Selective attention allows adults to preferentially exploit input relevant to their goals. One critical role of selective attention is in adult category learning: adults can simplify the entities they encounter into groups of entities that they can treat as equivalent by focusing on category-relevant attributes, while filtering out category-irrelevant attributes. However, much category learning takes place during development, when selective attention substantially matures. We designed two experiments to disentangle the contributions of the focusing and filtering aspects of selective attention to category learning over development. Experiment 1 provided evidence that learning simple categories was accompanied by selective attention in both four year-old and five year-old children and adults. Experiment 2 further provided evidence that only focusing contributed to selective attention in four year-olds, whereas both focusing and filtering contributed to selective attention in five year-olds and adults. Thus, category learning recruits different aspects of selective attention with development.

Often the only source of information for learning a word is its surrounding language context. For example, even without seeing a rambutan, one can learn that it is a fruit just from hearing “I like sweet, juicy rambutans”. What processes foster learning words from context? We investigated candidate processes that can unfold when the context precedes a new word and can foster learning via prediction, versus when the context occurs after and can only be used retroactively. We particularly sought to illuminate a role for working memory in linking a new word to the meaning implied by its context. Experiment 1 probed word learning during reading with eye tracking, and Experiment 2 probed word learning from speech. We found convergent evidence that regardless of whether the context precedes or follows a new word, word learning depends on maintaining the context in working memory while linking it to a new word.

Prior evidence suggests that category learning can occur implicitly by detecting regular co-occurrences of features within categories. Less studied is whether regularities wherein category membership predicts other events or actions also foster category learning. Moreover, we know little about whether, and to what degree, exposure to these regularities facilitates subsequent supervised learning. Here, participants were pre-exposed to exemplars from two categories during a cover task, while uninformed of their category membership. Pre-exposure occurred under conditions in which category membership did (Predictive Mapping) or did not (Mere Exposure) predict task events to which participants responded. Baseline participants completed the same task with category- irrelevant stimuli. Subsequently, all participants were taught the categories (using pre-exposure exemplars) under explicit supervision. Whereas neither Predictive Mapping nor Mere Exposure influenced cover task performance (vs. Baseline), Predictive Mapping substantially improved subsequent supervised category learning. These findings point to latent category learning given pre-exposure to Predictive Mapping regularities.

Extensive findings attest to an early-emerging sensitivity to statistical regularities, such as reliable co-occurrence betweenperceptual inputs. However, we know little about how such sensitivity may shape the organization of semantic memoryaccording to relations between concepts. To address this question, we designed a paradigm appropriate for a broad devel-opmental age-range in which participants identify whether either a word or a picture is the same or of the same thing as apreceding word (e.g., chicken followed by chicken or a chicken picture). Semantic effects are inferred from slower correctno responses to pairs that are related versus those that are unrelated. We used this paradigm to assess semantic effects in4-year-old children for pairs that co-occurred in child-directed speech (e.g., shoe-foot) or were taxonomically related (e.g.,fork-bowl). We found evidence of semantic effects in all conditions, suggesting that co-occurrence sensitivity contributesto relational knowledge in emerging semantic networks.

Accounts of induction development suggest that young children’s inferences are based either on object kind knowledge (Gelman & Markman, 1986), or on perceptual similarity (e.g., Sloutsky & Fisher, 2004). However, both accounts suggest that inferences with familiar and newly-learned categories engage a common set of psychological processes (determination of object kind or perceptual similarity). Alternately, young children may perform similarity-based induction with newly-learned categories, but use prior knowledge to make inferences with familiar categories. In this study, children complete two versions of a task in which a property attributed to a target can be extended to a category match or a perceptual match. In one version, items belong to familiar biological categories; in the other, items belong to two novel pseudo-biological categories. Preliminary findings indicate that although Kindergarten-age children learn to accurately categorize the novel items, they make similarity-based inferences with newly-learned categories, and category-consistent inferences with familiar categories.

The roles of semantic and perceptual information in cognition are of widespread interest to many researchers. However, disentangling their contributions is complicated by their overlap in real-world categories. For instance, attempts to calibrate visual similarity based on participant judgments are undermined by the possibility that semantic knowledge contaminates these judgments. This study investigated whether inverting stimuli attenuates semantic contamination of visual similarity judgments in adults and children. Participants viewed upright and inverted triads of familiar animals, and judged which of two test items looked most like the target. One test item belonged to the same category as the target, and one belonged to a different category. Test items’ visual similarity to the target either corresponded or conflicted with category membership. Across age groups, conflicting category membership reduced accuracy and slowed reaction times to a greater extent in upright than inverted triads. Therefore, inversion attenuates semantic contamination of visual similarity judgments.

The organization of knowledge according to relations between concepts is critically involved in many cognitive processes, including memory and reasoning. However, the role of learning in shaping knowledge organization has received little direct investigation. Therefore, the present study investigated whether informal learning experiences can drive rapid, substantial changes in knowledge organization in children by measuring the effects of a week-long Zoo summer camp versus a control camp on the degree to which 4- to 9-year-old children’s knowledge about animals was organized according to taxonomic relations. Although taxonomic organization did not differ at pre-test, only Zoo camp children showed increases in taxonomic organization at post-test. These findings provide novel evidence that informal, real-life learning experiences can drive rapid knowledge organization change.

Sensitivity to statistical co-occurrence regularities is present from infancy. This sensitivity may contribute to learning in many domains, including category learning. However, prior research has not examined whether everyday input conveys category-relevant statistical regularities. This study assessed whether statistical regularities relevant to real-world categories are present in a commonly experienced source input – children’s picture books. We focused on animal categories because this is a domain in which children receive much exposure from an early age, while simultaneously holding persistent misconceptions about category membership beyond preschool years. Analysis of 80 books revealed that they: 1) Were likely to contain regularities from which individual species categories (e.g., “chicken”) might be learned, but 2) Were unlikely to contain regularities from which broader taxonomic categories (e.g., “bird”) might be learned. These findings point to a paucity of taxonomically-relevant statistical regularities that may contribute to persistent taxonomic misconceptions.

The organization of semantic knowledge according to relations between concepts influences many facets of highercognition. Therefore, understanding the origins of relations knowledge is a key focus of cognitive development research. Thisstudy investigated the contributions of environmental statistical regularities to relations knowledge in preschool-age children.Using CHILDES to estimate co-occurrence between familiar items, we constructed triads consisting of a target, related distrac-tor, and unrelated distractor in which targets and related distractors consistently co-occurred (e.g., sock-foot), belonged to thesame taxonomic category (e.g., sock-coat), or both (e.g., sock-shoe). Using a Visual World paradigm, we then measured rela-tions knowledge as the degree to which children looked at related versus unrelated distractors when asked to look for targets.The results revealed that co-occurrence, regardless of taxonomic relatedness, influenced whether participants looked signifi-cantly more at related versus unrelated distractors. These findings demonstrate that co-occurrence regularities between entitiesin the environment shape knowledge organization.

Many hallmarks of human intelligence including language, reasoning, and planning require us to draw upon knowledge about the world in which concepts, denoted by words, are organized by meaningful, semantic links between them (e.g., juicy-apple-pear). The goal of the present research was to investigate how these organized semantic networks may emerge in development from simple but powerful mechanisms sensitive to statistical co- occurrence regularities of word use in language. Specifically, we tested whether a mechanistic account of how co-occurrence regularities shape semantic development accurately predicts how semantic organization changes with development. Using a sensitive, gaze-based measure of the semantic links organizing knowledge in children and adults, we observed that developmental changes in semantic organization were consistent with a key role for statistical co-occurrence regularities.