Predictable Events Enhance Word Learning in Toddlers

Integrating developmental neuroscience with community-engaged approaches to address mental health outcomes for housing-insecure youth: Implications for research, practice, and policy

One in three children in the United States is exposed to insecure housing conditions, including unaffordable, inconsistent, and unsafe housing. These exposures have detrimental impacts on youth mental health. Delineating the neurobehavioral pathways linking exposure to housing insecurity with children's mental health has the potential to inform interventions and policy. However, in approaching this work, carefully considering the lived experiences of youth and families is essential to translating scientific discovery to improve health outcomes in an equitable and representative way. In the current paper, we provide an introduction to the range of stressful experiences that children may face when exposed to insecure housing conditions. Next, we highlight findings from the early-life stress literature regarding the potential neurobehavioral consequences of insecure housing, focusing on how unpredictability is associated with the neural circuitry supporting cognitive and emotional development. We then delineate how community-engaged research (CEnR) approaches have been leveraged to understand the effects of housing insecurity on mental health, and we propose future research directions that integrate developmental neuroscience research and CEnR approaches to maximize the impact of this work. We conclude by outlining practice and policy recommendations that aim to improve the mental health of children exposed to insecure housing.

Early word learning is influenced by physical environments

During word learning moments, toddlers experience labels and objects in particular environments. Do toddlers learn words better when the physical environment creates contrasts between objects with different labels? Thirty-six 21- to 24-month-olds (92% White, 22 female, data collected 8/21-4/22) learned novel words for novel objects presented using an apparatus that mimicked a shape-sorter toy. The manipulation concerned whether or not the physical features of the environments in which objects occurred heightened the contrasts between the objects. Toddlers only learned labels for objects presented in environments where the apparatus heightened the contrast between the objects (b = .068). These results emphasize the importance of investigating word learning in physical environments that more closely approximate young children's everyday experiences with objects.

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.

The electrophysiological correlates of word pre-activation during associative word learning

Human beings continuously make use of learned associations to generate predictions about future occurrences in the environment. Such memory-related predictive processes provide a scaffold for learning in that mental representations of foreseeable events can be adjusted or strengthened based on a specific outcome. Learning the meaning of novel words through picture-word associations constitutes a prime example of associative learning because pictures preceding words can trigger word prediction through the pre-activation of the related mnemonic representations. In the present electroencephalography (EEG) study, we used event-related potentials (ERPs) to compare neural indices of word pre-activation between a word learning condition with maximal prediction likelihood and a non-learning control condition with low prediction. Results revealed that prediction-related N400 amplitudes in response to pictures decreased over time at central electrodes as a function of word learning, whereas late positive component (LPC) amplitudes increased. Notably, N400 but not LPC changes were also predictive of word learning performance, suggesting that the N400 component constitutes a sensitive marker of word pre-activation during associative word learning.

Acquiring Complex Communicative Systems: Statistical Learning of Language and Emotion

During the early postnatal years, most infants rapidly learn to understand two naturally evolved communication systems: language and emotion. While these two domains include different types of content knowledge, it is possible that similar learning processes subserve their acquisition. In this review, we compare the learnable statistical regularities in language and emotion input. We then consider how domain-general learning abilities may underly the acquisition of language and emotion, and how this process may be constrained in each domain. This comparative developmental approach can advance our understanding of how humans learn to communicate with others.

How Many Palabras? Codeswitching and Lexical Diversity in Spanish-English Picture Books

Bilingual picture books have been growing in popularity, with caregivers, teachers, and researchers increasingly interested in understanding how picture books might be able to support the learning of words in two languages. In this study, we present the first evaluation of the quantity and quality of text contained within bilingual picture books in English and Spanish targeted to children ages 0–9 and available to parents in the United States. We focus specifically on a sample of codeswitching books (N = 45) which present text in one language embedded in another language. All books were transcribed and evaluated for (1) the number of words and utterances presented in each language; (2) the quality and complexity of text presented in each language; and (3) how switching occurred between the two languages. Results showed that although picture books in our sample presented predominantly English text and more complex English sentences, relatively more unique words were presented in Spanish. Furthermore, picture books in our sample presented frequent switching between languages, particularly within utterances. We suggest that bilingual picture books provide children with potentially enriching yet asymmetrical opportunities for learning in each language.

