Word learning emerges from the interaction of online referent selection and slow associative learning

Cross-modal digit span and vocabulary proficiency in deaf or hard-of-hearing children

This study aims to examine the relationship between vocabulary proficiency and short-term memory capacity in deaf or hard-of-hearing (DHH) children. We test the hypothesis that the relationship between vocabulary skills and digit span performance could be strengthened when the digit span task encompasses cross-modal integration processes. A group of DHH children performed two types of auditory digit span tasks. Furthermore, they participated in a standardized vocabulary proficiency test, comprising two subtests: Receptive Vocabulary and Expressive Vocabulary. The verbal digit span served as a significant predictor of Expressive Vocabulary among the DHH children. Simultaneously, the auditory-pointing digit span accounted for a substantial portion of performance variation in both Receptive and Expressive Vocabulary. After considering the impact of the duration of auditory-verbal intervention through regression models, likelihood ratio tests demonstrated that the auditory-pointing digit span persisted as a significant determinant of both receptive and expressive vocabulary skills. A positive influence of the intervention was also confirmed by the present results. This study provides evidence that memory span and the ability to integrate cross-modal information could serve as significant cognitive correlates of vocabulary proficiency in DHH children.

I remembered the chorm! Word learning abilities of children with and without phonological impairment

BACKGROUND

Children with phonological impairment present with pattern-based errors in their speech production. While some children have difficulties with speech perception and/or the establishment of robust underlying phonological representations, the nature of phonological impairment in children is still not well understood. Given that phonological and lexical development are closely linked, one way to better understand the nature of the problem in phonological impairment is to examine word learning abilities in children.

AIMS

To examine word learning and its relationship with speech perception, speech production and vocabulary knowledge in children aged 4-5 years. There were two variables of interest: speech production abilities ranging from phonological impairment to typical speech; and vocabulary abilities ranging from typical to above average ('lexically precocious').

METHODS & PROCEDURES

Participants were 49 Australian-English-speaking children aged 48-69 months. Children were each taught four novel non-words (out of a selection of eight) through stories, and word learning was assessed at 1 week post-initial exposure. Word learning was assessed using two measures: confrontation naming and story retell naming. Data were analysed by group using independent-samples t-tests and Mann-Whitney U-tests, and continuously using multiple linear regression.

OUTCOMES & RESULTS

There was no significant difference in word learning ability of children with and without phonological impairment, but regardless of speech group, children with above average vocabulary had significantly better word learning abilities than children with average vocabulary. In multiple linear regression, vocabulary was the only significant predictor of variance in word learning ability.

CONCLUSIONS & IMPLICATIONS

Children with phonological impairment can be lexically precocious and learn new words like their peers without phonological impairment. Contrary to expectations, vocabulary knowledge rather than expressive phonological ability explained variance in measures of word learning. These findings question an assumption that children with phonological impairment have underspecified phonological representations. They also highlight the heterogeneity among children with phonological impairment and the need to better understand the nature of their difficulty learning the phonological system of the ambient language.

WHAT THIS PAPER ADDS

What is already known on the subject There is limited research examining the word learning abilities of children with phonological impairment. Most previous research focuses on word properties such as phonotactic probability and neighbourhood density. Within the existing literature there are different reports and conclusions regarding the word learning abilities of children with phonological impairment and whether their word learning differs from that of children with typically developing speech. What this study adds to existing knowledge This study found that vocabulary was the strongest predictor of word learning across children with and without phonological impairment. There was no significant difference in word learning ability between children with and without phonological impairment. However, children with lexically precocious vocabulary abilities were significantly better at word learning than children with average vocabulary abilities. What are the potential or actual clinical implications of this work? Findings from this study support the importance of assessing and considering measures of word learning-including vocabulary-when working with children with phonological impairment. This study indicates that it is possible to use stories coupled with measures of confrontation naming and story retell to gain deeper insight into children's word learning abilities.

The role of intrinsic reward in adolescent word learning

Relatively little work has focused on why we are motivated to learn words. In adults, recent experiments have shown that intrinsic reward signals accompany successful word learning from context. In addition, the experience of reward facilitated long-term memory for words. In adolescence, developmental changes are seen in reward and motivation systems as well as in reading and language systems. Here, in the face of this developmental change, we ask whether adolescents experience reward from word learning, and how the reward and memory benefit seen in adults is modulated by age. We used a naturalistic reading paradigm, which involved extracting novel word meanings from sentence context without the need for explicit feedback. By exploring ratings of enjoyment during the learning phase, as well as recognition memory for words a day later, we assessed whether adolescents show the same reward and learning patterns as adults. We tested 345 children between the ages of 10-18 (N > 84 in each 2-year age-band) using this paradigm. We found evidence for our first prediction: children aged 10-18 report greater enjoyment for successful word learning. However, we did not find evidence for age-related change in this developmental period, or memory benefits. This work gives us greater insight into the process of language acquisition and sets the stage for further investigations of intrinsic reward in typical and atypical development. RESEARCH HIGHLIGHTS: We constantly learn words from context, even in the absence of explicit rewards or feedback. In adults, intrinsic reward experienced during word learning is linked to a dopaminergic circuit in the brain, which also fuels enhancements in memory for words. We find adolescents also report enhanced reward or enjoyment when they successfully learn words from sentence context. The relationship between reward and learning is maintained between the ages of 10 and 18. Unlike in adults, we did not observe ensuing memory benefits.

The development of lexical processing: Real-time phonological competition and semantic activation in school age children

Prior research suggests that the development of speech perception and word recognition stabilises in early childhood. However, recent work suggests that development of these processes continues throughout adolescence. This study aimed to investigate whether these developmental changes are based solely within the lexical system or are due to domain general changes, and to extend this investigation to lexical-semantic processing. We used two Visual World Paradigm tasks: one to examine phonological and semantic processing, one to capture non-linguistic domain-general skills. We tested 43 seven- to nine-year-olds, 42 ten- to thirteen-year-olds, and 30 sixteen- to seventeen-year-olds. Older children were quicker to fixate the target word and exhibited earlier onset and offset of fixations to both semantic and phonological competitors. Visual/cognitive skills explained significant, but not all, variance in the development of these effects. Developmental changes in semantic activation were largely attributable to changes in upstream phonological processing. These results suggest that the concurrent development of linguistic processes and broader visual/cognitive skills lead to developmental changes in real-time phonological competition, while semantic activation is more stable across these ages.

