Developmental Science最新文献

In many domains, learners extract recurring units from continuous sequences. For example, in unknown languages, fluent speech is perceived as a continuous signal. Learners need to extract the underlying words from this continuous signal and then memorize them. One prominent candidate mechanism is statistical learning, whereby learners track how predictive syllables (or other items) are of one another. Syllables within the same word predict each other better than syllables straddling word boundaries. But does statistical learning lead to memories of the underlying words—or just to pairwise associations among syllables? Electrophysiological results provide the strongest evidence for the memory view. Electrophysiological responses can be time-locked to statistical word boundaries (e.g., N400s) and show rhythmic activity with a periodicity of word durations. Here, I reproduce such results with a simple Hebbian network. When exposed to statistically structured syllable sequences (and when the underlying words are not excessively long), the network activation is rhythmic with the periodicity of a word duration and activation maxima on word-final syllables. This is because word-final syllables receive more excitation from earlier syllables with which they are associated than less predictable syllables that occur earlier in words. The network is also sensitive to information whose electrophysiological correlates were used to support the encoding of ordinal positions within words. Hebbian learning can thus explain rhythmic neural activity in statistical learning tasks without any memory representations of words. Learners might thus need to rely on cues beyond statistical associations to learn the words of their native language.

Research Highlights

Disparities in socioeconomic status (SES) may affect individuals’ risk preferences, which have important developmental consequences across the lifespan. Yet, previous research has shown inconsistent associations between SES and risky decision-making, and little is known about how this link develops from a young age. The current research is among the first to examine how SES influences preschoolers’ risky decisions in both gain and loss frames. Across two studies, children aged 5 to 6 years (total N = 309, 154 boys) were asked to choose between certain and risky options. The risky option was more advantageous, equal to, or less advantageous than the certain option. Study 1 revealed that in the loss frame, high-SES children (n = 84, 44 boys) chose more risky options and were more sensitive to the expected value compared to low-SES children (n = 78, 42 boys), especially when the risk was more advantageous. However, this SES difference was not significant in the gain frame. Supporting the potential causal link between SES and risky decision-making, Study 2 further found that experimentally increasing low-SES children's (n = 68, 30 boys) status by providing additional resources increased their risk-seeking behavior in the loss frame. Overall, our findings suggest an interaction between environmental cues (gain vs. loss) and early life circumstances (SES) in shaping children's risk preferences.

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In adults, spatial location plays a special role in visual object processing. People are more likely to judge two sequentially presented objects as being identical when they appear in the same location compared to in different locations (a phenomenon referred to as Spatial Congruency Bias [SCB]). However, no comparable Identity Congruency Bias (ICB) is found, suggesting an asymmetric location-identity relationship in object binding. What gives rise to this asymmetric congruency bias? This paper considered two possible hypotheses. Hypothesis 1 suggests that the asymmetric congruency bias results from an inherently special role of location in the visual system. In contrast, Hypothesis 2 suggests that the asymmetric congruency bias is a product of development, reflecting people's experience with the world. To distinguish the two hypotheses, we tested both adults’ and 5-year-old children's SCB and ICB by Identity Judgment Experiments and Spatial Judgment Experiments, respectively. The study found that adults only exhibited a SCB, but no ICB. However, young children exhibited both SCB and ICB, suggesting a symmetric congruency bias and reciprocal influences between location and identity in early development. The results indicate that the asymmetric location-identity relationship develops as object identity's influence on location gets pruned away, while location's influence on identity is preserved, possibly due to people's gained experiences with regularities of the world.

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Children actively and selectively transmit information to others based on the type of information and the context during learning. Four- to 7-year-old children preferentially transmit generalizable information in teaching-like contexts. Although 2-year-old children are able to distinguish between generalizable and non-generalizable information, it is not known whether they likewise transmit generalizable information selectively. We designed a behavioral study to address this question. Two-year-old children were presented with three novel boxes, identical except for their color. In each box, one of two equally salient actions led to a generalizable outcome (e.g., playing a [different] tune in each box), whereas the other led to a non-generalizable outcome (e.g., turning on a light, vibrating the box, or making a noise). In the discovery phase, children had a chance to discover the functions of each box presented one-by-one. Then, in the exploration phase, they were given the opportunity to independently explore all three boxes presented together. Finally, in the transmission phase, an ignorant recipient entered the room and asked the child to show them how these toys work. We measured whether children preferentially transmitted either generalizable or non-generalizable information when they were asked to demonstrate the function of the toys to a naïve adult. We found that children did not display any preference for transmitting generalizable information. These findings are discussed with respect to toddlers’ selectivity in transmitting information but also the development of sensitivity to information generalizability.