Cognitive and metacognitive, motivational, and resource considerations for learning new skills across the lifespan

Across the lifespan, learners have to tackle the challenges of learning new skills. These skills can range from abilities needed for survival, such as learning languages, learning to walk during infancy, and learning new software for a job in adulthood, to abilities related to leisure and hobbies. As the learner progresses through novice to expert stages, there are cognitive and metacognitive, motivational, and resource considerations for learning new skills. In terms of cognitive considerations, fluid and crystallized abilities as well as executive functions interact to help the learner process and retain information related to the skills. In terms of metacognitive considerations, knowing what to learn and how to learn are important for novel skill learning. In terms of motivational considerations, changes in individuals' intrinsic and extrinsic motivation throughout the lifespan impact their pursuit of novel skill learning, and declines in motivation can be buffered through the cultivation of grit, growth mindset, self-efficacy, and other personal factors. In terms of resource considerations, there are many tools that learners can use to acquire new skills, but allocation and availability of these resources differ based on life stage and socioeconomic status. Taken together, these considerations may provide learners with the best chance at acquiring new skills across the lifespan. Further research investigating these three factors, particularly among older adult learners, and their interactive effects could help increase our understanding of their impacts on skill learning and inform future cognitive interventions that can be tailored to learners' unique needs. This article is categorized under: Cognitive Biology > Cognitive Development Psychology > Development and Aging Psychology > Learning.

The Origins of Social Knowledge in Altricial Species

Human infants are altricial, born relatively helpless and dependent on parental care for an extended period of time. This protracted time to maturity is typically regarded as a necessary epiphenomenon of evolving and developing large brains. We argue that extended altriciality is itself adaptive, as a prolonged necessity for parental care allows extensive social learning to take place. Human adults possess a suite of complex social skills, such as language, empathy, morality, and theory of mind. Rather than requiring hardwired, innate knowledge of social abilities, evolution has outsourced the necessary information to parents. Critical information for species-typical development, such as species recognition, may originate from adults rather than from genes, aided by underlying perceptual biases for attending to social stimuli and capacities for statistical learning of social actions. We draw on extensive comparative findings to illustrate that, across species, altriciality functions as an adaptation for social learning from caregivers.

Prediction error boosts retention of novel words in adults but not in children

How do we update our linguistic knowledge? In seven experiments, we asked whether error-driven learning can explain under what circumstances adults and children are more likely to store and retain a new word meaning. Participants were exposed to novel object labels in the context of more or less constraining sentences or visual contexts. Both two-to-four-year-olds (M_age = 38 months) and adults were strongly affected by expectations based on sentence constraint when choosing the referent of a new label. In addition, adults formed stronger memory traces for novel words that violated a stronger prior expectation. However, preschoolers' memory was unaffected by the strength of their prior expectations. We conclude that the encoding of new word-object associations in memory is affected by prediction error in adults, but not in preschoolers.

The temporal structure of naming events differentially affects children's and adults' cross-situational word learning

To acquire novel words, learners often need to integrate information about word meanings across ambiguous learning events distributed in time. How does the temporal structure of those word learning events affect what learners encode? How do the effects of temporal structure differ in children and adults? In the current experiments, we asked how 4- to 7-year-old children's (N = 110) and adults' (N = 90) performance on a cross-situational word learning task is influenced by the temporal distribution of learning events. We tested participants in three training conditions, manipulating the number of trials that separated naming events for specific objects. In the Unstructured condition, the temporal distribution was varied; in the Massed condition, naming events occurred with few interleaved trials; and in the Interleaved condition, naming events occurred with many interleaved trials. Adults showed substantially larger benefits from the Massed condition than children, whereas children were equally successful at learning in the Massed and Interleaved conditions. These results provide evidence that adults differ from children in how they exploit temporal structure during cross-situational word learning.