A maturational frequency discrimination deficit may explain developmental language disorder

Auditory perceptual deficits are widely observed among children with developmental language disorder (DLD). Yet, the nature of these deficits and the extent to which they explain speech and language problems remain controversial. In this study, we hypothesize that disruption to the maturation of the basilar membrane may impede the optimization of the auditory pathway from brainstem to cortex, curtailing high-resolution frequency sensitivity and the efficient spectral decomposition and encoding of natural speech. A series of computational simulations involving deep convolutional neural networks that were trained to encode, recognize, and retrieve naturalistic speech are presented to demonstrate the strength of this account. These neural networks were built on top of biologically truthful inner ear models developed to model human cochlea function, which-in the key innovation of the present study-were scheduled to mature at different rates over time. Delaying cochlea maturation qualitatively replicated the linguistic behavior and neurophysiology of individuals with language learning difficulties in a number of ways, resulting in (a) delayed language acquisition profiles, (b) lower spoken word recognition accuracy, (c) word finding and retrieval difficulties, (d) "fuzzy" and intersecting speech encodings and signatures of immature neural optimization, and (e) emergent working memory and attentional deficits. These simulations illustrate many negative cascading effects that a primary maturational frequency discrimination deficit may have on early language development and generate precise and testable hypotheses for future research into the nature and cost of auditory processing deficits in children with language learning difficulties. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Object labeling and disambiguation in 4-month-old infants

The account that word learning starts in earnest during the second year of life, when infants have mastered the disambiguation skills, has recently been challenged by evidence that infants during the first year already know many common words. The preliminary ability to rapidly map and disambiguate linguistic labels was tested in Italian-speaking infants (N = 96, 47 boys; age = 4 and 6 months, eye tracking). Infants can rapidly map linguistic labels to objects and movements, and disambiguate the intended referents to novel words, but they fail with sinewave analogs. In hearing infants, mapping and disambiguation emerge early in development, and are flexible as to which visual referents infants are willing to map to linguistic labels, but may be constrained to linguistic sounds.

The Role of Feedback in the Statistical Learning of Language-Like Regularities

In language learning, learners engage with their environment, incorporating cues from different sources. However, in lab-based experiments, using artificial languages, many of the cues and features that are part of real-world language learning are stripped away. In three experiments, we investigated the role of positive, negative, and mixed feedback on the gradual learning of language-like statistical regularities within an active guessing game paradigm. In Experiment 1, participants received deterministic feedback (100%), whereas probabilistic feedback (i.e., 75% or 50%) was introduced in Experiment 2. Finally, Experiment 3 explored the impact of mixed probabilistic feedback (33% positive, 33% negative, 33% no feedback). The results showed that cross-situational learning of words was observed without feedback, but participants were able to learn structural regularities of the miniature language only when feedback was provided. Interestingly, the presence of positive feedback was particularly helpful for the learner, promoting more in-depth learning of the artificial language.

Grounded language acquisition through the eyes and ears of a single child

Starting around 6 to 9 months of age, children begin acquiring their first words, linking spoken words to their visual counterparts. How much of this knowledge is learnable from sensory input with relatively generic learning mechanisms, and how much requires stronger inductive biases? Using longitudinal head-mounted camera recordings from one child aged 6 to 25 months, we trained a relatively generic neural network on 61 hours of correlated visual-linguistic data streams, learning feature-based representations and cross-modal associations. Our model acquires many word-referent mappings present in the child's everyday experience, enables zero-shot generalization to new visual referents, and aligns its visual and linguistic conceptual systems. These results show how critical aspects of grounded word meaning are learnable through joint representation and associative learning from one child's input.

The phonological congruency modulated long-term form priming of Chinese characters

Elucidating the interaction between lexical processing and word learning is essential for a complete understanding of the underlying mechanisms of each of them. Long-term priming for words reflects an interplay between lexical processing and word learning. Although robust long-term priming effects have been found between two occurrences of the same word and between semantically similar words, it remains unclear whether long-term priming between orthographically similar words (i.e., long-term form priming) is a reliable effect. Following the theoretical analysis based on the connectionist framework, we articulated the possibility that long-term form priming might be modulated by the phonological congruency between the prime and target words, and that if this modulator was under control, reliable effects of long-term form priming would emerge. However, this hypothesis has not been adequately tested empirically. The present study tested this hypothesis by using Chinese phonograms and the phonetic radicals embedded in them as the prime and target items. In three experiments that varied in the types of stimuli and testing tasks, we consistently found that when the prime and target had the same phonology, naming the prime facilitated later processing of the target, while when they had different phonologies, the priming effect was inhibitory. These observations were consistent with the connectionist account of long-term priming for words. Our findings help confirm the reliability, generalizability, and robustness of long-term form priming and elucidate its underlying mechanisms, and suggesting promising future directions on the interactions between lexical processing and word learning.

Novel word learning ability in 24-month-olds: The interactive role of mother's work status and education level

Using both online and offline measures, this study investigates how maternal education and work status (stay-at-home, part-time, full-time) are jointly associated with infants' word learning ability and vocabulary size. One hundred 24-month-old infants completed a lab-based mutual exclusivity task, which assesses infants' novel word learning ability. Caregivers reported infants' productive vocabulary size using the MCDIs. There was no evidence for an association between infants' productive vocabulary size and maternal education, maternal work status, or their interaction. However, infants' novel word learning ability was significantly related to both maternal factors and their interaction. The positive association between maternal education and word learning performance was attenuated for infants of part-time and full-time working mothers compared to infants with at home mothers. These findings suggest that using real-time measures with high task demand may better capture developmental differences in infants and expand our understanding of maternal factors contributing to early language development.

A network model of referent identification by toddlers in a visual world task

We present a neural network model of referent identification in a visual world task. Inputs are visual representations of item pairs unfolding with sequences of phonemes identifying the target item. The model is trained to output the semantic representation of the target and to suppress the distractor. The training set uses a 200-word lexicon typically known by toddlers. The phonological, visual, and semantic representations are derived from real corpora. Successful performance requires correct association between labels and visual and semantic representations, as well as correct location identification. The model reproduces experimental evidence that phonological, perceptual, and categorical relationships modulate item preferences. The model provides an account of how language can drive visual attention in the inter-modal preferential looking task.

