Working Memory Predicts New Word Learning Over and Above Existing Vocabulary and Nonverbal IQ

Influence of Child-Level Factors and Lexical Characteristics on Vocabulary Knowledge of Children With Cochlear Implants and Hearing Aids

Recent studies indicate children who are deaf and hard of hearing who use cochlear implants or hearing aids know fewer spoken words than their peers with typical hearing, and often those vocabularies differ in composition. To date, however, the interaction of a child's auditory profile with the lexical characteristics of words he or she knows has been minimally explored. The purpose of the present study is to evaluate how audiological history, phonological memory, and overall vocabulary knowledge interact with growth in types of spoken words known by children who are deaf and hard of hearing compared to children with typical hearing. Children with cochlear implants (n = 36) and hearing aids (n = 39) were compared to children with typical hearing (n = 47) at ages 4 and 6. Children participated in measures of phonological memory and vocabulary knowledge, inclusive of an experimental measure with words of varying phonotactic probability and neighborhood density. Results indicate that children with hearing aids and with cochlear implants tend to know fewer words across all lexical conditions than children with typical hearing. For children with cochlear implants, overall vocabulary knowledge was the best predictor of a mis-matched probability and density condition, whereas it was the best predictor of matched condition for children with hearing aids. Children with cochlear implants and children with hearing aids, then, appear to have different underlying skills that interact with the lexical characteristics of words to support vocabulary growth.

Word Learning in Bilingual Children at Risk for Developmental Language Disorder

PURPOSE

The purpose of this study was to compare the novel word learning skills between Cantonese-English bilingual children at risk for developmental language disorder (DLD) and their typically developing (TD) peers.

METHOD

Participants were 24 Cantonese-English bilingual preschool children at risk for DLD and 38 TD children. Each participant was presented with eight novel words in Cantonese (first language [L1]) and eight in English (second language [L2]) over eight weekly sessions. Children's existing lexical knowledge was measured using the moving-average number of different words in language samples in L1 and L2.

RESULTS

Bilingual children at risk for DLD were scored lower than their TD peers for both languages over time. The role of lexical knowledge in children's word learning differed between the TD and DLD groups: Lexical knowledge in L1 was a predictor of L1 word learning in TD children, while lexical knowledge in L2 predicted L2 word learning in children at risk for DLD. In addition, significant cross-linguistic effects were found from L2 to L1 for both groups.

CONCLUSIONS

This study underscores the complexity of novel word learning in bilingual children at risk for DLD. Clinically, these findings suggest the value of tracking learning trajectories in bilingual children across both languages.

Neural Mechanisms of Learning and Consolidation of Morphologically Derived Words in a Novel Language: Evidence From Hebrew Speakers

We examined neural mechanisms associated with the learning of novel morphologically derived words in native Hebrew speakers within the Complementary Learning Systems (CLS) framework. Across four sessions, 28 participants were trained on an artificial language, which included two types of morphologically complex words: linear (root + suffix) with a salient structure, and non-linear (root interleaved with template), with a prominent derivational structure in participants' first language (L1). A third simple monomorphemic condition, which served as baseline, was also included. On the first and fourth sessions, training was followed by testing in an fMRI scanner. Our behavioural results showed decomposition of both types of complex words, with the linear structure more easily learned than the non-linear structure. Our fMRI results showed involvement of frontal areas, associated with decomposition, only for the non-linear condition, after just the first session. We also observed training-related increases in activation in temporal areas specifically for the non-linear condition, which was correlated with participants' L1 morphological awareness. These results demonstrate that morphological decomposition of derived words occurs in the very early stages of word learning, is influenced by L1 experience, and can facilitate word learning. However, in contrast to the CLS framework, we found no support for a shift from reliance on hippocampus to reliance on cortical areas in any of our conditions. Instead, our findings align more closely with recent theories showing a positive correlation between changes in hippocampus and cortical areas, suggesting that these representations co-exist and continue to interact with one another beyond initial learning.

