Developmental Science最新文献

Shyness is typically associated with avoidant social behavior and restricted affect in new social situations. However, we know considerably less about how one child's shyness influences another child's behavior and affect in new social situations. Children's shyness was parent-reported when children were age 3 (N = 105, 52 girls, M_age = 3.50 years), and children were tested approximately 1 year later (M_age = 4.76 years) in same-gender dyads where they were asked to give an impromptu speech about their most recent birthday in front of an experimenter and the other member of the dyad. We examined whether children's shyness and speech order influenced their own and their social partner's observed behavior and affect during the speech. Regardless of speech order, children's own shyness was positively associated with their own avoidant social behavior and gaze aversion. Regardless of shyness, children who gave their speech second averted their gaze more than children who gave their speech first. We also found that children who gave their speech second displayed less positive affect if their social partner who they watched give the speech first was shyer. We speculate that some 4-year-old children may be sensitive to the avoidant behaviors of their shy peers and, in turn, respond with less animation when it is their turn to participate in the same activity. RESEARCH HIGHLIGHTS: We examined whether preschool children's shyness and speech order influenced their own and their social partner's observed behavior and affect during a dyadic speech task Children's own shyness was positively associated with their own avoidant social behavior and gaze aversion Children who gave their speech second averted their gaze more than children who gave their speech first. Children who gave their speech second displayed less positive affect if their social partner who they watched give a speech first was shyer These findings suggest that preschool-aged children are sensitive to learning about their environment indirectly through social observation.

Children's white matter development is driven by experience, yet it remains poorly understood how it is shaped by attending formal education. A small number of studies compared children before and after the start of formal schooling to understand this, yet they do not allow to separate maturational effects from schooling-related effects. A clever way to (quasi-)experimentally address this issue is the longitudinal school cut-off design, which compares children who are similar in age but differ in schooling (because they are born right before or after the cut-off date for school entry). We used for the first time such a longitudinal school cut-off design to experimentally investigate the effect of schooling on children's white matter networks. We compared "young" first graders (schooling group, n = 34; M_age = 68 months; 20 girls) and "old" preschoolers (non-schooling group, n = 33; M_age = 66 months; 18 girls) that were similar in age but differed in the amount of formal instruction they received. Our study revealed that changes in fractional anisotropy and mean diffusivity in five a priori selected white matter tracts during the transition from preschool to primary school were predominantly driven by age-related maturation. We did not find specific schooling effects on white matter, despite their strong presence for early reading and early arithmetic skills. The present study is the first to disentangle the effects of age-related maturation and schooling on white matter within a longitudinal cohort of 5-year-old preschoolers. RESEARCH HIGHLIGHTS: White matter tracts that have been associated with reading and arithmetic may be susceptible to experience-dependent neuroplasticity when children learn to read and calculate. This longitudinal study used the school cut-off design to isolate schooling-induced from coinciding maturational influences on children's white matter development. White matter changes during the transition from preschool to primary school are predominantly driven by age-related maturation and not by schooling effects. Strong effects of schooling on behavior were shown for early reading and early arithmetic, but not for verbal ability and spatial ability.

This study examined how Mandarin-speaking preschoolers with and without a history of late talking (LT) process familiar monosyllabic words with unexpected lexical tones, focusing on both phonological and semantic violations. This study initially enrolled 64 Mandarin-speaking toddlers: 31 with a history of LT (mean age: 27.67 months) and 33 without a history of LT (non-LT) (mean age: 27.85 months). Event-related potentials were recorded at the age of 4 years during a picture-word mismatch task (LT mean age: 51.36 months; non-LT mean age: 51.20 months); in this task, the participants were presented with auditory words either matching (Tone 3) or mismatching with images in terms of their lexical tones; the mismatches encompassed acoustically dissimilar (Tone 1) and similar (Tone 2) mismatches. A significant difference in the phonological mapping negativity (PMN) responses to Tones 1 and 3 was observed only in the non-LT group. However, differences in the N400 responses to Tones 1 and 3 remained consistent across both groups. In addition, greater differences in the PMN responses between Tones 1 and 3 were associated with higher language proficiency during the preschool period. The PMN response serves as an indicator of neural correlates in lexical tone processing, reflecting challenges encountered by preschoolers with a history of LT when processing the lexical tones of familiar words. Furthermore, the PMN response was correlated with concurrent language abilities. These findings indicate the importance of early tonal perception development for Mandarin speakers with a history of LT. RESEARCH HIGHLIGHTS: Preschoolers with a history of late talking (LT), similar to preschoolers without such a history, can establish word expectations and detect the lexical tone violation in real time. However, those with a history of LT require additional time to process acoustic cues and differentiate between word semantics based on lexical tone information. The phonological mapping negativity response serves as an indicator of neural correlates in lexical tone processing, reflecting challenges encountered by preschoolers with a history of LT when processing the lexical tones of familiar words. The present findings indicate the importance of early intervention for Mandarin speakers with a history of LT, with an emphasis on lexical tone processing from toddlerhood.