Parents' talk about conceptual categories with infants: stability, variability, and implications for expressive language development

Children's exposure to talk about conceptual categories plays a powerful role in shaping their conceptual development. However, it remains unclear when parents begin to talk about categories with young children and whether such talk relates to children's language skills. This study examines relations between parents' talk about conceptual categories and infants' expressive language development. Forty-seven parent-infant dyads were videotaped playing together at child age 10, 12, 14, and 16 months. Transcripts of interactions were analyzed to identify parents' talk about conceptual categories. Children's expressive language development was assessed at 18 months. Findings indicate that parents indeed talked about conceptual categories with infants and that talk was stable across time, with college-educated parents producing more than non-college-educated parents. Further, parents' talk about conceptual categories between 10 and 16 months predicted children's 18-month expressive language. This study sheds new light on mechanisms through which early experiences may support children's language development.

The Development of Speaking and Singing in Infants May Play a Role in Genomics and Dementia in Humans

The development of the central auditory system, including the auditory cortex and other areas involved in processing sound, is shaped by genetic and environmental factors, enabling infants to learn how to speak. Before explaining hearing in humans, a short overview of auditory dysfunction is provided. Environmental factors such as exposure to sound and language can impact the development and function of the auditory system sound processing, including discerning in speech perception, singing, and language processing. Infants can hear before birth, and sound exposure sculpts their developing auditory system structure and functions. Exposing infants to singing and speaking can support their auditory and language development. In aging humans, the hippocampus and auditory nuclear centers are affected by neurodegenerative diseases such as Alzheimer's, resulting in memory and auditory processing difficulties. As the disease progresses, overt auditory nuclear center damage occurs, leading to problems in processing auditory information. In conclusion, combined memory and auditory processing difficulties significantly impact people's ability to communicate and engage with their societal essence.

How do Autistic and Neurotypical Children's Interests Influence their Accuracy During Novel Word Learning?

Word learning depends on attention - children must focus on the right things at the right times. However, autistic children often display restricted interests, limiting their intake of stimuli during word learning. This study investigates how category interests influence word learning in autism and neurotypical development. Autistic and neurotypical children matched on receptive vocabulary used a touch-screen computer to learn novel words associated with animals (high-interest stimuli) and objects (neutral-interest stimuli) via fast mapping. Response accuracy and speed were examined at referent selection, 5-minute retention, and 24-hour retention. Both groups identified meanings of novel words associated with unfamiliar animals and objects via mutual exclusivity with comparable accuracy. After 5 minutes, autistic children retained animal names with greater accuracy than neurotypical children. Autistic children showed a greater increase in their accuracy between 5-minute and 24-hour retention and outperformed neurotypical children across conditions after a night's sleep. Across groups, 24-hour retention was predicted by number of target word repetitions heard at referent selection, indicating a relationship between fast mapping input and retention. However, autistic children were slower to respond correctly, particularly in the animal condition. For autistic children, superior word learning associated with high-interest stimuli was relatively short-term, as sleep appeared to consolidate their memory representations for neutral-interest stimuli. Although these results demonstrate that fundamental word learning mechanisms are not atypical in autism, slower response times may signal a speed-accuracy trade-off that could have implications for naturalistic language acquisition. Our findings also indicate favourable environmental conditions to scaffold word learning.

What have we learned from 15 years of research on cross-situational word learning? A focused review

In 2007 and 2008, Yu and Smith published their seminal studies on cross-situational word learning (CSWL) in adults and infants, showing that word-object-mappings can be acquired from distributed statistics despite in-the-moment uncertainty. Since then, the CSWL paradigm has been used extensively to better understand (statistical) word learning in different language learners and under different learning conditions. The goal of this review is to provide an entry-level overview of findings and themes that have emerged in 15 years of research on CSWL across three topic areas (mechanisms of CSWL, CSWL across different learner and task characteristics) and to highlight the questions that remain to be answered.

Language in educational apps for pre-schoolers. A comparison of grammatical constructions and psycholinguistic features in apps, books and child directed speech

Language in touchscreen apps could be useful as an additional source of children's language input, alongside child directed speech (CDS) and books. Here we performed the first analysis of language in apps, as compared with books and CDS. We analysed language in 18 of the most popular educational apps targeting pre-schoolers and compared their language content to children's books and CDS with respect to types of constructions and psycholinguistic features of words. We found that apps contained lower frequency words and had lower lexical diversity compared to CDS, and shorter utterances compared to books. Apps may thus provide an enriched supplementary form of input for young children, due to containing less frequent words. However, apps do not expose children to a high proportion of questions and complex sentences, both of which are crucial for supporting child's development of structurally rich constructions.

Executive function skills account for a bilingual advantage in English novel word learning among low-income preschoolers

The current study compared economically disadvantaged bilingual and monolingual preschoolers' performance on an English novel word learning task and examined whether children's executive function (EF) skills account for differences in novel word learning performance across groups. In total, 39 English monolinguals and 35 Spanish-English bilingual preschoolers from low-income homes completed a battery of EF measures and the Quick Interactive Language Screener to gauge English novel word learning ability. Within a poverty context, bilingual preschoolers performed significantly better on measures of English novel word learning as compared with their monolingual peers. This bilingual advantage in novel word learning ability was mediated by short-term memory, but not inhibition or attention shifting, which indicates that gains in short-term memory may facilitate word learning in English for bilingual preschoolers from economically disadvantaged backgrounds. These findings have important practical implications for interventions designed to promote English vocabulary growth for low-income bilingual children.

