Verb Vocabulary Supports Event Probability Use in Developmental Language Disorder.

PURPOSE: Children with developmental language disorder (DLD) tend to interpret noncanonical sentences like passives using event probability (EP) information regardless of structure (e.g., by interpreting "The dog was chased by the squirrel" as "The dog chased the squirrel"). Verbs are a major source of EP information in adults and children with typical development (TD), who know that "chase" implies an unequal relationship among participants. Individuals with DLD have poor verb knowledge and verb-based sentence processing. Yet, they also appear to rely more on EP information than their peers. This paradox raises two questions: (a) How do children with DLD use verb-based EP information alongside other information in online passive sentence interpretation? (b) How does verb vocabulary knowledge support EP information use? METHOD: We created novel EP biases by showing animations of agents with consistent action tendencies (e.g., clumsy vs. helpful actions). We then used eye tracking to examine how this EP information was used during online passive sentence processing. Participants were 4- to 5-year-old children with DLD (n = 20) and same-age peers with TD (n = 20). RESULTS: In Experiment 1, children with DLD quickly integrated verb-based EP information with morphosyntax close to the verb but failed to do so with distant morphosyntax. In Experiment 2, the quality of children's sentence-specific verb vocabulary knowledge was positively associated with the use of EP information in both groups. CONCLUSION: Depending on the morphosyntactic context, children with DLD and TD used EP information differently, but verb vocabulary knowledge aided its use. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25491805.

Retrieval Practice and Word Learning by Children With Developmental Language Disorder: Does Expanding Retrieval Provide Additional Benefit?

PURPOSE: The word learning of preschool-age children with developmental language disorder (DLD) is improved when spaced retrieval practice is incorporated into the learning sessions. In this preregistered study, we compared two types of spacing-an expanding retrieval practice schedule and an equally spaced schedule-to determine if one of these approaches yields better word learning outcomes for the children. METHOD: Fourteen children with DLD aged 4-5 years and 14 same-age children with typical language development (TD) learned eight novel nouns over two sessions. Spacing for half of the novel words was expanded gradually during learning; for the remaining novel words, greater spacing remained at the same level throughout learning. Immediately after the second session and 1 week later, the children's recall of the words was tested. RESULTS: The children with TD recalled more novel words than the children with DLD, although this difference could be accounted for by differences in the children's standardized receptive vocabulary test scores. The two groups were similar in their ability to retain the words over 1 week. Initially, the shorter spacing in the expanding schedule resulted in greater retrieval success than the corresponding (longer spaced) retrieval trials in the equally spaced schedule. These early shorter spaced trials also seemed to benefit retrieval of the trials with greater spacing that immediately followed. However, as the learning period progressed, the accuracy levels for the two conditions converged and were likewise similar during final testing. CONCLUSION: We need a greater understanding of how and when short spacing can be helpful to children's word learning, with the recognition that early gains might give a misleading picture of the benefits that short spacing can provide to longer term retention. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25537696.

Two pathways in vocabulary development: Large-scale differences in noun and verb semantic structure.

In adults, nouns and verbs have varied and multilevel semantic interrelationships. In children, evidence suggests that nouns and verbs also have semantic interrelationships, though the timing of the emergence of these relationships and their precise impact on later noun and verb learning are not clear. In this work, we ask whether noun and verb semantic knowledge in 16-30-month-old children tend to be semantically isolated from one another or semantically interacting from the onset of vocabulary development. Early word learning patterns were quantified using network science. We measured the semantic network structure for nouns and verbs in 3,804 16-30-month-old children at several levels of granularity using a large, open dataset of vocabulary checklist data. In a cross-sectional approach in Experiment 1, early nouns and verbs exhibited stronger network relationships with other nouns and verbs than expected across multiple network levels. Using a longitudinal approach in Experiment 2, we examined patterns of normative vocabulary development over time. Initial noun and verb learning was supported by strong semantic connections to other nouns, whereas later-learned words exhibited strong connections to verbs. Overall, these two experiments suggest that nouns and verbs demonstrate early semantic interactions and that these interactions impact later word learning. Early verb and noun learning is affected by the emergence of noun and verb semantic networks during early lexical development.

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.

The role of semantic similarity in verb learning events: Vocabulary-related changes across early development.

Verb meaning is challenging for children to learn across varied events. This study examined how the taxonomic semantic similarity of the nouns in novel verb learning events in a progressive alignment learning condition differed from the taxonomic dissimilarity of nouns in a dissimilar learning condition in supporting near (similar) and far (dissimilar) verb generalization to novel objects in an eye-tracking task. A total of 48 children in two age groups (23 girls; younger: 21-24 months, Mage = 22.1 months; older: 27-30 months: Mage = 28.3 months) who differed in taxonomic vocabulary size were tested. There were no group or learning condition differences in near generalization. The younger group demonstrated better far generalization of verbs learned with semantically dissimilar nouns. The older group demonstrated the opposite pattern, with better far generalization of verbs learned with semantically similar nouns in the progressive alignment condition. These patterns were associated with children's in-category vocabulary knowledge more than other vocabulary measures, including verb vocabulary size. Taxonomic vocabulary knowledge differentially affects verb learning and generalization across development.