Symbolic numeracy first emerges as children learn the meanings of number words and how to use them to precisely count sets of objects. This development starts before children enter school and forms a foundation for lifelong mathematics achievement. Despite its importance, exactly how children acquire this basic knowledge is unclear. Here we test competing theories of early number learning by measuring event-related brain potentials during a novel number word-quantity comparison task in 3-4-year-old preschool children (N = 128). We find several qualitative differences in neural processing of number by conceptual stage of development. Specifically, we find differences in early attention-related parietal electrophysiology (N1), suggesting that less conceptually advanced children process arrays as individual objects and more advanced children distribute attention over the entire set. Subsequently, we find that only more conceptually advanced children show later-going frontal (N2) sensitivity to the numerical-distance relationship between the number word and visual quantity. The nature of this response suggested that exact rather than approximate numerical meanings were being associated with number words over frontal sites. No evidence of numerical distance effects was observed over posterior scalp sites. Together these results suggest that children may engage parallel individuation of objects to learn the meanings of the first few number words, but, ultimately, create new exact cardinal value representations for number words that cannot be defined in terms of core, nonverbal number systems. More broadly, these results document an interaction between attentional and general cognitive mechanisms in cognitive development. RESEARCH HIGHLIGHTS: Conceptual development in numeracy is associated with a shift in attention from objects to sets. Children acquire meanings of the first few number words through associations with parallel attentional individuation of objects. Understanding of cardinality is associated with attentional processing of sets rather than individuals. Brain signatures suggest children attribute exact rather than approximate numerical meanings to the first few number words. Number-quantity relationship processing for the first few number words is evident in frontal but not parietal scalp electrophysiology of young children.

Adolescent food insecurity is a salient adversity hypothesized to affect neural systems associated with increased impulsive behavior. Family environments shape how adverse experiences influence development. In this study, hypotheses were tested regarding the conjoint effects of food insecurity and family flexibility on impulsivity via alterations in connectivity between regions within the salience and central executive networks. Such alterations are reflected in resting-state functional connectivity (rsFC) metrics between the anterior insula (AI) and the middle frontal gyrus (MFG). Hypotheses were tested in a longitudinal moderated mediation model with two waves of data from 142 adolescents (Time 1 [T1] M_age = 12.89, SD = 0.85; Time 2 [T2] M_age = 15.01, SD = 1.07). Data on past-year household food insecurity, family flexibility, and rsFC were obtained at T1. Impulsivity was self-reported by the adolescent at T1 and T2. Findings revealed that high T1 left-to-left rsFC between the AI and MFG was associated with increased impulsivity at T2. The interaction of family flexibility and food insecurity was associated with AI and MFG rsFC. In the context of low family flexibility, food insecurity was linked to high levels of AI and MFG rsFC. Conversely, in the context of optimal family flexibility, food insecurity was associated with low levels of AI and MFG rsFC. Conditional indirect analysis suggests that the links among food insecurity, rsFC, and impulsive behavior depend on family flexibility. RESEARCH HIGHLIGHTS: Adolescent food insecurity was associated with anterior insula and middle frontal gyrus connectivity only at certain levels of family flexibility. High family flexibility attenuated the link between food insecurity and neural connectivity, while low levels of family flexibility increased this risk. High left anterior insula and left middle frontal gyrus connectivity was associated with increased impulsivity 1 year later.