The growing gap: A study of sleep, encoding, and consolidation of new words in chronic traumatic brain injury

Word learning is an iterative and dynamic process supported by multiple neural and cognitive systems. Converging evidence from behavioral, cellular, and systems neuroscience highlights sleep as an important support for memory and word learning over time. In many lab-based word learning experiments, participants encode and subsequently retrieve newly learned words in a single session. These designs are inadequate to capture the full dynamic word learning process, making them less ecologically valid. Single timepoint studies also limit investigation of the role of behavioral and lifestyle factors, like sleep, in supporting word learning over time. Adults with a history of traumatic brain injury (TBI), who commonly exhibit deficits in the memory systems that support word learning and report concomitant sleep disturbance, provide a unique opportunity to examine the link between memory, sleep, and word learning. Here we examined word learning over time and the influence of sleep on short- and long-term word recall in 50 adults with chronic moderate-severe TBI and 50 demographically matched neurotypical peers. We used a randomized within-participant crossover design to assess immediate encoding of new words and the consolidation of those words over time across intervals that did or did not involve sleep. Participants completed this study over the course of two weeks in their own homes to capture the iterative, dynamic process of real-world word learning. We also measured sleep in free living conditions using actigraphy throughout the experiment. Participants with TBI exhibited a word learning deficit that began at encoding and persisted across time. Critically, this deficit grew over the course of the week. The performance gap between groups was larger at the 1-week post-test than the immediate post-test, suggesting deficits in both encoding and consolidation of new words in individuals with TBI. Participants with and without TBI remembered more words when they slept after learning. Ecologically valid research designs that examine the relationship between memory, sleep, and word learning over time promise to advance mechanistic accounts of word learning and improve the long-term retention of new words in individuals with and without brain injury.

What do children's errors tell us about the strategies used during a word inferencing task?

A vital and often overlooked aspect of word learning is the ability to establish deep semantic knowledge by adjusting and fine-tuning new word meanings as information becomes available. Here we studied differences in children's ability to update incorrect or incomplete word meanings by studying error types in a word inferencing task. The participants, 45 8- and 9-year-olds, read three sentences that all ended with the same nonsense word and were asked to identify the meaning of the last word. Importantly, the third sentence always provided the most useful information about the word's meaning. When children made errors, two types of responses were of interest. The first was when children gave a response that ignored the third sentence but fit one or two of the earlier ones. This suggests that the children had failed to update the meaning accurately. The second was when children were given enough information in the three sentences yet said that they were still unable to identify a word meaning. This suggests that the children would not attempt to infer a word when they were unsure of the answer. When controlling for number of correct responses, we found that children with smaller vocabularies were significantly more likely to fail to incorporate the third sentence, whereas children with large vocabularies were more likely to say that they were still unable to identify a meaning. These findings indicate that children with smaller vocabularies may be at risk of incorrectly inferring a new word's meaning rather than seeking further information to ensure accuracy.

Resolving the associative learning paradox by category learning in pigeons

A wealth of evidence indicates that humans can engage two types of mechanisms to solve category-learning tasks: declarative mechanisms, which involve forming and testing verbalizable decision rules, and associative mechanisms, which involve gradually linking stimuli to appropriate behavioral responses.1,2,3 In contrast to declarative mechanisms, associative mechanisms have received surprisingly little attention in the broader category-learning literature. Although various forms of associatively driven artificial intelligence (AI) have matched-and even surpassed-humans' performance on several challenging problems,3,4,5,6 associative learning is routinely dismissed as being too simple to power the impressive cognitive achievements of both humans and non-human species.6,7,8,9 Here, we attempt to resolve this paradox by demonstrating that pigeons-which appear to rely solely on associative learning mechanisms in several tasks that promote declarative rule use by humans3,10,11,12-succeed at learning a novel, highly demanding category structure that ought to hinder declarative rule use: the sectioned-rings task. Our findings highlight the power and flexibility that associative mechanisms afford in the realm of category learning.

Examining the Relation Between Exercise and Word Learning in Preschool-Age Children

PURPOSE

There is evidence suggesting that aerobic exercise immediately after vocabulary training can improve word recall in school-age children. This work examined whether the previously identified word-learning benefits associated with exercise can be extended to preschoolers. Additionally, we evaluated whether the effects of physical activity on vocabulary learning may be influenced by existing language skills that the child possesses.

METHOD

Children ages 3-6 years completed the study (N = 42). Data were collected via a virtual testing session in which participants completed a word-learning task that included two experimental conditions (exercise and resting). In the resting measure, children were taught names of novel objects and then sat down and colored for 3 min before being tested on their ability to identify the trained words. The exercise condition was identical, except that participants engaged in 3 min of guided aerobic exercise before testing. Additionally, at the end of the visit, participants completed the Quick Interactive Language Screener (QUILS), which measured general language skills.

RESULTS

Accuracy of word recognition was significantly higher after the exercise condition compared to the resting condition. Furthermore, this pattern of results was not related to children's existing language skills, as measured by the QUILS.

CONCLUSIONS

This study is one of the first to closely examine the relation between physical activity and word-learning abilities in children as young as 3-6 years of age. Results align with previous findings stating that aerobic exercise can boost vocabulary learning and suggest that this is the case regardless of existing language skills.

The timescales of word learning in children with language delays: In-the-moment mapping, retention, and generalization

Learning new words and, subsequently, a lexicon, is a time-extended process requiring encoding of word-referent pairs, retention of that information, and generalization to other exemplars of the category. Some children, however, fail in one or more of these processes resulting in language delays. The present study examines the abilities of children who vary in vocabulary size (including both children with normal language (NL) and late talking (LT) children) across multiple timescales/processes - known and novel word mapping, novel word retention, and novel noun generalization. Results indicate that children with lower language skills suffer from deficits in quick in-the-moment mapping of known words compared to their NL peers, but age and vocabulary size rather than normative vocabulary ranking or NL/LT status better predicts performance on retention and generalization processes. Implications for understanding language development as a holistic process with multiple interacting variables are discussed.

