The effects of speaker and exemplar variability in children's cross-situational word learning.

Cross-situational word learning (XSWL) - children's ability to learn words by tracking co-occurrence statistics of words and their referents over time - has been identified as a fundamental mechanism underlying lexical learning. However, it is unknown whether children can acquire new words when faced with variable input in XSWL paradigms, such as varying object exemplars and variable speakers. In the present study, we examine the separate and combined effects of exemplar and speaker variability on XSWL in typically developing English-speaking monolingual children. Results revealed that variability in speakers and exemplars did not facilitate or hinder XSWL performance. However, input that varied in both speakers and exemplars simultaneously did hinder children's word learning. Results from this work suggest that XSWL mechanisms may support categorization and generalization beyond word-object associations, but that accommodating multiple forms of variable input may incur costs. Overall, this research provides new theoretical insights into how fundamental mechanisms of word learning scale to more complex and naturalistic forms of input.

Nameability supports rule-based category learning in children and adults.

The present study tested the hypothesis that verbal labels support category induction by providing compact hypotheses. Ninety-seven 4- to 6-year-old children (M = 63.2 months; 46 female, 51 male; 77% White, 8% more than one race, 4% Asian, and 3% Black; tested 2018) and 90 adults (M = 20.1 years; 70 female, 20 male) in the Midwestern United States learned novel categories with features that were easy (e.g., "red") or difficult (e.g., "mauve") to name. Adults (d = 1.06) and-to a lesser extent-children (d = 0.57; final training block) learned categories composed of more nameable features better. Children's knowledge of difficult-to-name color words predicted their learning for categories with difficult-to-name features. Rule-based category learning may be supported by the emerging ability to form verbal hypotheses.

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.

Does the public know what researchers know? Perceived task difficulty impacts adults' intuitions about children's early word learning.

The present study examined adults' understanding of children's early word learning. Undergraduates, non-parents, parents, and Speech-Language Pathologists (N = 535, 74% female, 56% White) completed a survey with 11 word learning principles from the perspective of a preschooler. Questions tested key principles from early word learning research. For each question, participants were prompted to select an answer based on the perspective of a preschooler. Adults demonstrated aligned intuitions for all principles except those derived from domain-general theories, regardless of experience with language development (Experiment 1). Experiment 2 revealed that perceived difficulty of a task for a preschooler impacted adults' reasoning about word learning processes. Experiment 3 ruled out level of confidence and interest as mechanisms to explain the results. These results highlight disconnects in knowledge between the cognitive development research community and the general public. Therefore, efforts must be made to communicate scientific findings to the broader non-academic community, emphasizing children's ability to excel at word learning in the face of task difficulty.

The effects of bilingualism on children's cross-situational word learning under different variability conditions.

In the current study, we examined the separate and combined effects of exemplar and speaker variability on monolingual and bilingual children's cross-situational word learning performance. Results revealed that children's word learning performance did not differ when the input varied in a single dimension (i.e., exemplars or speakers) compared with a condition with no variability independent of their linguistic background. However, when performance in conditions that varied in a single dimension (i.e., exemplars or speakers) was compared with a condition that varied in multiple dimensions (i.e., exemplars and speakers), bilingual word learning advantages were observed; bilinguals were more likely to learn word-referent associations than monolinguals. Together, results suggest that children can learn and generalize word-referent associations from input that varies in exemplars and speakers and that bilingualism may bolster learning under conditions of increased input variability.

Not all is forgotten: Children's associative matrices for features of a word learning episode.

Word learning studies traditionally examine the narrow link between words and objects, indifferent to the rich contextual information surrounding objects. This research examined whether children attend to this contextual information and construct an associative matrix of the words, objects, people, and environmental context during word learning. In Experiment 1, preschool-aged children (age: 3;2-5;11 years) were presented with novel words and objects in an animated storybook. Results revealed that children constructed associations beyond words and objects. Specifically, children attended to and had the strongest associations for features of the environmental context but failed to learn word-object associations. Experiment 2 demonstrated that children (age: 3;0-5;8 years) leveraged strong associations for the person and environmental context to support word-object mapping. This work demonstrates that children are especially sensitive to the word learning context and use associative matrices to support word mapping. Indeed, this research suggests associative matrices of the environment may be foundational for children's vocabulary development.

"What makes this a wug?" Relations among children's question asking, memory, and categorization of objects.