Verb vocabularies are shaped by complex meanings from the onset of development.

Verbs and nouns vary in many ways - including in how they are used in language and in the timing of their early learning. We compare the distribution of semantic features that comprise early-acquired verb and noun meanings. Given overall semantic and syntactic differences between nouns and verbs, we hypothesized that the preference for directly perceptible features observed for nouns would be attenuated for verbs. Building on prior work using semantic features and semantic networks in nouns, we find that compared to early-learned nouns (N = 359), early-learned verbs (N = 103) have meanings disproportionately built from complex information inaccessible to the senses. Further, children's early verb vocabularies (N = 3,804) show semantic relationships strongly shaped by this complex information from the beginning of vocabulary development. Complexity is observed in early verb meanings and is reflected in the vocabularies of children even at the outset of verb learning.

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.

Word-learning trajectories influence long-term recall in children with developmental language disorder and typical development.

INTRODUCTION: Children with developmental language disorder (DLD) have difficulties learning words. However, the severity of these difficulties can be reduced through word learning procedures that incorporate repeated spaced retrieval (RSR). Previous studies have shown positive outcomes with RSR but we still know very little about how learning unfolds with this procedure. In this study, we focus on the process of learning under RSR. METHODS: We analyze the learning data from children with DLD and with typical development (TD) from three recent studies using RSR. We fit growth curves to the trial-by-trial learning data for immediate and spaced retrieval trials and use the characteristics of children's individual word-learning trajectories to predict their long-term recall. RESULTS: We found that children in both groups demonstrated linear growth during learning, despite breaks within and across days. Success on early immediate retrieval trials promoted success on subsequent spaced retrieval trials. Children's trial-by-trial RSR learning trajectories were related to their long-term recall: both cumulative success and growth over time on the spaced retrieval trials positively predicted long-term recall. Consecutive success was also highly correlated with growth over time. CONCLUSIONS: Repeated spaced retrieval supplemented with immediate retrieval trials during learning promotes long-term recall.

A multi-study examination of the role of repeated spaced retrieval in the word learning of children with developmental language disorder.

BACKGROUND: Many children with developmental language disorders (DLD) have well-documented weaknesses in vocabulary. In recent years, investigators have explored the nature of these weaknesses through the use of novel word learning paradigms. These studies have begun to uncover specific areas of difficulty and have provided hints about possible intervention strategies that might help these children learn words more accurately and efficiently. Among the studies of this type are those that incorporate repeated spaced retrieval activities in the learning procedures. METHODS: In this study, we examined the data from four of these studies that employed the same types of participants (4- and 5-year-old children with DLD and same-age children with typical language development), research design, and outcome measures. The studies differed primarily in the type of learning condition that was being compared to a spaced retrieval condition. A mixed-effects modeling framework was used, enabling the data from the four studies and different outcome measures to be aggregated. RESULTS: Across the studies, more words in the repeated spaced retrieval condition were recalled than those in the comparison conditions. This was true regardless of outcome measure. Children with typical language development recalled more words than the children with DLD. Both groups benefited from spaced retrieval, though effects were larger for the group with DLD. Children recalled words as accurately 1 week after learning as they did at the 5-min mark; the two groups were essentially identical in this respect. CONCLUSIONS: Overall, the findings support the continued refinement of these types of repeated spaced retrieval procedures, as they may have potential to serve as effective approaches to intervention.

Perceptual Connectivity Influences Toddlers' Attention to Known Objects and Subsequent Label Processing.

While recent research suggests that toddlers tend to learn word meanings with many "perceptual" features that are accessible to the toddler's sensory perception, it is not clear whether and how building a lexicon with perceptual connectivity supports attention to and recognition of word meanings. We explore this question in 24-30-month-olds (N = 60) in relation to other individual differences, including age, vocabulary size, and tendencies to maintain focused attention. Participants' looking to item pairs with high vs. low perceptual connectivity-defined as the number of words in a child's lexicon sharing perceptual features with the item-was measured before and after target item labeling. Results revealed pre-labeling attention to known items is biased to both high- and low-connectivity items: first to high, and second, but more robustly, to low-connectivity items. Subsequent object-label processing was also facilitated for high-connectivity items, particularly for children with temperamental tendencies to maintain focused attention. This work provides the first empirical evidence that patterns of shared perceptual features within children's known vocabularies influence both visual and lexical processing, highlighting the potential for a newfound set of developmental dependencies based on the perceptual/sensory structure of early vocabularies.