Pragmatics aid referent disambiguation and word learning in young children and adults

How do children succeed in learning a word? Research has shown robustly that, in ambiguous labeling situations, young children assume novel labels to refer to unfamiliar rather than familiar objects. However, ongoing debates center on the underlying mechanism: Is this behavior based on lexical constraints, guided by pragmatic reasoning, or simply driven by children's attraction to novelty? Additionally, recent research has questioned whether children's disambiguation leads to long-term learning or rather indicates an attentional shift in the moment of the conversation. Thus, we conducted a pre-registered online study with 2- and 3-year-olds and adults. Participants were presented with unknown objects as potential referents for a novel word. Across conditions, we manipulated whether the only difference between both objects was their relative novelty to the participant or whether, in addition, participants were provided with pragmatic information that indicated which object the speaker referred to. We tested participants' immediate referent selection and their retention after 5 min. Results revealed that when given common ground information both age groups inferred the correct referent with high success and enhanced behavioral certainty. Without this information, object novelty alone did not guide their selection. After 5 min, adults remembered their previous selections above chance in both conditions, while children only showed reliable learning in the pragmatic condition. The pattern of results indicates how pragmatics may aid referent disambiguation and learning in both adults and young children. From early ontogeny on, children's social-cognitive understanding may guide their communicative interactions and support their language acquisition. RESEARCH HIGHLIGHTS: We tested how 2-3-year-olds and adults resolve referential ambiguity without any lexical cues. In the pragmatic context both age groups disambiguated novel word-object-mappings, while object novelty alone did not guide their referent selection. In the pragmatic context, children also showed increased certainty in disambiguation and retained new word-object-mappings over time. These findings contribute to the ongoing debate on whether children learn words on the basis of domain-specific constraints, lower-level associative mechanisms, or pragmatic inferences.

The development of lexical inhibition in spoken word recognition

As a spoken word unfolds over time, similar sounding words (cap and cat) compete until one word "wins". Lexical competition becomes more efficient from infancy through adolescence. We examined one potential mechanism underlying this development: lexical inhibition, by which activated candidates suppress competitors. In Experiment 1, younger (7-8 years) and older (12-13 years) children heard words (cap) in which the onset was manipulated to briefly boost competition from a cohort competitor (cat). This was compared to a condition with a nonword (cack) onset that would not inhibit the target. Words were presented in a visual world task during which eye movements were recorded. Both groups showed less looking to the target when perceiving the competitor-splice relative to the nonword-splice, showing engagement of lexical inhibition. Exploratory analyses of linguistic adaptation across the experiment revealed that older children demonstrated consistent lexical inhibition across the experiment and younger children did not, initially showing no effect in the first half of trials and then a robust effect in the latter half. In Experiment 2, adults also displayed consistent lexical inhibition in the same task. These findings suggest that younger children do not consistently engage lexical inhibition in typical listening but can quickly bring it online in response to certain linguistic experiences. Computational modeling showed that age-related differences are best explained by increased engagement of inhibition rather than growth in activation. These findings suggest that continued development of lexical inhibition in later childhood may underlie increases in efficiency of spoken word recognition. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

No need to forget, just keep the balance: Hebbian neural networks for statistical learning

Language processing in humans has long been proposed to rely on sophisticated learning abilities including statistical learning. Endress and Johnson (E&J, 2021) recently presented a neural network model for statistical learning based on Hebbian learning principles. This model accounts for word segmentation tasks, one primary paradigm in statistical learning. In this discussion paper we review this model and compare it with the Hebbian model previously presented by Tovar and Westermann (T&W, 2017a; 2017b; 2018) that has accounted for serial reaction time tasks, cross-situational learning, and categorization paradigms, all relevant in the study of statistical learning. We discuss the similarities and differences between both models, and their key findings. From our analysis, we question the concept of "forgetting" in the model of E&J and their suggestion of considering forgetting as the critical ingredient for successful statistical learning. We instead suggest that a set of simple but well-balanced mechanisms including spreading activation, activation persistence, and synaptic weight decay, all based on biologically grounded principles, allow modeling statistical learning in Hebbian neural networks, as demonstrated in the T&W model which successfully covers learning of nonadjacent dependencies and accounts for differences between typical and atypical populations, both aspects that have not been fully demonstrated in the E&J model. We outline the main computational and theoretical differences between the E&J and T&W approaches, present new simulation results, and discuss implications for the development of a computational cognitive theory of statistical learning.

Understanding preschoolers' word learning success in different scenarios: disambiguation meets statistical learning and eBook reading

Children's ability to learn new words during their preschool years is crucial for further academic success. Previous research suggests that children rely on different learning mechanisms to acquire new words depending on the available context and linguistic information. To date, there is limited research integrating different paradigms to provide a cohesive view of the mechanisms and processes involved in preschool children's word learning. We presented 4 year-old children (n = 47) with one of three different novel word-learning scenarios to test their ability to connect novel words to their correspondent referents without explicit instruction to do so. The scenarios were tested with three exposure conditions of different nature: (i) mutual exclusivity-target novel word-referent pair presented with a familiar referent, prompting fast-mapping via disambiguation, (ii) cross-situational-target novel word-referent pair presented next to an unfamiliar referent prompting statistically tracking the target pairs across trials, and (iii) eBook - target word-referent pairs presented within an audio-visual electronic storybook (eBook), prompting inferring meaning incidentally. Results show children succeed at learning the new words above chance in all three scenarios, with higher performance in eBook and mutual exclusivity than in cross-situational word learning. This illustrates children's astounding ability to learn while coping with uncertainty and varying degrees of ambiguity, which are common in real-world situations. Findings extend our understanding of how preschoolers learn new words more or less successfully depending on specific word learning scenarios, which should be taken into account when working on vocabulary development for school readiness in the preschool years.

Margarita glasses and high heels: How attention to shape, age, and vocabulary impacts children's recognition of typical and atypical exemplars

Children's ability to recognize object shape is foundational for successful early word learning. However, the prototypical shape of objects may not be easily accessible-take margarita glasses, for instance. The current study examined 304 U.S. children 17- to 42-month-old (152 females) from 2017 to 2020, asking how shape, age, and vocabulary abilities predict recognition of everyday objects. Children's ability to recognize objects increases with age and vocabulary, replicating prior work. Moreover, performance was partially moderated by object's typicality and shape features, and children's own attention to shape (shape bias) may mediate the effect, especially with prototypically shaped objects. The current study highlights how both child-specific variables and context features interact to shape language abilities, underscoring the emergent and multi-causal nature of word learning.

Direct Instruction Improves Word Learning for Children With Developmental Language Disorder

PURPOSE

The current study compared the effects of direct instruction versus indirect exposure on multiple aspects of novel word learning for children with developmental language disorder (DLD) and children with typical language development (TLD).