Children ask many questions, but do not always receive answers to the questions they ask. We were interested in whether the act of generating questions, in the absence of an answer, is related to children's later thinking. Two experiments examined whether children retain the questions they ask in working memory, and whether the type of questions asked relate to their categorization. Four to ten-year-old children (N = 42 in Experiment 1, N = 41 in Experiment 2) were shown 12 novel objects, asked three questions about each, and did not receive answers to their questions. Children recalled their questions in the first experiment and categorized variants of the novel objects in the second experiment. We found that children have robust working memory for their questions, indicating that these questions may relate to their subsequent thinking. Additionally, children generalize category boundaries more narrowly or broadly depending on the type of question they ask, indicating that children's questions may reflect an underlying bias in how they think about the world. These findings suggest that future research should examine questions in the absence of answers to understand how inquiry affects children's cognitive development.

Children's knowledge of superordinate words predicts subsequent inductive reasoning.

Children's early language knowledge-typically assessed using standardized word comprehension tests or through parental reports-has been positively linked to a variety of later outcomes, from reasoning tests to academic performance to income and health. To better understand the mechanisms behind these links, we examined whether knowledge of certain "seed words"-words with high inductive potential-is positively associated with inductive reasoning. This hypothesis stems from prior work on the effects of language on categorization suggesting that certain words may be important for helping people to deploy categorical hypotheses. Using a longitudinal design, we assessed 36 2- to 4-year-old children's knowledge of 333 words of varying levels of generality (e.g., toy vs. pinwheel, number vs. five). We predicted that adjusting for overall vocabulary, knowledge of more general words (e.g., toy, number) would predict children's performance on inductive reasoning tasks administered 6 months later (i.e., a subset of the Stanford-Binet Intelligence Scales for Early Childhood-Fifth Edition [SB-5] and Woodcock-Johnson Tests of Cognitive Abilities [WJ] concept formation tasks). This prediction was confirmed for one of the measures of inductive reasoning (i.e., the SB-5 but not the WJ) and notably for the task considered to be less reliant on language. Although our experimental design demonstrates only a correlational relationship between seed word knowledge and inductive reasoning ability, our results are consistent with the possibility that early knowledge of certain seed words facilitates performance on putatively nonverbal reasoning tasks.

Children's science vocabulary uniquely predicts individual differences in science knowledge.

Science achievement gaps are a persistent social issue and are largely explained by individual differences in science knowledge before formal schooling. We were interested in whether children's science vocabulary relates to these differences in science knowledge. This experiment examined whether children's science vocabulary predicted their science knowledge above and beyond general vocabulary size and demographic variables. Children aged 3 to 11 years (N = 91; 59 boys) participated in-person at a laboratory within a large university in a mid-size city in the midwestern United States. The tasks that the children completed assessed general receptive vocabulary, science productive vocabulary, general science knowledge, and conceptions of science as a practice. We found that science vocabulary was the strongest predictor of science knowledge above and beyond other factors, indicating that science vocabulary production may predict individual differences in science knowledge specifically when achievement gaps emerge (ß = .28). In addition, children who produced more of certain types of science words, such as size and physical property words, depicted more science equipment and language elements in their drawings of scientists. These findings suggest that learning new words may be related to conceptual development in science and that examining early science vocabulary is a key step toward fully understanding science knowledge gaps.

Lexical access speed and the development of phonological recoding during immediate serial recall.

A recent Registered Replication Report (RRR) of the development of verbal rehearsal during serial recall (Elliott et al., 2021) revealed that children verbalized at younger ages than previously thought (Flavell et al., 1966), but did not identify sources of individual differences. Here we use mediation analysis to reanalyze data from the 934 children ranging from 5 to 10 years old from the RRR for that purpose. From ages 5 to 7, the time taken for a child to label pictures (i.e. isolated naming speed) predicted the child's spontaneous use of labels during a visually-presented serial reconstruction task, despite no need for spoken responses. For 6- and 7-year-olds, isolated naming speed also predicted recall. The degree to which verbalization mediated the relation between isolated naming speed and recall changed across development. All relations dissipated by age 10. The same general pattern was observed in an exploratory analysis of delayed recall for which greater demands are placed on rehearsal for item maintenance. Overall, our findings suggest that spontaneous phonological recoding during a standard short-term memory task emerges around age 5, increases in efficiency during the early elementary school years, and is sufficiently automatic by age 10 to support immediate serial recall in most children. Moreover, the findings highlight the need to distinguish between phonological recoding and rehearsal in developmental studies of short-term memory.

Where's the Advantage? Mutual Exclusivity Promotes Children's Initial Mapping, but Not Long-Term Memory, for Words Compared to Other Strategies.