After Initial Retrieval Practice, More Retrieval Produces Better Retention Than More Study in the Word Learning of Children With Developmental Language Disorder.

Purpose Children with developmental language disorder (DLD) often have difficulty with word learning. Recent studies have shown that incorporating retrieval practice provides a significant benefit to this learning. However, we have not yet discovered the best balance between the amount of retrieval and the amount of study (hearing the word in the presence of the referent) that is provided. In this investigation, we compared a word learning procedure using more retrieval and less study with a procedure that used more study and less retrieval. Method Participants were 13 children with DLD and 13 same-age peers with typical language development (TD). Both groups ranged in age from 4 to 6 years. The children learned two sets of novel words, with each set taught in two sessions. During an initial criterion period, the children had the opportunity to retrieve all of the words. Following this period, the words were either retrieved without further study or studied without additional retrieval. Recall and recognition testing immediately followed the second learning session and was repeated 1 week later. Testing assessed the children's retention of both the word forms and their meanings. Results Better recall both immediately after learning and after 1 week was seen for the more retrieval/less study condition. This was seen for both groups of children for word form recall and for children with DLD for meaning. Group differences were not found. Conclusion This study served as a stringent test of the benefits of retrieval to children's word learning. Continued retrieval after initial retrieval practice appeared to be helpful even when further study was discontinued and when the comparison study condition had also provided retrieval practice in the initial stages. Further refinement of retrieval procedures might lead to the development of useful clinical tools to promote word learning.

The Effects of Frequency and Predictability on Repetition in Children With Developmental Language Disorder.

Purpose Studies have shown that children with typical development (TD) respond to frequency and predictability when repeating nonidiomatic multiword sequences (e.g., go wash your hands). We extended these findings by explicitly examining the interaction between frequency and predictability in a repetition task for children with developmental language disorder (DLD) and children with TD. Method We created 48 four-word phrases, manipulating two factors: the frequency of occurrence of the entire four-word phrase (e.g., look in the mirror vs. look in the basket) and the predictability of the fourth word in the phrase given the preceding three words (e.g., corn on the ___ vs. look in the ___). These phrases were presented in a repetition task to 17 children with DLD (M age = 58.89 months), 19 same-age children with TD (M age = 59.79 months), and 17 younger children with TD matched to the DLD group on nonword repetition and mean length of utterance (M age = 38.94 months). Children's repetitions were judged for the presence or absence of word and morphological errors. Only the first three words of the sequence were scored (e.g., look in the). Results We found a main effect of sequence frequency, with high-frequency sequences being repeated more accurately than low-frequency sequences, modulated by a significant interaction with predictability, where the effect of sequence frequency was larger for sequences with high-predictability contexts than for sequences with low-predictability contexts. We also found a significant effect of group, with children with DLD demonstrating poorer overall performance, particularly when compared to the same-age group with TD. Conclusions Frequency and predictability are strong predictors of language production in children with TD. These factors also have effects for children with DLD, raising important clinical questions about the design of facilitative contexts for the teaching of difficult linguistic forms.

Adjective Learning in Young Typically Developing Children and Children With Developmental Language Disorder: A Retrieval-Based Approach.

Purpose There are strong retention benefits when learners frequently test themselves during the learning period. This practice of repeated retrieval has recently been applied successfully to children's word learning. In this study, we apply a repeated retrieval procedure to the learning of novel adjectives by preschool-age children with developmental language disorder (DLD) and their typically developing (TD) peers. We ask whether the benefits of retrieval extend to children's ability to apply the novel adjectives to newly introduced objects sharing the same characteristics as the objects used during the learning period. Method Fourteen children with DLD (M age = 62.64 months) and 13 TD children (M = 62.54 months) learned novel adjectives in 2 sessions. For each child, half of the adjectives were learned in a repeated spaced retrieval condition, and half were learned in a repeated study-only condition. Recall was assessed immediately after the second learning session and 1 week later. A recognition test was also administered at the 1-week mark. Results On the recall tests, for both groups of children, recall was better for adjectives learned in the repeated spaced retrieval condition. Adjectives learned by the 2nd day were retained 1 week later. Every adjective correctly applied to an object used during the learning period was also extended accurately to new objects with the same characteristics. On these recall tests, the children with DLD did not differ from the TD group in the number of items recalled, though their phonetic accuracy was lower. On the recognition test, the DLD group showed greater accuracy for adjectives that had been learned in the repeated spaced retrieval condition than for those learned in the repeated study condition, whereas the TD group performed at high levels in both conditions. Conclusion Repeated spaced retrieval appears to provide an effective boost to word learning. Because its benefits are seen even when a word must be extended to new objects, the application of this procedure seems well suited for learning new language material rather than being limited to item-specific memorization.