METHOD

Participants included 36 children with DLD and 45 children with TLD. All children were in the first grade and 6-8 years of age (Mdn = 7 years; 2 months). Using a between-subjects design, children were randomly assigned to be exposed to novel words and their unfamiliar referents via either direct instruction (each referent presented in isolation with an explicit goal of learning) or indirect exposure (multiple referents presented with the goal of answering yes/no questions).

RESULTS

In alternative forced-choice measures of recognition, children with DLD were less accurate than their TLD peers in linking words to referents, encoding semantic categories for words, and encoding detailed representations of word forms. These differences in word learning were accounted for by a constellation of cognitive measures, including receptive vocabulary, phonological memory, visuospatial memory, and sustained attention. All children were similarly accurate in retaining word forms over a 24- to 48-hr delay. Children with TLD were more accurate in all aspects of word learning following direct instruction compared to indirect exposure. Benefits from direct instruction were observed for children with DLD in link and semantic, but not word form, learning.

CONCLUSIONS

These results suggest that vocabulary interventions with direct instruction can help children with DLD learn some, but not all, aspects of novel words. Additional support is necessary to help children with DLD encode rich phonological representations.

Convergence and divergence in prediction from vocabulary and speed of word processing

Toddler vocabulary knowledge and speed of word processing are associated with downstream language and cognition. Here, we investigate whether these associations differ across measures. At age two, 101 participants (55 monolingual French-speaking and 46 monolingual English-speaking children) completed a two-alternative forced choice task, yielding measures of decontextualized vocabulary (number of correct responses) and haptic speed of word processing (latency of correct responses). At ages three, four, and five children completed a battery of language assessments and an executive function task. Growth curve models revealed that age-two vocabulary significantly predicted age-three performance (but not growth from age three to four or four to five) across all language assessments but speed of processing did not predict language outcomes in final models. Finally, speed of processing was correlated with executive function at age three whereas vocabulary was not. Results suggest that vocabulary is associated with a range of downstream language abilities whereas haptic speed of processing may be associated with executive control.

Use of Mutual Exclusivity and its Relationship to Language Ability in Toddlers with Autism Spectrum Disorder

To efficiently learn new words, children use constraints such as mutual exclusivity (ME) to narrow the search for potential referents. The current study investigated the use of ME in toddlers with autism spectrum disorder (ASD) and neurotypical (NT) peers matched on nonverbal cognition. Thirty-two toddlers with ASD and 26 NT toddlers participated in a looking-while-listening task. Images of novel and familiar objects were presented along with a novel or familiar label. Overall, toddlers with ASD showed less efficient looking toward a novel referent when a novel label was presented compared to NT toddlers, controlling for age and familiar word knowledge. However, toddlers with ASD and higher language ability demonstrated more robust use of ME than those with lower language ability.

Investigating the Mechanisms Driving Referent Selection and Retention in Toddlers at Typical and Elevated Likelihood for Autism Spectrum Disorder

It was suggested that children's referent selection may not lay memory traces sufficiently strong to lead to retention of new word-object mappings. If this was the case we expect incorrect selections to be easily rectified through feedback. Previous work suggested this to be the case in toddlers at typical likelihood (TL) but not in those at elevated likelihood (EL) for autism spectrum disorder (ASD) (Bedford et al., ). Yet group differences in lexical knowledge may have confounded these findings. Here, TL (N = 29) and EL toddlers (N = 75) chose one of two unfamiliar objects as a referent for a new word. Both groups retained the word-referent mapping above chance when their choices were immediately reinforced but were at chance after corrective feedback. The same pattern of results was obtained when children observed another experimenter make the initial referent choice. Thus, children's referent choices lay memory traces that compete with subsequent correction; these strong word-object associations are not a result of children actively choosing potential referents for new words.

Multiple Mechanisms of Word Learning in Late-Talking Children: A Longitudinal Study

PURPOSE

The aim of this study was to identify variability in word-learning mechanisms used by late-talking children using a longitudinal study design, which may explain variability in late-talking children's outcomes.

METHOD

A cohort of typically developing children (n = 40) and children who were classified as late-talking children at age 2;0 (years;months; ≤ 10th percentile on expressive vocabulary, n = 21) were followed up at ages 3;0 and 3;6. We tested the cohort across tasks designed to isolate different mechanisms involved in word learning: encoding and producing spoken forms of words (using a nonword repetition task), identifying referents for words (using a fast mapping task), and learning associations between words and referents (using a cross-situational word-learning task).

RESULTS

Late-talking children had lower accuracy on nonword repetition than typically developing children, despite most of the sample reaching typical ranges for expressive vocabulary at age 3;6. There were no between-groups differences in fast mapping and retention accuracy; however, both were predicted by concurrent expressive vocabulary. Late-talking children performed less accurately than typically developing children on cross-situational word-learning retention trials, despite showing no between-groups differences during training trials. Combining performance across all three tasks predicted approximately 45% of the variance in vocabulary outcomes at the last time point.

CONCLUSIONS

Late-talking children continue to have deficits in phonological representation that impact their word-learning ability and expressive language abilities but do not show difficulties in fast mapping novel words. Late-talking children may also struggle to retain associative information about word-referent mappings. Late-talking children thus use some, but not all, word-learning mechanisms differently than typically developing children.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20405856.

The Slow Development of Real-Time Processing: Spoken-Word Recognition as a Crucible for New Thinking About Language Acquisition and Language Disorders

Words are fundamental to language, linking sound, articulation, and spelling to meaning and syntax; and lexical deficits are core to communicative disorders. Work in language acquisition commonly focuses on how lexical knowledge-knowledge of words' sound patterns and meanings-is acquired. But lexical knowledge is insufficient to account for skilled language use. Sophisticated real-time processes must decode the sound pattern of words and interpret them appropriately. We review work that bridges this gap by using sensitive real-time measures (eye tracking in the visual world paradigm) of school-age children's processing of highly familiar words. This work reveals that the development of word recognition skills can be characterized by changes in the rate at which decisions unfold in the lexical system (the activation rate). Moreover, contrary to the standard view that these real-time skills largely develop during infancy and toddlerhood, they develop slowly, at least through adolescence. In contrast, language disorders can be linked to differences in the ultimate degree to which competing interpretations are suppressed (competition resolution), and these differences can be mechanistically linked to deficits in inhibition. These findings have implications for real-world problems such as reading difficulties and second-language acquisition. They suggest that developing accurate, flexible, and efficient processing is just as important a developmental goal as is acquiring language knowledge.

