Rapid, experience-related changes in the organization of children's semantic knowledge

Developmental refinements to neural attentional state during semantic memory retrieval through adolescence

Despite the fact that attention undergoes protracted development, little is known about how it may support memory refinements in childhood and adolescence. Here, we asked whether people differentially focus their attention on semantic or perceptual information over development during memory retrieval. First, we trained a multivoxel classifier to characterize whole-brain neural patterns reflecting semantic versus perceptual attention in a cued attention task. We then used this classifier to quantify how attention varied in a separate dataset in which children, adolescents, and adults retrieved autobiographical, semantic, and episodic memories. All age groups demonstrated a semantic attentional bias during memory retrieval, with significant age differences in this bias during the semantic task. Trials began with a preparatory picture cue followed by a retrieval question, which allowed us to ask whether attentional biases varied by trial period. Adults showed a semantic bias earlier during the picture cues, whereas adolescents showed this bias during the question. Adults and adolescents also engaged different brain regions-superior parietal cortex and ventral visual regions, respectively-during preparatory picture cues. Our results demonstrate that retrieval-related attention undergoes refinement beyond childhood. These findings suggest that alongside expanding semantic knowledge, attention-related changes may support the maturation of factual knowledge retrieval.

When Time Shifts the Boundaries: Isolating the Role of Forgetting in Children's Changing Category Representations

In studies of children's categorization, researchers have typically studied how encoding characteristics of exemplars contribute to children's generalization. However, it is unclear whether children's internal cognitive processes alone, independent of new information, may also influence their generalization. Thus, we examined the role that one cognitive process, forgetting, plays in shaping children's category representations by conducting three experiments. In the first two experiments, participants (NExp1=37, Mage=4.02 years; NExp2=32, Mage=4.48 years) saw a novel object labeled by the experimenter and then saw five new objects with between one and five features changed from the learned exemplar. The experimenter asked whether each object was a member of the same category as the exemplar; children saw the five new objects either immediately or after a five-minute delay. Children endorsed category membership at higher rates at immediate test than at delayed test, suggesting that children's category representations became narrower over time. In Experiment 3, we investigated forgetting as a key mechanism underlying the narrowing found in Experiments 1 and 2. We showed participants (NExp3=34, Mage=4.20 years) the same exemplars used in Experiments 1 and 2; then, either immediately or after a five-minute delay, we showed children seven individual object features and asked if each one had been part of the exemplar. Children's accuracy was lower after the delay, showing that they did indeed forget individual features. Taken together, these results show that forgetting plays an important role in changing children's newly-learned categories over time.

Experience and maturation: The contribution of co-occurrence regularities in language to the development of semantic organization

With development knowledge becomes organized according to semantic links, including early-developing associative (e.g., juicy-apple) and gradually developing taxonomic links (e.g., apple-pear). Word co-occurrence regularities may foster these links: Associative links may form from direct co-occurrence (e.g., juicy-apple), and taxonomic links from shared co-occurrence (e.g., apple and pear co-occur with juicy). Four experiments (2017-2020) investigated this possibility with 4- to 8-year-olds (N = 148, 82 female) and adults (N = 116, 35 female) in a U.S. city with 58.6% White; 29.0% Black, and 5.8% Asian demographics. Results revealed earlier development of the abilities to form direct (ds > 0.536) than the abilities to form shared co-occurrence-based links (ds > 1.291). We argue that the asynchronous development of abilities to form co-occurrence-based links may explain developmental changes in semantic organization.

Assessing children’s information and knowledge organisation competency in elementary schools of Hong Kong

This article evaluates the information and knowledge organisation competency of third- to fifth-grade primary school students in Hong Kong directly or indirectly. The majority of the students are aged 8–11 years. The types of information and knowledge organisation schemes to be identified or organised include shallow taxonomies (e.g. a list of entities, a list of features of an entity, a list of events) and simple descriptive ontologies (e.g. a sequence of events, reasons of events, relation between entities or events). A total of 86 students participated in the study. Each student was asked to read an English book and a Chinese book, and to answer assessment questions about the content within the books. The questions ask children to identify members of a flat taxonomy and organise simple descriptive ontologies. The children’s overall information and knowledge organisation competency is found to be weak, but children’s information and knowledge organisation capabilities are not equally weak. The children identify features of an entity significantly better than a list of events, and identify reasons significantly better than flat taxonomies and relations. The findings have theoretical and practical implications for book writers, book cover designers, teachers, librarians and designers of information systems for children.

The representation of emotion knowledge across development

The present study examined how children spontaneously represent facial cues associated with emotion. 106 three‐ to six‐year‐old children (48 male, 58 female; 9.4% Asian, 84.0% White, 6.6% more than one race) and 40 adults (10 male, 30 female; 10% Hispanic, 30% Asian, 2.5% Black, 57.5% White) were recruited from a Midwestern city (2019–2020), and sorted emotion cues in a spatial arrangement method that assesses emotion knowledge without reliance on emotion vocabulary. Using supervised and unsupervised analyses, the study found evidence for continuities and gradual changes in children's emotion knowledge compared to adults. Emotion knowledge develops through an incremental learning process in which children change their representations using combinations of factors—particularly valence—that are weighted differently across development.