Children frequently apply a novel label to a novel object, a behavior known as the mutual exclusivity bias (MEB). This study examined how MEB affects children's retention for word mappings. In Experiment 1, preschoolers (N = 39; M age = 46.62 months) and adults (N = 24; M age = 21.63 years) completed an immediate word mapping task and a delayed retention test. Both samples used MEB during referent selection, but neither group displayed higher retention for words mapped via MEB than words mapped via other referent selection strategies at test. Experiment 2 replicated Experiment 1 with preschoolers (N = 85; M age = 47.78 months) and provided evidence against the possibility that interference from multiple words contributed to children's faster forgetting of word mappings when using MEB. Experiment 3 presented children (N = 30; M age = 51.13 months) with an abbreviated version of the task, providing evidence against the alternative hypothesis that cognitive load during learning caused the forgetting observed in Experiments 1 and 2. Taken together, these experiments suggest that MEB supports initial word mapping but may not provide an advantage for long-term retention.

Cross-Situational Learning of Phonologically Overlapping Words Across Degrees of Ambiguity.

Cross-situational word learning (XSWL) tasks present multiple words and candidate referents within a learning trial such that word-referent pairings can be inferred only across trials. Adults encode fine phonological detail when two words and candidate referents are presented in each learning trial (2 × 2 scenario; Escudero, Mulak, & Vlach, ). To test the relationship between XSWL task difficulty and phonological encoding, we examined XSWL of words differing by one vowel or consonant across degrees of within-learning trial ambiguity (1 × 1 to 4 × 4). Word identification was assessed alongside three distractors. Adults finely encoded words via XSWL: Learning occurred in all conditions, though accuracy decreased across the 1 × 1 to 3 × 3 conditions. Accuracy was highest for the 1 × 1 condition, suggesting fast-mapping is a stronger learning strategy here. Accuracy was higher for consonant than vowel set targets, and having more distractors from the same set mitigated identification of vowel set targets only, suggesting possible stronger encoding of consonants than vowels.

To mass or space? Young children do not possess adults' incorrect biases about spaced learning.

The spacing effect is the robust finding that learners have stronger long-term memory for information presented on a spaced schedule, in which learning events are distributed across time, rather than a massed schedule, in which learning events are presented in immediate succession. Despite the fact that the spacing effect is highly replicable across tasks and timescales, most adults do not believe that spaced learning promotes memory. Instead, there is a persistent "massed bias"; adults believe that massed learning promotes memory to a greater degree than spaced learning. The developmental origins of the massed bias have yet to be studied; thus, the goals of the current research were to (a) identify a developmental period in which we do not observe a massed bias and (b) determine whether metamemory is related to the onset of the massed bias. The results revealed that children (aged 2-10 years; N = 109) do not have a persistent massed bias, and the number of massed endorsements increased across the early elementary school years. Children's age predicted a massed bias, but individual differences in children's metamemory abilities were not related to bias development when controlling for age. Taken together, this work suggests that researchers will need to reconceptualize dual-process theoretical accounts of metamemory and spaced learning to explain why and how children develop a massed bias.

Statistics learned are statistics forgotten: Children's retention and retrieval of cross-situational word learning.

Children are able to resolve the referential ambiguity of learning new words by tracking co-occurrence probabilities across moments in time, a behavior termed cross-situational word learning (CSWL). Although we know that children can use co-occurrence data to map words to objects, the literature has a striking limitation: research has focused on encoding of language and, consequently, children's CSWL has only been assessed at an immediate test. The current research addressed this gap in the literature by examining whether children can retain and retrieve learned words after a retention interval, and whether children's age and individual cognitive abilities contribute to their CSWL performance. The results revealed that children were able to retain and retrieve co-occurrence statistics, but only reliably so at the end of early childhood. Moreover, children's visual recognition memory abilities and the timing of learning events were the two key factors that contributed to children's performance. These findings have implications for theories and computational models of CSWL, and suggest that more research is needed to understand the processes that support CSWL after encoding. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Remember dax? Relations between children's cross-situational word learning, memory, and language abilities.

Learning new words is a difficult task. Children are able to resolve the ambiguity of the task and map words to referents by tracking co-occurrence probabilities across multiple moments in time, a behavior termed cross-situational word learning (CSWL). Although we observe developments in CSWL abilities across childhood, the cognitive processes that drive individual and developmental change have yet to be identified. This research tested a developmental systems account by examining whether multiple cognitive systems co-contribute to children's CSWL. The results of two experiments revealed that multiple cognitive domains, such as memory and language abilities, are likely to drive the development of CSWL above and beyond children's age. The results also revealed that memory abilities are likely to be particularly important above and beyond other cognitive abilities. These findings have implications for theories and computational models of CSWL, which typically do not account for individual children's cognitive capacities or changes in cognitive capacities across time.

