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.

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.

Correlates of infant pointing frequency in the first year.

This study examines the emergence of concurrent correlates of infant pointing frequency with the aim of contributing to its ontogenetic theories. We measured monthly from 8 to 12 months infants' (N = 56) index-finger pointing frequency along with several candidate correlates: (1) family socioeconomic status (SES), (2) mothers' pointing production, and (3) infants' point following to targets in front of and behind them. Results revealed that (1) infants increased their pointing frequency across age, but high-SES infants had a steeper increase, and a higher pointing frequency than low-SES infants from 10 months onward, (2) maternal pointing frequency was not associated with infant pointing frequency at any age, (3) infants' point following abilities to targets behind their visual fields was positively associated with their pointing frequency at 12 months, after pointing had already emerged around 10 months. Findings suggest that family SES impacts infants' pointing development more generally, not just through maternal pointing. The association between pointing and following points to targets behind, but not in front, suggests that a higher level of referential understanding emerges after, and perhaps through the production of pointing.

Relation of infants' and mothers' pointing to infants' vocabulary measured directly and with parental reports.

Infants' and parents' pointing gestures predict infants' concurrent and prospective language development. Most studies have measured vocabulary size using parental reports. However, parents tend to underestimate or overestimate infants' vocabulary necessitating the use of direct measures alongside parent reports. The present study examined whether mothers' index-finger pointing, and infants' whole-hand and index-finger pointing at 14 months associate with infants' receptive and expressive vocabulary based on parental reports and directly measured lexical processing efficiency (LPE) concurrently at 14 months and prospectively at 18 months. We used the decorated room paradigm to measure pointing frequency, the Turkish communicative development inventory I to measure infants' receptive vocabulary, Turkish communicative development inventory II to measure their expressive vocabulary, and the Looking-While-Listening (LWL) task to measure LPE. At 14 months, 34 mother-infant dyads, and at 18 months, 30 dyads were included in the analyses. We found that only infants' index-finger pointing frequency at 14 months predicted their LPE (both reaction time and accuracy) prospectively at 18 months but not concurrently at 14 months. Neither maternal pointing nor infants' pointing predicted their receptive and expressive vocabulary based on indirect measurement. The results extend the evidence on the relation between index-finger pointing and language development to a more direct measure of vocabulary.

The Relationship between Executive Functions, Working Memory, and Intelligence in Kindergarten Children.

Executive functions (EF), working memory (WM), and intelligence are closely associated, but distinct constructs. What underlies the associations between these constructs, especially in childhood, is not well understood. In this pre-registered study, along with the traditional aggregate accuracy and RT-based measures of EF, we investigated post-error slowing (PES) in EF as a manifestation of metacognitive processes (i.e., monitoring and cognitive control) in relation to WM and intelligence. Thereby, we aimed to elucidate whether these metacognitive processes may be one underlying component to explain the associations between these constructs. We tested kindergarten children (Mage = 6.4 years, SDage = 0.3) in an EF, WM (verbal and visuospatial), and fluid (non-verbal) intelligence task. We found significant associations of mainly the inhibition component of EF with fluid intelligence and verbal WM, and between verbal WM and intelligence. No significant associations emerged between the PES in EF and intelligence or WM. These results suggest that in the kindergarten age, inhibition rather than monitoring and cognitive control might be the underlying component that explains the associations between EF, WM, and intelligence.

Hearts, flowers, and fruits: All children need to reveal their post-error slowing.

Slowing down responses after errors (i.e., post-error slowing [PES]) is an established finding in adults. Yet PES in young children is still not well understood. In this study, we investigated (a) whether young children show PES in tasks with different types of cognitive conflict and differing demands on executive functions, (b) whether PES is adaptive and efficient in the sense that it is associated with better task performance, and (c) whether PES correlates between tasks. We tested 4- to 6-year-old children on the Funny Fruits task (FF; n = 143), a Stroop-like task that incorporates semantic conflict and taxes children's inhibition skills, and the Hearts and Flowers task (HF; n = 170), which incorporates spatial conflict and taxes children's inhibition skills in its incongruent block and taxes both inhibition and cognitive flexibility (rule-switching) skills in its mixed block. A subgroup of children were tested on both FF and HF (n = 74). Results revealed that, first, children showed PES in FF and both blocks of HF, indicating that PES occurs in both types of conflict and under varying executive demands. Second, PES was associated with task accuracy, but only for FF and the mixed HF. Third, a between-task association in PES emerged only between FF and the mixed HF. Together, these findings indicate that PES is still a developing strategy in young children; it is present but only adaptive for, and correlates between, semantic inhibition and spatial flexibility.

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.

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.