Repetition Versus Variability in Verb Learning: Sometimes Less Is More

When is a word in good company for learning?

Although identifying the referents of single words is often cited as a key challenge for getting word learning off the ground, it overlooks the fact that young learners consistently encounter words in the context of other words. How does this company help or hinder word learning? Prior investigations into early word learning from children's real-world language input have yielded conflicting results, with some influential findings suggesting an advantage for words that keep a diverse company of other words, and others suggesting the opposite. Here, we sought to triangulate the source of this conflict, comparing different measures of diversity and approaches to controlling for correlated effects of word frequency across multiple languages. The results were striking: while different diversity measures on their own yielded conflicting results, once nonlinear relationships with word frequency were controlled, we found convergent evidence that contextual consistency supports early word learning. RESEARCH HIGHLIGHTS: The words children learn occur in a sea of other words. The company words keep ranges from highly variable to highly consistent and circumscribed. Prior findings conflict over whether variability versus consistency helps early word learning. Accounting for correlated effects of word frequency resolved the conflict across multiple languages. Results reveal convergent evidence that consistency helps early word learning.

Varying Syntax to Enhance Verb-Focused Intervention for 30-Month-Olds With Language Delay: A Concurrent Multiple Baseline Design

PURPOSE

The purpose of this study is to determine if 2.5-year-olds with language delay would learn verbs (spill) when presented with varying syntactic structure ("The woman is spilling the milk"/"The milk is spilling"; milk = patient or theme) in a therapeutic context. Children with language delay have proportionally small inventories of verbs, which limits expressive language development. Children who have typical language development learn verbs more robustly when presented with alternating arguments than with a single argument structure.

METHOD

Three toddlers with expressive language delay (29-30 months of age) participated in a verb-focused treatment study using a concurrent multiple baseline design. Participants were shown action videos accompanied by sentences with varied argument structure for each target verb. To assess learning pre- and posttreatment, participants were asked to demonstrate actions corresponding to each verb.

RESULTS

Visual inspection and tau analyses reveal significant posttreatment gains of target verbs taught with varying argument structures.

CONCLUSIONS

Our results indicate that learning verbs with high variability of argument roles may facilitate a strong link between lexical representations of verbs and their syntactic structures. Using argument structure variability to teach verbs as an intervention strategy has great potential and should be tested further in larger group studies.

From Recognizing Known Words to Learning New Ones: Comparing Online Speech Processing in Typically Developing and Late-Talking 2-Year-Olds

PURPOSE

This study examines online speech processing in typically developing and late-talking 2-year-old children, comparing both groups' word recognition, word prediction, and word learning.

METHOD

English-acquiring U.S. children, from the "When to Worry" study of language and social-emotional development, were identified as typical talkers (n = 67, M age = 27.0 months, SD = 1.4; Study 1) or late talkers (n = 30, M age = 27.0 months, SD = 2.0; Study 2). Children completed an eye-tracking task assessing their ability to recognize both nouns and verbs, to use verbs to predict an upcoming noun's referent, and to use verbs to infer the meaning of novel nouns.

RESULTS

Both typical and late talkers recognized nouns and verbs and used familiar verbs to predict the referents of upcoming nouns, whether the noun was familiar ("You can eat the apple") or novel ("You can eat the dax"). Late talkers were slower in using familiar nouns to orient to the target and were both slower and less accurate in using familiar verbs to identify the upcoming noun's referent. Notably, however, both groups learned and retained novel word meanings with similar success.

CONCLUSIONS

Late talkers demonstrated slower lexical processing, especially for verbs. Yet, their success in using familiar verbs to learn novel nouns suggests that, as a group, their slower processing did not impair word learning in this task. This sets the foundation for future work investigating whether these measures predict later language outcomes and can differentiate late talkers with transient delays from those with language disorders.

Can Retrieval Practice Facilitate Verb Learning in Children With Developmental Language Disorder and Their Peers With Typical Language Development?

PURPOSE

Children with developmental language disorder (DLD) have well-documented verb learning difficulties. In this study, we asked whether the inclusion of retrieval practice during the learning period would facilitate these children's verb learning relative to a similar procedure that provided no retrieval opportunities.

METHOD

Eleven children with DLD (M age = 60.09 months) and 12 children with typical language development (TD; M age = 59.92 months) learned four novel verbs in a repeated spaced retrieval (RSR) condition and four novel verbs in a repeated study (RS) condition. The words in the two conditions were heard an equal number of times, in the context of video-recorded actors performing novel actions.

RESULTS

Recall testing immediately after the learning period and 1 week later revealed greater recall for novel verbs in the RSR condition than for novel verbs in the RS condition. This was true for both groups, and for immediate as well as 1-week testing. The RSR advantage remained when children had to recall the novel verbs while watching new actors perform the novel actions. However, when tested in contexts requiring the children to inflect the novel verbs with -ing for the first time, the children with DLD were much less likely to do so than their peers with TD. Even words in the RSR condition were only inconsistently inflected.

CONCLUSIONS

Retrieval practice provides benefits to verb learning-an important finding given the challenges that verbs present to children with DLD. However, these benefits do not appear to automatically translate to the process of adding inflections to newly learned verbs but rather appear to be limited to the operations of learning the verbs' phonetic forms and mapping these forms onto associated actions.

Difference or delay? Syntax, semantics, and verb vocabulary development in typically developing and late-talking toddlers

While semantic and syntactic properties of verb meaning can impact the success of verb learning at a single age, developmental changes in how these factors influence acquisition are largely unexplored. We ask whether the impact of syntactic and semantic properties on verb vocabulary development varies with age and language ability for toddlers aged 16 to 30 months in a large sample (N = 5520, N _{Late Talkers} = 821; N _{Typically Developing} = 4699, cutoff = 15th percentile) of vocabulary checklist data from the MacArthur- Bates Communicative Development Inventory (MBCDI). Verbs from the MBCDI were coded for their syntactic and semantic properties, including manner/result meanings, durative/punctual events, and syntactic complexity. Both late talkers and typically developing children were less likely to produce syntactically complex verbs at younger ages as compared to older ages. Group differences emerged for manner/result: Typically developing children were more likely to produce manner verbs at all ages, but late talkers were more likely to produce result verbs. Regardless of group, children who produced more manner versus result verbs also had larger verb vocabulary sizes overall. These results suggest that late talkers and typically developing toddlers differ in how they build their verb vocabularies.

Semantic maturation during the comprehension-expression gap in late and typical talkers

This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity-known to influence semantic development-on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking typical talkers (TTs) and late talkers (LTs; 16-30 months old; 1257 females, 1021 gender unknown; ethnicity unknown; data downloaded in 2018) and finds that LTs, with a longer preverbal phase, produced nouns with lower contextual diversity (R²  = .80), but verbs with higher contextual diversity (R²  = .13). Study 2 compares computational network growth models of semantic maturation and finds that verbs require more semantic maturation than nouns, and TTs produce words that are more semantically mature than LTs.