Producing Spatial Words Is Not Enough: Understanding the Relation Between Language and Spatial Cognition.

Prior research has investigated the relation between children's language and spatial cognition by assessing the quantity of children's spatial word production, with limited attention to the context in which children use such words. This study tested whether 4-year-olds children's (N = 41, primarily white middle class) adaptive use of task-relevant language across contexts predicted their spatial skills. Children were presented with a spatial scene description task, four spatial tasks, and vocabulary assessments. Children's adaptive use of task-relevant language was more predictive of their spatial skills than demographic and language factors (e.g., quantity of spatial words produced). These findings identify new links between language and spatial cognition and highlight the importance of understanding the quality, not just quantity, of children's language use.

Infants Encode Phonetic Detail during Cross-Situational Word Learning.

Infants often hear new words in the context of more than one candidate referent. In cross-situational word learning (XSWL), word-object mappings are determined by tracking co-occurrences of words and candidate referents across multiple learning events. Research demonstrates that infants can learn words in XSWL paradigms, suggesting that it is a viable model of real-world word learning. However, these studies have all presented infants with words that have no or minimal phonological overlap (e.g., BLICKET and GAX). Words often contain some degree of phonological overlap, and it is unknown whether infants can simultaneously encode fine phonological detail while learning words via XSWL. We tested 12-, 15-, 17-, and 20-month-olds' XSWL of eight words that, when paired, formed non-minimal pairs (MPs; e.g., BON-DEET) or MPs (e.g., BON-TON, DEET-DIT). The results demonstrated that infants are able to learn word-object mappings and encode them with sufficient phonetic detail as to identify words in both non-minimal and MP contexts. Thus, this work suggests that infants are able to simultaneously discriminate phonetic differences between words and map words to referents in an implicit learning paradigm such as XSWL.

How we categorize objects is related to how we remember them: The shape bias as a memory bias.

The "shape bias" describes the phenomenon that, after a certain point in development, children and adults generalize object categories based on shape to a greater degree than other perceptual features. The focus of research on the shape bias has been to examine the types of information that learners attend to in one moment in time. The current work takes a different approach by examining whether learners' categorical biases are related to their retention of information across time. In three experiments, children's (N=72) and adults' (N=240) memory performance for features of objects was examined in relation to their categorical biases. The results of these experiments demonstrated that the number of shape matches chosen during the shape bias task significantly predicted shape memory. Moreover, children and adults with a shape bias were more likely to remember the shape of objects than the color and size of objects. Taken together, this work suggests that the development of a shape bias may engender better memory for shape information.

Cross-Situational Learning of Minimal Word Pairs.

Cross-situational statistical learning of words involves tracking co-occurrences of auditory words and objects across time to infer word-referent mappings. Previous research has demonstrated that learners can infer referents across sets of very phonologically distinct words (e.g., WUG, DAX), but it remains unknown whether learners can encode fine phonological differences during cross-situational statistical learning. This study examined learners' cross-situational statistical learning of minimal pairs that differed on one consonant segment (e.g., BON-TON), minimal pairs that differed on one vowel segment (e.g., DEET-DIT), and non-minimal pairs that differed on two or three segments (e.g., BON-DEET). Learners performed above chance for all pairs, but performed worse on vowel minimal pairs than on consonant minimal pairs or non-minimal pairs. These findings demonstrate that learners can encode fine phonetic detail while tracking word-referent co-occurrence probabilities, but they suggest that phonological encoding may be weaker for vowels than for consonants.

Temporal dynamics of categorization: forgetting as the basis of abstraction and generalization.

Historically, models of categorization have focused on how learners track frequencies and co-occurrence information to abstract relevant category features for generalization. The current study takes a different approach by examining how the temporal dynamics of categorization affect abstraction and generalization. In the learning phase of the experiment, all relevant category features were presented an equal number of times across category exemplars. However, the relevant features were presented on one of two learning schedules: massed or interleaved. At a series of immediate and delayed tests, learners were asked to generalize to novel exemplars that contained massed features, interleaved features, or all novel features. The results of this experiment revealed that, at an immediate test, learners more readily generalized based upon features presented on a massed schedule. Conversely, at a delayed test, learners more readily generalized based upon features presented on an interleaved schedule, until information was no longer readily retrievable from memory. These findings suggest that forgetting and retrieval processes engendered by the temporal dynamics of learning are used as a basis of abstraction, implicating forgetting as a central mechanism of generalization.