The map trap: Why and how word learning research should move beyond mapping

A pervasive goal in the study of how children learn word meanings is to explain how young children solve the mapping problem. The mapping problem asks how language learners connect a label to its referent. Mapping is one part of word learning, however, it does not reflect other critical components of word meaning construction, such as the encoding of lexico-semantic relations and socio-pragmatic context. In this paper, we argue that word learning researchers' overemphasis of mapping has constrained our experimental paradigms and hypotheses, leading to misconceived theories and policy interventions. We first explain how the mapping focus limits our ability to study the richness and complexity of what infants and children learn about, and do with, word meanings. Then, we describe how our focus on mapping has constrained theory development. Specifically, we show how it has led to (a) the misguided emphasis on referent selection and ostensive labeling, and (b) the undervaluing of diverse pathways to word knowledge, both within and across cultures. We also review the consequences of the mapping focus outside of the lab, including myopic language learning interventions. Last, we outline an alternative, more inclusive approach to experimental study and theory construction in word learning research. This article is categorized under: Psychology > Language Psychology > Theory and Methods Psychology > Learning.

DIANA, a Process-Oriented Model of Human Auditory Word Recognition

This article presents DIANA, a new, process-oriented model of human auditory word recognition, which takes as its input the acoustic signal and can produce as its output word identifications and lexicality decisions, as well as reaction times. This makes it possible to compare its output with human listeners’ behavior in psycholinguistic experiments. DIANA differs from existing models in that it takes more available neuro-physiological evidence on speech processing into account. For instance, DIANA accounts for the effect of ambiguity in the acoustic signal on reaction times following the Hick–Hyman law and it interprets the acoustic signal in the form of spectro-temporal receptive fields, which are attested in the human superior temporal gyrus, instead of in the form of abstract phonological units. The model consists of three components: activation, decision and execution. The activation and decision components are described in detail, both at the conceptual level (in the running text) and at the computational level (in the Appendices). While the activation component is independent of the listener’s task, the functioning of the decision component depends on this task. The article also describes how DIANA could be improved in the future in order to even better resemble the behavior of human listeners.

Cross-Situational Word Learning With Multimodal Neural Networks

In order to learn the mappings from words to referents, children must integrate co-occurrence information across individually ambiguous pairs of scenes and utterances, a challenge known as cross-situational word learning. In machine learning, recent multimodal neural networks have been shown to learn meaningful visual-linguistic mappings from cross-situational data, as needed to solve problems such as image captioning and visual question answering. These networks are potentially appealing as cognitive models because they can learn from raw visual and linguistic stimuli, something previous cognitive models have not addressed. In this paper, we examine whether recent machine learning approaches can help explain various behavioral phenomena from the psychological literature on cross-situational word learning. We consider two variants of a multimodal neural network architecture and look at seven different phenomena associated with cross-situational word learning and word learning more generally. Our results show that these networks can learn word-referent mappings from a single epoch of training, mimicking the amount of training commonly found in cross-situational word learning experiments. Additionally, these networks capture some, but not all of the phenomena we studied, with all of the failures related to reasoning via mutual exclusivity. These results provide insight into the kinds of phenomena that arise naturally from relatively generic neural network learning algorithms, and which word learning phenomena require additional inductive biases.

Learning Words in Two Languages: Manipulating Exemplar Variability for Within- and Cross-Language Generalization

PURPOSE

This article aims to describe how exemplar variability can manipulate the word learning environment to maximize within- and cross-language generalization in Spanish-English bilinguals. Furthermore, we examined sources of individual variability that predicted word learning.

METHOD

Nineteen Spanish-English bilingual children participated in a word learning task presenting words in both languages. Children learned words either in a high variability condition (in which multiple exemplars are introduced with the target word) or in a no variability condition (in which the same referent is used with the target word). Word learning was tracked over the course of the training, and retention was examined once the training was discontinued. Children's generalization of referents within and across languages was also examined.

RESULTS

The exemplar variability effect was observed in within-language generalization trials, whereas cross-language generalization was less robust. Nevertheless, cross-language associations emerged in examining the role of language proficiency, such that semantic skills in English predicted word retention across languages. Similarly, children's propensity to code-switch during language production was positively correlated with retention of words learned in the high variability condition.

CONCLUSIONS

The findings show that Spanish-English bilingual children may make use of exemplar variability to support word learning in different ways compared with monolinguals. The exemplar variability effect interacts with children's acquired language skills and word learning abilities at the start of the intervention. This study provides preliminary evidence from which future research can develop word learning interventions that are responsive to the needs of multilinguals.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19241856.

Exploring the Linguistic, Cognitive, and Social Skills Underlying Lexical Processing Efficiency as Measured by the Looking-while-Listening Paradigm

The looking-while-listening (LWL) paradigm is frequently used to measure toddlers' lexical processing efficiency (LPE). Children's LPE is associated with vocabulary size, yet other linguistic, cognitive, or social skills contributing to LPE are not well understood. It also remains unclear whether LPE measures from two types of LWL trials (target-initial versus distractor-initial trials) are differentially associated with the abovementioned potential correlates of LPE. We tested 18- to 24-month-olds and found that children's word learning on a fast-mapping task was associated with LPE measures from all trials and distractor-initial trials but not target-initial trials. Children's vocabulary and pragmatic skills were both associated with their fast-mapping performance. Executive functions and pragmatic skills were associated with LPE measures from distractor-initial but not target-initial trials. Hence, LPE as measured by the LWL paradigm may reflect a constellation of skills important to language development. Methodological implications for future studies using the LWL paradigm are discussed.