Retrieval-Based Word Learning in Young Typically Developing Children and Children With Developmental Language Disorder I: The Benefits of Repeated Retrieval.

Purpose Scholars have long noted that retention improves significantly when learners frequently test themselves on the new material rather than engage in continuous study with no intermittent testing. In this study, we apply the notion of repeated testing or retrieval to the process of word learning in preschool-age children with and without developmental language disorder (DLD). Method Novel words and their meanings were taught to 10 children with DLD and 10 typically developing (TD) children matched on age (DLD, M = 63.4 months; TD, M = 63.2 months). Recall was assessed immediately after the 2nd learning session and then again 1 week later. Results Both groups showed better retention when they had attempted to retrieve the words during the learning period than when they had simply listened to and studied the words paired with their referents. Relative to their TD peers, the children with DLD seemed to be weaker in their encoding, but these children's retention over a 1-week period was indistinguishable from that of their age mates. Conclusion Word learning activities that include opportunities for repeated retrieval appear to significantly benefit retention relative to more traditional word learning activities. Supplemental Material https://doi.org/10.23641/asha.7927046.

Retrieval-Based Word Learning in Young Typically Developing Children and Children With Development Language Disorder II: A Comparison of Retrieval Schedules.

Purpose Retrieval practice has been found to be a powerful strategy to enhance long-term retention of new information; however, the utility of retrieval practice when teaching young children new words is largely unknown, and even less is known for young children with language impairments. The current study examined the effect of 2 different retrieval schedules on word learning at both the behavioral and neural levels. Method Participants included 16 typically developing children ( M TD = 61.58 months) and 16 children with developmental language disorder ( M DLD = 59.60 months). Children participated in novel word learning sessions in which the spacing of retrieval practice was manipulated: Some words were retrieved only after other words had been presented (i.e., repeated retrieval that required contextual reinstatement [RRCR]); others were taught using an immediate retrieval schedule. In Experiment 1, children's recall of the novel word labels and their meanings was tested after a 5-min delay and a 1-week delay. In Experiment 2, event-related brain potentials were obtained from a match-mismatch task utilizing the novel word stimuli. Results Experiment 1 findings revealed that children were able to label referents and to retain the novel words more successfully if the words were taught in the RRCR learning condition. Experiment 2 findings revealed that mismatching picture-word pairings elicited a robust N400 event-related brain potential only for words that were taught in the RRCR condition. In addition, children were more accurate in identifying picture-word matches and mismatches for words taught in the RRCR condition, relative to the immediate retrieval condition. Conclusions Retrieval practice that requires contextual reinstatement through spacing results in enhanced word learning and long-term retention of words. Both typically developing children and children with developmental language disorder benefit from this type of retrieval procedure. Supplemental Material https://doi.org/10.23641/asha.7927112.

Five overarching factors central to grammatical learning and treatment in children with developmental language disorder.

BACKGROUND: During grammatical treatment of children with developmental language disorder (DLD), it is natural for therapists to focus on the grammatical details of the target language that give the children special difficulty. However, along with the language-specific features of the target (e.g., for English, add -s to verbs in present tense, third-person singular contexts), there are overarching factors that operate to render the children's learning task more, or less, challenging, depending on the particular target. AIMS: To identify five such factors that can play a role in the grammatical learning of children with DLD. We use English as our example language and provide supporting evidence from a variety of other languages. MAIN CONTRIBUTION: We show that the relative degree of English-speaking children's difficulty with particular grammatical details can be affected by the extent to which these details involve: (1) bare stems; (2) opportunities for grammatical case confusion; (3) prosodic challenges; (4) grammatical and lexical aspect; and (5) deviations from canonical word order. CONCLUSIONS: During treatment, therapists will want to consider not only the English-specific features of grammatical targets but also how these more general factors can be taken into account to increase the children's success.

Third person singular -s in typical development and specific language impairment: Input and neighbourhood density.

The purpose of this study was to examine factors promoting the use of third person singular -s by 23 children with specific language impairment (SLI) and 21 children with typical development (TD). Relative proportions of third person singular -s forms in the input (input proportion) were calculated for 25 verbs based on data from an American English corpus of child-directed speech. Neighbourhood density values were also collected for these verbs. With previously collected probes of third person singular -s use for each of these verbs, we found with logistic regression that input proportion was positively associated with the likelihood of third person singular -s use for both groups. For neighbourhood density, we found that children with SLI were more likely to inflect sparse verbs than dense verbs; density was not significantly related to inflection use for TD children. We argue that as a result of their verbs' poorly encoded phonological representations, children with SLI were less able to inflect dense verbs than sparse verbs. We recommend that clinicians be aware of the effects of input proportion and neighbourhood density to ensure that assessments are representative and that treatment success is optimal.