Individual Predictors of Language Treatment Response in Children With Developmental Language Disorder: A Systematic Review

PURPOSE

Treatment response is the degree to which an individual benefits from a treatment. This systematic review sought to identify and synthesize research evidence regarding individual characteristics that predict language treatment response among children with developmental language disorder (DLD).

METHOD

To be eligible for inclusion, articles needed to report results of an oral language treatment program in a group of children aged 4-10 years with identified DLD and also include a quantitative analysis of the relation between one or more pretreatment child characteristics and the outcome of language treatment. Seven databases (Cumulated Index to Nursing and Allied Health Literature, Dissertations and Theses Global, Education Resources Information Center, Linguistics and Language Behavior Abstracts, PsycINFO, Medline, and Web of Science) were searched for articles in June and July 2021, with search updates conducted in May 2023. Studies were categorized by the type of treatment provided, and results were synthesized qualitatively.

RESULTS

The review included 31 studies, 1,551 participants with DLD, and over 300 statistical tests of a predictor's effect on language treatment response. Most studies (n = 21) included only monolingual speakers of English, with five studies including bilinguals and five including monolingual speakers of non-English languages. Language treatments targeted word learning in controlled or clinical conditions, grammatical learning in controlled or clinical conditions, or multiple language targets in clinical conditions. Predictors of treatment response are summarized across four categories: cognitive, demographic, pretreatment language levels, and other.

CONCLUSIONS

There were relatively few significant tests of the predictors of language treatment response. A central limitation of the evidence is that most included studies were designed to consider language treatment efficacy, not predictors of treatment response. Increasing research attention to the question of predictors of language treatment response in children with DLD is needed to enhance treatment and optimize outcomes for individual children.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26170006.

Fostering retention of word learning: The number of training sessions children retrieve words positively relates to post-training retention

During vocabulary instruction, it is important to teach words until their representations are robust enough to be retained. For adults, the number of training sessions a target item is successfully retrieved during training predicts the likelihood of post-training retention. To assess this relationship in children, we reanalyzed data from Gordon et al. (2021b, 2022). Four- to six-year-old children completed six training days with word form-object pairs and were tested one month later. Results indicate that the number of training sessions that a word form was retrieved was positively related to post-training retention. We discuss implications for vocabulary instruction and interventions.

Long-term memory consolidation of new words in children with self-limited epilepsy with centro-temporal spikes

Accelerated long-term forgetting has been studied and demonstrated in adults with epilepsy. In contrast, the question of long-term consolidation (delays > 1 day) in children with epilepsy shows conflicting results. However, childhood is a period of life in which the encoding and long-term storage of new words is essential for the development of knowledge and learning. The aim of this study was therefore to investigate long-term memory consolidation skills in children with self-limited epilepsy with centro-temporal spikes (SeLECTS), using a paradigm exploring new words encoding skills and their long-term consolidation over one-week delay. As lexical knowledge, working memory skills and executive/attentional skills has been shown to contribute to long-term memory/new word learning, we added standardized measures of oral language and executive/attentional functions to explore the involvement of these cognitive skills in new word encoding and consolidation. The results showed that children with SeLECTS needed more repetitions to encode new words, struggled to encode the phonological forms of words, and when they finally reached the level of the typically developing children, they retained what they had learned, but didn't show improved recall skills after a one-week delay, unlike the control participants. Lexical knowledge, verbal working memory skills and phonological skills contributed to encoding and/or recall abilities, and interference sensitivity appeared to be associated with the number of phonological errors during the pseudoword encoding phase. These results are consistent with the functional model linking working memory, phonology and vocabulary in a fronto-temporo-parietal network. As SeLECTS involves perisylvian dysfunction, the associations between impaired sequence storage (phonological working memory), phonological representation storage and new word learning are not surprising. This dual impairment in both encoding and long-term consolidation may result in large learning gap between children with and without epilepsy. Whether these results indicate differences in the sleep-induced benefits required for long-term consolidation or differences in the benefits of retrieval practice between the epilepsy group and healthy children remains open. As lexical development is associated with academic achievement and comprehension, the impact of such deficits in learning new words is certainly detrimental.