Mutual Exclusivity in Pragmatic Agents

One of the great challenges in word learning is that words are typically uttered in a context with many potential referents. Children's tendency to associate novel words with novel referents, which is taken to reflect a mutual exclusivity (ME) bias, forms a useful disambiguation mechanism. We study semantic learning in pragmatic agents-combining the Rational Speech Act model with gradient-based learning-and explore the conditions under which such agents show an ME bias. This approach provides a framework for investigating a pragmatic account of the ME bias in humans but also for building artificial agents that display an ME bias. A series of analyses demonstrates striking parallels between our model and human word learning regarding several aspects relevant to the ME bias phenomenon: online inference, long-term learning, and developmental effects. By testing different implementations, we find that two components, pragmatic online inference and incremental collection of evidence for one-to-one correspondences between words and referents, play an important role in modeling the developmental trajectory of the ME bias. Finally, we outline an extension of our model to a deep neural network architecture that can process more naturalistic visual and linguistic input. Until now, in contrast to children, deep neural networks have needed indirect access to (supposed to be novel) test inputs during training to display an ME bias. Our model is the first one to do so without using this manipulation.

Visual perceptual salience and novel referent selection in children with and without autism spectrum disorder

BACKGROUND & AIMS

Many young children with autism spectrum disorder (ASD) demonstrate striking delays in early vocabulary development. Experimental studies that teach the meanings of novel nonwords can determine the effects of linguistic and attentional factors. One factor that may affect novel referent selection in children with ASD is visual perceptual salience-how interesting (i.e., striking) stimuli are on the basis of their visual properties. The goal of the current study was to determine how the perceptual salience of objects affected novel referent selection in children with ASD and children who are typically developing (TD) of similar ages (mean age 3-4 years).

METHODS

Using a screen-based experimental paradigm, children were taught the names of four unfamiliar objects: two high-salience objects and two low-salience objects. Their comprehension of the novel words was assessed in low-difficulty and high-difficulty trials. Gaze location was determined from video by trained research assistants.

RESULTS

Contrary to initial predictions, findings indicated that high perceptual salience disrupted novel referent selection in the children with ASD but facilitated attention to the target object in age-matched TD peers. The children with ASD showed no significant evidence of successful novel referent selection in the high-difficulty trials. Exploratory reaction time analyses suggested that the children with autism showed "stickier" attention-had more difficulty disengaging (i.e., looking away)-from high-salience distracter images than low-salience distracter images, even though the two images were balanced in salience for any given test trial.

CONCLUSIONS AND CLINICAL IMPLICATIONS

These findings add to growing evidence that high perceptual salience has the potential to disrupt novel referent selection in children with ASD. These results underscore the complexity of novel referent selection and highlight the importance of taking the immediate testing context into account. In particular, it is important to acknowledge that screen-based assessments and screen-based learning activities used with children with ASD are not immune to the effects of lower level visual features, such as perceptual salience.

Logical word learning: The case of kinship

We examine the conceptual development of kinship through the lens of program induction. We present a computational model for the acquisition of kinship term concepts, resulting in the first computational model of kinship learning that is closely tied to developmental phenomena. We demonstrate that our model can learn several kinship systems of varying complexity using cross-linguistic data from English, Pukapuka, Turkish, and Yanomamö. More importantly, the behavioral patterns observed in children learning kinship terms, under-extension and over-generalization, fall out naturally from our learning model. We then conducted interviews to simulate realistic learning environments and demonstrate that the characteristic-to-defining shift is a consequence of our learning model in naturalistic contexts containing abstract and concrete features. We use model simulations to understand the influence of logical simplicity and children’s learning environment on the order of acquisition of kinship terms, providing novel predictions for the learning trajectories of these words. We conclude with a discussion of how this model framework generalizes beyond kinship terms, as well as a discussion of its limitations.

THE DEVELOPMENT OF COMMUNICATION ACROSS TIMESCALES

How do young children learn to organize the statistics of communicative input across milliseconds and months? Developmental science has made progress in understanding how infants learn patterns in language and how infant-directed speech is engineered to ease short-timescale processing, but less is known about how they link perceptual experiences across multiple levels of processing within an interaction (from syllables to stories) and across development. In this article, we propose that three domains of research - statistical summary, neural processing hierarchies, and neural coupling - will be fruitful in uncovering the dynamic exchange of information between children and adults, both in the moment and in aggregate. In particular, we discuss how the study of brain-to-brain and brain-to-behavior coupling between children and adults will further our understanding of how children's neural representations become aligned with the increasingly complex statistics of communication across timescales.

Prior Exposure and Toddlers' Sleep-Related Memory for Novel Words

Children can easily link a novel word to a novel, unnamed object—something referred to as fast mapping. Despite the ease and speed with which children do this, their memories for novel fast-mapped words can be poor unless they receive memory supports such as further exposure to the words or sleep. Axelsson, Swinton, Winiger, and Horst (2018) found that 2.5-year-old children who napped after fast mapping had better retention of novel words than children who did not nap. Retention declined for those who did not nap. The children received no memory supports and determined the word-object mappings independently. Previous studies report enhanced memories after sleeping in children and adults, but the napping children’s retention in the Axelsson et al. study remained steady across time. We report a follow-up investigation where memory supports are provided after fast mapping to test whether memories would be enhanced following napping. Children’s retention of novel words improved and remained greater than chance; however, there was no nap effect with no significant difference between the children who napped and those who did not. These findings suggest that when memory supports are provided, retention improves, and the word–object mappings remain stable over time. When memory traces are weak and labile, such as after fast mapping, without further memory supports, sleeping soon after helps stabilise and prevent decay of word–object mappings.

Learning Through Processing: Toward an Integrated Approach to Early Word Learning

Children's linguistic knowledge and the learning mechanisms by which they acquire it grow substantially in infancy and toddlerhood, yet theories of word learning largely fail to incorporate these shifts. Moreover, researchers' often-siloed focus on either familiar word recognition or novel word learning limits the critical consideration of how these two relate. As a step toward a mechanistic theory of language acquisition, we present a framework of "learning through processing" and relate it to the prevailing methods used to assess children's early knowledge of words. Incorporating recent empirical work, we posit a specific, testable timeline of qualitative changes in the learning process in this interval. We conclude with several challenges and avenues for building a comprehensive theory of early word learning: better characterization of the input, reconciling results across approaches, and treating lexical knowledge in the nascent grammar with sufficient sophistication to ensure generalizability across languages and development.

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.