The developing predictive brain: How implicit temporal expectancy induced by local and global prediction shapes action preparation across development

Human behavior is continuously shaped not just as a function of explicitly responding to external world events but also by internal biases implicitly driven by the capacity to extract statistics from complex sensory patterns. Two possible sources of predictability engaged to generate and update temporal expectancy are the implicit extraction of either local or global statistical contingencies in the events' temporal structure. In the context of action preparation the local prediction has been reported to be stable from the age of 6. However, there is no evidence about how the ability to extract and use global statistical patterns to establish temporal expectancy changes across development. Here we used a new, child-friendly reaction time task purposely designed to investigate how local (within-trial expectancy bias) and global (between-block expectancy bias) prediction interplay to generate temporal expectancy and consequently shape action preparation in young (5- to 6-year-old), middle-aged (7- to 8-year-old) and old (9- to 10-year-old) typically developing children. We found that while local temporal prediction showed stable developmental trajectories, the ability to use a global rule to action preparation in terms of both accuracy and speed becomes stable after the age of seven. These findings are discussed by adopting a neuroconstructivist-inspired theoretical account, according to which the developmental constraints on learning from hierarchically nested levels of sensory complexity may constitute a necessary prerequisite for mastering complex domains.

Statistical language learning in infancy

Research to date suggests that infants exploit statistical regularities in linguistic input to identify and learn a range of linguistic structures, ranging from the sounds of language (e.g., native-language speech sounds, word boundaries in continuous speech) to aspects of grammatical structure (e.g., lexical categories like nouns and verbs, basic aspects of syntax). This article presents a brief review of the infant statistical language learning literature, and raises broader questions concerning why infants are sensitive to statistical regularities. In doing so, we consider the relationship between statistical learning, prediction, and uncertainty reduction in infancy.

Learning What to Learn Across the Life Span: From Objects to Real-World Skills

One of the most difficult and important problems that all learners face across the life span is learning what to learn. Understanding what to learn is difficult when both relevant and irrelevant information compete for attention. In these situations, the learner can rely on cues in the environment, as well as prior knowledge. However, these sources of information sometimes conflict, and the learner has to prioritize some sources over others. Determining what to learn is important because learning relevant information helps the learner achieve goals, whereas learning irrelevant information can waste time and energy. A new theoretical approach posits that adaptation is relevant for all age groups because the environment is dynamic, suggesting that learning what to learn is a problem relevant across the life span instead of only during infancy and childhood. In this article, I review new research demonstrating the importance and ways of learning what to learn across the life span, from objects to real-world skills, before highlighting some unresolved issues for future research.

Non-Linguistic Grammar Learning by 12-Month-Old Infants: Evidence for Constraints on Learning

Infants acquiring their native language are adept at discovering grammatical patterns. However, it remains unknown whether these learning abilities are limited to language, or available more generally for sequenced input. The current study is a conceptual replication of a prior language study, and was designed to ask whether infants can track phrase structure-like patterns from nonlinguistic auditory materials (sequences of computer alert sounds). One group of 12-month-olds was familiarized with an artificial grammar including predictive dependencies between sounds concatenated into strings, simulating the basic structure of phrases in natural languages. A second group of infants was familiarized with a grammar that lacked predictive dependencies. All infants were tested on the same set of familiar strings vs. novel (grammar-inconsistent) strings. Only infants exposed to the materials containing predictive dependencies showed successful discrimination between the test sentences, replicating the results from linguistic materials, and suggesting that predictive dependencies facilitate learning from nonlinguistic input.

Violations of Core Knowledge Shape Early Learning

Research on cognitive development has revealed that even the youngest minds detect and respond to events that adults find surprising. These surprise responses suggest that infants have a basic set of "core" expectations about the world that are shared with adults and other species. However, little work has asked what purpose these surprise responses serve. Here we discuss recent evidence that violations of core knowledge offer special opportunities for learning. Infants and young children make predictions about the world on the basis of their core knowledge of objects, quantities, and social entities. We argue that when these predictions fail to match the observed data, infants and children experience an enhanced drive to seek and retain new information. This impact of surprise on learning is not equipotent. Instead, it is directed to entities that are relevant to the surprise itself; this drive propels children-even infants-to form and test new hypotheses about surprising aspects of the world. We briefly consider similarities and differences between these recent findings with infants and children, on the one hand, and findings on prediction errors in humans and non-human animals, on the other. These comparisons raise open questions that require continued inquiry, but suggest that considering phenomena across species, ages, kinds of surprise, and types of learning will ultimately help to clarify how surprise shapes thought.