Test-retest reliability-establishing that measurements remain consistent across multiple testing sessions-is critical to measuring, understanding, and predicting individual differences in infant language development. However, previous attempts to establish measurement reliability in infant speech perception tasks are limited, and reliability of frequently used infant measures is largely unknown. The current study investigated the test-retest reliability of infants' preference for infant-directed speech over adult-directed speech in a large sample (N = 158) in the context of the ManyBabies1 collaborative research project. Labs were asked to bring in participating infants for a second appointment retesting infants on their preference for infant-directed speech. This approach allowed us to estimate test-retest reliability across three different methods used to investigate preferential listening in infancy: the head-turn preference procedure, central fixation, and eye-tracking. Overall, we found no consistent evidence of test-retest reliability in measures of infants' speech preference (overall r = 0.09, 95% CI [-0.06,0.25]). While increasing the number of trials that infants needed to contribute for inclusion in the analysis revealed a numeric growth in test-retest reliability, it also considerably reduced the study's effective sample size. Therefore, future research on infant development should take into account that not all experimental measures may be appropriate for assessing individual differences between infants. RESEARCH HIGHLIGHTS: We assessed test-retest reliability of infants' preference for infant-directed over adult-directed speech in a large pre-registered sample (N = 158). There was no consistent evidence of test-retest reliability in measures of infants' speech preference. Applying stricter criteria for the inclusion of participants may lead to higher test-retest reliability, but at the cost of substantial decreases in sample size. Developmental research relying on stable individual differences should consider the underlying reliability of its measures.

Harlow's seminal work on the nature of attachment focused on the importance of warm, responsive, and loving relationships in children's healthy development. While the need for love and care is arguably universal, the ways in which these emotions are expressed can vary across cultural contexts. We examined how Chinese American parents' expressions of love were associated with children's attachment security. A total of 110 Chinese American immigrant parent-child dyads (children 7-11 years old, 49% girls) participated in 3-min conversations in which parents were instructed to communicate love and care. Proposition-level analyses in speech (total 8825 propositions) identified three types of affection: training (guan and chiao shun); relational affection (qin); and validation (acceptance and encouragement of child's own expression of emotion, thoughts, and behaviors). Higher training was observed in parents with lower American orientation and lower income. Higher relational affection was observed in parents with lower income. Higher validation was observed in parents with higher income. Using path analyses, training and validation were found to be positively associated with children's attachment security beyond parenting styles. Effects of parents' relational affection were moderated by children's American orientation. Results demonstrate how immigrant parents draw on multiple cultural scripts to express love and care. These findings expand traditional concepts of parental love in immigrant families and illustrate how bicultural expressions of love can shape attachment security in middle childhood. A video abstract of this article can be viewed at https://youtu.be/HqUfIDxkFsE RESEARCH HIGHLIGHTS: Analyses of parent-child discussions identified three parental affection styles (i.e., training, relational affection, and validation) as expressions of love and care in Chinese American immigrant families. Training and validation were positively associated with children's attachment security. Relational affection was associated with lower attachment security for children with higher American cultural orientation, suggesting the effects of parent-child expressions of love are shaped by acculturation.

Working memory serves as a means to accumulate information and reorganize it. Researchers have long assumed that the natural organization of information is one stream at a time. This logic leads to the expectation that, when two different series of stimuli are to be remembered, performance should be superior if the series are presented one before the other in succession, rather than concurrently. Moreover, different accounts of attentional limits lead to different expectations for the change in the ability to encode two sets across age groups in childhood. Testing children from first grade (6-7 years) to adulthood, we presented sequences of colored objects and tones in succession or concurrently (with one color accompanying an unrelated tone) and found that performance was equally good no matter which presentation method was used. The results for both presentation methods closely matched the intricate pattern of development observed by Cowan et al. (2018), who used successive presentation only. We found marked developmental improvement in the ability to retain materials in each modality without an increasing cost of attention-sharing between modalities. Humans at least from the elementary school years through young adulthood thus display an ability to accommodate and organize two concurrent streams of information. RESEARCH HIGHLIGHTS: Memory for stimuli from multiple modalities is relevant to school performance and learning; here we investigate how attention is shared between remembering colors and tones. Participants received four colors and/or four tones for subsequent recognition on a trial, with dual modalities presented successively (0.5 s per stimulus) or concurrently (0.5 s per pair). Successive versus concurrent presentation had little effect on recognition, and the marked increase in memory performance with age did not come from dividing attention during encoding or maintenance. Children as young as first grade thus can encode and organize for later recognition colors and concurrently-presented, but unrelated, tones.