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Recent evidence suggests that deaf children with CIs exposed to nonnative sign language from hearing parents can attain age-appropriate vocabularies in both sign and spoken language. It remains to be explored whether deaf children with CIs who are exposed to early nonnative sign language, but only up to implantation, also benefit from this input and whether these benefits also extend to memory abilities, which are strongly linked to language development. The present study examined the impact of deaf children's early short-term exposure to nonnative sign input on their spoken language and their phonological memory abilities. Deaf children who had been exposed to nonnative sign input before and after cochlear implantation were compared to deaf children who never had any exposure to sign input as well as to children with typical hearing. The children were between 5;1 and 7;1 years of age at the time of testing and were matched on age, sex, and socioeconomic status. The results suggest that even short-term exposure to nonnative sign input has positive effects on general language and phonological memory abilities as well as on nonverbal working memory—with total length of exposure to sign input being the best predictor of deaf children's performance on these measures. The present data suggest that even access to early short-term nonnative visual language input is beneficial for the language and phonological memory abilities of deaf children with cochlear implants, suggesting also that parents should not be discouraged from learning and exposing their child to sign language.

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Individual differences in spatial thinking are predictive of children's math and science achievement and later entry into Science, Technology, Engineering, and Mathematics (STEM) disciplines. Little is known about whether parent characteristics predict individual differences in children's spatial thinking. This study aims to understand whether, and to what extent, mother's intrinsic (i.e., mental rotation) and extrinsic (i.e., spatial scaling) spatial ability directly and indirectly, via the variation in home spatial environment, predicts children's intrinsic and extrinsic spatial ability. A total of 165 mothers and their 4–6-year-old children were recruited to participate in a remote video session with an experimenter. Mothers were administered a forced-choice Intrinsic Spatial Toy Preference Task gauging their preference for highly spatial versus less spatial toys and asked questions with the Home Intrinsic Spatial Environmental Questionnaire about the frequency with which they engage their child in spatial activities at home. Mothers completed a Mental Rotations Test and a Spatial Scaling Task adapted for adults. Children were administered the Picture Rotation Task, the Spatial Scaling Task, and the Peabody Picture Vocabulary Test. Structural equation modeling was used to examine direct and indirect, via home spatial environment and toy choices, influences of mother spatial ability on child spatial ability. Contrary to our predictions, we did not find direct, nor indirect, relations between mother and child spatial ability. These findings suggest that researchers should consider alternative conceptualizations of the early home spatial environment beyond the frequency of spatial play in the home.

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Childhood adversity can lead to cognitive deficits or enhancements, depending on many factors. Though progress has been made, two challenges prevent us from integrating and better understanding these patterns. First, studies commonly use and interpret raw performance differences, such as response times, which conflate different stages of cognitive processing. Second, most studies either isolate or aggregate abilities, obscuring the degree to which individual differences reflect task-general (shared) or task-specific (unique) processes. We addressed these challenges using Drift Diffusion Modeling (DDM) and structural equation modeling (SEM). Leveraging a large, representative sample of 9–10 year-olds from the Adolescent Brain Cognitive Development (ABCD) study, we examined how two forms of adversity—material deprivation and household threat—were associated with performance on tasks measuring processing speed, inhibition, attention shifting, and mental rotation. Using DDM, we decomposed performance on each task into three distinct stages of processing: speed of information uptake, response caution, and stimulus encoding/response execution. Using SEM, we isolated task-general and task-specific variances in each processing stage and estimated their associations with the two forms of adversity. Youth with more exposure to household threat (but not material deprivation) showed slower task-general processing speed, but showed intact task-specific abilities. In addition, youth with more exposure to household threat tended to respond more cautiously in general. These findings suggest that traditional assessments might overestimate the extent to which childhood adversity reduces specific abilities. By combining DDM and SEM approaches, we can develop a more nuanced understanding of how adversity affects different aspects of youth's cognitive performance.

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