The Relation Between Attention and Memory

The relation between attention and memory has long been deemed important for understanding cognition, and it was heavily researched even in the first experimental psychology laboratory by Wilhelm Wundt and his colleagues. Since then, the importance of the relation between attention and memory has been explored in myriad subdisciplines of psychology, and we incorporate a wide range of these diverse fields. Here, we examine some of the practical consequences of this relation and summarize work with various methodologies relating attention to memory in the fields of working memory, long-term memory, individual differences, life-span development, typical brain function, and neuropsychological conditions. We point out strengths and unanswered questions for our own embedded processes view of information processing, which is used to organize a large body of evidence. Last, we briefly consider the relation of the evidence to a range of other theoretical views before drawing conclusions about the state of the field.

Decomposition in early stages of learning novel morphologically derived words: The impact of linear vs. non-linear structure

We examined whether morphological decomposition takes place in early stages of learning a novel language, and whether morphological structure (linear vs. non-linear) influences decomposition. Across four sessions, 41 native-Hebrew speakers learned morphologically derived words in a novel morpho-lexicon, with two complex conditions: linear and non-linear; and a third simple condition with monomorphemic words. Participants showed faster learning of trained words in the linear condition, and better generalization to untrained words for both complex conditions compared to the simple condition, with better performance for linear than non-linear morphology. Learning the root morpheme, which provides a concrete meaning, was better than learning template/suffix morphemes, which are more abstract. Overall, our results suggest that saliency of discrete units plays an important role in decomposition in early stages of learning derived words, even for speakers highly familiar with the non-linear structure in their L1.

Disentangling Processing and Storage Accounts of Working Memory Development in Childhood

Researchers have been asking the question of what drives the development of working memory (WM) during childhood for decades. This question is particularly challenging because so many aspects of cognition develop with age that it is difficult to disentangle them and find out which factors are causal or fundamental. In this review, we first prepare to discuss this issue by inquiring whether increases in storage, processing, or both are the fundamental driving factor(s) of the age-related increase in WM capability in childhood. We contend that by experimentally manipulating either factor and observing changes in the other, it is possible to learn about causal roles in WM development. We discuss research on school-aged children that seems to suggest, by means of such an approach, that the growth of storage is causal for some phases or steps in WM tasks, but that the growth of processing is causal for other steps. In our theoretical proposal, storage capacity of the focus of attention determines earlier steps of information processing by constraining the selective encoding of information into WM, whereas processing dependent on the focus of attention determines later steps, like the detection of patterns that can simplify the effective memory load and adoption of a proactive stance of maintenance in dual-task settings. Future directions for research are discussed.

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.

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.

The P300 event related potential predicts phonological working memory skills in school-aged children

The P300 event related potential (ERP) has been cited as a marker of phonological working memory (PWM); however, little is known regarding its relationship to behavioral PWM skills in early school-aged children. The current study investigates the P300 ERP recorded in response to native and non-native (English and Spanish) phoneme contrasts as a predictor of PWM skills in monolingual English-speaking first and second grade children. Thirty-three typically developing children, ages 6–9, completed a battery of phonological processing, language, and cognitive assessments. ERPs were recorded within an auditory oddball paradigm in response to both English phoneme contrasts (/ta/, /pa/) and Spanish contrasts (/t̪a/, /d̪a/). The P300 ERP recorded in response to English phoneme contrasts significantly predicted standard scores on the Nonword Repetition subtest of the Comprehensive Test of Phonological Processing, Second Edition. Spanish contrasts did not elicit a P300 response, nor were amplitude or latency values within the P300 timeframe (250–500 ms) recorded in response to Spanish contrasts related to English nonword repetition performance. This study provides further evidence that the P300 ERP in response to native phonemic contrasts indexes PWM skills, specifically nonword repetition performance, in monolingual children. Further work is necessary to determine the extent to which the P300 response to changing phonological stimuli reflects PWM skills in other populations.