species.

The kleineWeltentdecker App - A smartphone-based developmental diary.

Today, a vast number of tools exist to measure development in early childhood in a variety of domains such as cognition, language, or motor, cognition. These tools vary in different aspects. Either children are examined by a trained experimenter, or caregivers fill out questionnaires. The tools are applied in the controlled setting of a laboratory or in the children's natural environment. While these tools provide a detailed picture of the current state of children's development, they are at the same time subject to several constraints. Furthermore, the measurement of an individual child's change of different skills over time requires not only one measurement but high-density longitudinal assessments. These assessments are time-consuming, and the breadth of developmental domains assessed remains limited. In this paper, we present a novel tool to assess the development of skills in different domains, a smartphone-based developmental diary app (the kleineWeltentdecker App, henceforth referred to as the APP (The German expression "kleine Weltentdecker" can be translated as "young world explorers".)). By using the APP, caregivers can track changes in their children's skills during development. Here, we report the construction and validation of the questionnaires embedded in the APP as well as the technical details. Empirical validations with children of different age groups confirmed the robustness of the different measures implemented in the APP. In addition, we report preliminary findings, for example, on children's communicative development by using existing APP data. This substantiates the validity of the assessment. With the APP, we put a portable tool for the longitudinal documentation of individual children's development in every caregiver's pocket, worldwide.

Predicting Reading From Behavioral and Neural Measures - A Longitudinal Event-Related Potential Study.

Fluent reading is characterized by fast and effortless decoding of visual and phonological information. Here we used event-related potentials (ERPs) and neuropsychological testing to probe the neurocognitive basis of reading in a sample of children with a wide range of reading skills. We report data of 51 children who were measured at two time points, i.e., at the end of first grade (mean age 7.6 years) and at the end of fourth grade (mean age 10.5 years). The aim of this study was to clarify whether next to behavioral measures also basic unimodal and bimodal neural measures help explaining the variance in the later reading outcome. Specifically, we addressed the question of whether next to the so far investigated unimodal measures of N1 print tuning and mismatch negativity (MMN), a bimodal measure of audiovisual integration (AV) contributes and possibly enhances prediction of the later reading outcome. We found that the largest variance in reading was explained by the behavioral measures of rapid automatized naming (RAN), block design and vocabulary (46%). Furthermore, we demonstrated that both unimodal measures of N1 print tuning (16%) and filtered MMN (7%) predicted reading, suggesting that N1 print tuning at the early stage of reading acquisition is a particularly good predictor of the later reading outcome. Beyond the behavioral measures, the two unimodal neural measures explained 7.2% additional variance in reading, indicating that basic neural measures can improve prediction of the later reading outcome over behavioral measures alone. In this study, the AV congruency effect did not significantly predict reading. It is therefore possible that audiovisual congruency effects reflect higher levels of multisensory integration that may be less important for reading acquisition in the first year of learning to read, and that they may potentially gain on relevance later on.

When dogs meow: An electrophysiological study of lexical-semantic processing in toddlers.

The goal of this study was to investigate lexical-semantic processing at an early phase of language development. Adults often communicate with children using infant-directed speech that typically involves lexical and syntactic modifications such as onomatopoeias (Soderstrom, 2007). Here, we asked how and when children start to show an advantage for processing conventional linguistic forms, such as common nouns, and consequently decreasing sensitivity to onomatopoeias. We recorded event-related brain potentials in children of two age groups (16-21 months and 24-31 months) and in an adult control group during the presentation of four conditions in which either common nouns or onomatopoeias were presented auditorily followed by a picture of an either congruent or incongruent object. We focused on the N400 effect, a more negative ERP response to incongruent compared with congruent semantic relations. The younger children showed an N400 effect only for onomatopoeic words, while the older children showed an N400 effect only for common nouns. The adults showed N400 effects for onomatopoeia and nouns. These different N400 effects suggest that onomatopoeia and common nouns are differently organized in children's semantic memory and that the acquisition of linguistic abilities affects and modifies semantic processing of different lexical information.

Child-directed speech is optimized for syntax-free semantic inference.

The way infants learn language is a highly complex adaptive behavior. This behavior chiefly relies on the ability to extract information from the speech they hear and combine it with information from the external environment. Most theories assume that this ability critically hinges on the recognition of at least some syntactic structure. Here, we show that child-directed speech allows for semantic inference without relying on explicit structural information. We simulate the process of semantic inference with machine learning applied to large text collections of two different types of speech, child-directed speech versus adult-directed speech. Taking the core meaning of causality as a test case, we find that in child-directed speech causal meaning can be successfully inferred from simple co-occurrences of neighboring words. By contrast, semantic inference in adult-directed speech fundamentally requires additional access to syntactic structure. These results suggest that child-directed speech is ideally shaped for a learner who has not yet mastered syntactic structure.

Influence of causal language on causal understanding: A comparison between Swiss German and Turkish.

Young children have difficulties in understanding untypical causal relations. Although we know that hearing a causal description facilitates this understanding, less is known about what particular features of causal language are responsible for this facilitation. Here, we asked two questions. First, do syntactic and morphological cues in the grammatical structure of sentences facilitate the extraction of causal meaning? Second, do these different cues influence this facilitation to different degrees? We studied children learning either Swiss German or Turkish, two languages that differ in their expression of causality. Swiss German predominantly uses lexical causatives (e.g., schniidä [cut]), which lack a formal marker to denote causality. Turkish, alongside lexical causatives, uses morphological causatives, which formally mark causation (e.g., ye [eat] vs. yeDIr [feed]). We tested 2.5- to 3.5-year-old children's understanding of untypical cause-effect relations described with either noncausal language (e.g., Here is a cube and a car) or causal language using a pseudo-verb (e.g., lexical: The cube gorps the car). We tested 135 Turkish-learning children (noncausal, lexical, and morphological conditions) and 90 Swiss-German-learning children (noncausal and lexical conditions). Children in both language groups performed better in the causal language condition(s) than in the noncausal language condition. Furthermore, Turkish-learning children's performance in both the lexical and morphological conditions was similar to that of Swiss-German-learning children in the lexical condition and did not differ from each other. These findings suggest that the structural cues of causal language support children's understanding of untypical causal relations regardless of the type of construction.