Research at a Distance: Replicating Semantic Differentiation Effects Using Remote Data Collection With Children Participants

Remote data collection procedures can strengthen developmental science by addressing current limitations to in-person data collection and helping recruit more diverse and larger samples of participants. Thus, remote data collection opens an opportunity for more equitable and more replicable developmental science. However, it remains an open question whether remote data collection procedures with children participants produce results comparable to those obtained using in-person data collection. This knowledge is critical to integrate results across studies using different data collection procedures. We developed novel web-based versions of two tasks that have been used in prior work with 4-6-year-old children and recruited children who were participating in a virtual enrichment program. We report the first successful remote replication of two key experimental effects that speak to the emergence of structured semantic representations (N = 52) and their role in inferential reasoning (N = 40). We discuss the implications of these findings for using remote data collection with children participants, for maintaining research collaborations with community settings, and for strengthening methodological practices in developmental science.

Development of Conceptual Flexibility in Intuitive Biology: Effects of Environment and Experience

Living things can be classified in many ways, such as taxonomic similarity (lions and lynx), or shared ecological habitat (ducks and turtles). The present studies used card-sorting and triad tasks to explore developmental and experiential changes in conceptual flexibility-the ability to switch between taxonomic and ecological construals of living things-as well as two processes underlying conceptual flexibility: salience (i.e., the ease with which relations come to mind outside of contextual influences) and availability (i.e., the presence of relations in one's mental space) of taxonomic and ecological relations. We were also interested in the extent to which salience and availability of taxonomic and ecological relations predicted inductive inferences. Participants were 452 six to ten-year-olds from urban, suburban, and rural communities in New England. Across two studies, taxonomic relations were overwhelmingly more salient than ecological relations, although salience of ecological relations was higher among children from rural environments (Study 1) and those who engaged in unstructured exploration of nature (Study 2). Availability of ecological relations, as well as conceptual flexibility, increased with age, and was higher among children living in more rural environments. Notably, salience, but not availability, of ecological relations predicted ecological inferences. These findings suggest that taxonomic categories (i.e., groups that share both perceptual similarities and rich underlying structure) are a salient way to organize intuitive biological knowledge and that, critically, environmental richness and relevant experience contribute to the salience and availability of ecological knowledge, and thereby, conceptual flexibility in biological thinking. More generally, they highlight important linkages between domain-specific knowledge and domain-general cognitive abilities.

Lumping and splitting: Developmental changes in the structure of children's semantic networks

Organized semantic representations encoding across- and within-domain distinctions are a hallmark of mature cognition, and understanding how they change with experience and learning is a key endeavor in developmental science. Existing computational modeling studies provide a mechanistic framework for understanding how structured semantic representations emerge as a result of development and learning. However, their predictions remain largely untested in young children, with the existing evidence providing only indirect tests of these predictions. Across two experiments, we provide the first direct examination of a key prediction derived from these computational models-that early in development, broad across-domain distinctions should generally be more strongly represented relative to finer-grained within-domain distinctions. The results support this hypothesis, being consistent with the exploitation of patterns of covariation among entities as a mechanism supporting the acquisition of structured semantic representations.

Experience-Driven Semantic Differentiation: Effects of a Naturalistic Experience on Within- and Across-Domain Differentiation in Children

Organized semantic networks reflecting distinctions within and across domains of knowledge are critical for higher-level cognition. Thus, understanding how semantic structure changes with experience is a fundamental question in developmental science. This study probed changes in semantic structure in 4-6 year-old children (N = 29) as a result of participating in an enrichment program at a local botanical garden. This study presents the first direct evidence that (a) the accumulation of experience with items in a domain promoted increases in both within- and across-domain semantic differentiation, and that (b) this experience-driven semantic differentiation generalized to nonexperienced items. These findings have implications for understanding the role of experience in building semantic networks, and for conceptualizing the contribution of enrichment experiences to academic success.

Relaciones conceptuales: comparación entre Niños, Adultos Jóvenes y Adultos Mayores

El estudio de la organización del conocimiento en la memoria semántica suscita gran interés en Psicología Cognitiva y Neuropsicología. El conocimiento semántico está representado por conceptos que comparten características y forman una jerarquía inclusiva -organización taxonómica-, o que se vinculan en tiempo y espacio -organización temática o situacional-. Se considera que a lo largo del desarrollo cambia la preferencia por estos tipos de organización, pero son pocos los estudios que comparan las organizaciones conceptuales de niños en edad escolar, adultos jóvenes y mayores, y sus resultados son divergentes. Asimismo, la organización conceptual también varía en función del dominio al que pertenece el concepto (vivo vs no vivo). Por lo tanto, el objetivo general de este estudio fue estudiar qué tipos de organización conceptual empleaban esos grupos en una tarea de producción de atributos para conceptos de seres vivos y no vivos. Los resultados indican que la producción de atributos taxonómicos fue significativamente mayor para los adultos jóvenes que para los adultos mayores y los niños, en tanto la producción taxonómica de estos dos últimos grupos fue pareja. En cuanto a la producción temática, fue alta y homogénea en los tres grupos de edad. Por último, para el dominio de los seres no vivos los atributos resultaron en su mayoría temáticos y perceptivos, y para el dominio de los seres vivos, mayormente perceptivos.