With Some Help From Others' Hands: Iconic Gesture Helps Semantic Learning in Children With Specific Language Impairment

Object Shape and Depth of Word Representations in Preschoolers

This study examined the effect of a shape cue (i.e., co-speech gesture) on word depth. We taught 23 preschoolers (M = 3;5 years, SD = 5.82) novel objects with either shape (SHP) or indicator (IND) gestures. SHP gestures mimicked object form, but IND gestures were not semantically related to the object (e.g., an upward-facing palm, extended toward the object). Each object had a unique IND or SHP gesture. Outcome measures reflected richer semantic and phonological learning in the SHP than in the IND condition. In the SHP condition, preschoolers (a) expressed more semantic knowledge, (b) said more sounds in names, and (c) generalized more names to untaught objects. There were also fewer disruptions to prime picture names in the SHP condition; we discuss the benefit of a co-speech shape gesture to capitalize on well-established statistical word learning patterns.

Using Theory to Drive Intervention Efficacy: The Role of Dose Form in Interventions for Children with DLD

‘Dose form’ is a construct that has evolved over the last number of years and is central to treating childhood language disorders. In this commentary, we present a framework of dose form that includes techniques, procedures, manner of instruction, and intervention context. We present key findings from a systematic review exploring the impact of intervention dose form on oral language outcomes (specifically morphosyntax and vocabulary learning) in children with DLD. We then discuss the hypothesized theoretical mechanisms of action underpinning these findings.

The Impact of Intervention Dose Form on Oral Language Outcomes for Children With Developmental Language Disorder

Purpose The aim of this study was to extract key learning from intervention studies in which qualitative aspects of dosage, dose form, have been examined for children with developmental language disorder (DLD)-in vocabulary, morphosyntax, and phonology domains. This research paper emerged from a pair of systematic reviews, aiming to synthesize available evidence regarding qualitative and quantitative aspects of dosage. While quantitative aspects had been experimentally manipulated, the available evidence for dose form (tasks or activities within which teaching episodes are delivered) was less definitive. Despite this, the review uncovered insights of value to DLD research. Method A preregistered systematic review (PROSPERO ID: CRD42017076663) adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was completed. Included papers were quasi-experimental, randomized controlled trial, or cohort analytic studies, published in any language between January 2006 and May 2019; oral language interventions with vocabulary, morphosyntax, or phonology outcomes; and participants with DLD (M = 3-18 years). The intention was to include papers in which dose form was experimentally manipulated or statistically analyzed, while quantitative dosage aspects were controlled, such that definitive conclusions about optimal dose form could be drawn and gaps in the evidence identified. Results Two hundred and twenty-four papers met the above inclusion criteria; 27 focused on dose form. No study controlled for all quantitative aspects of dosage such that we could effectively address our original research questions. Despite this, key points of learning emerged with implications for future research. Conclusions There is tentative evidence of advantages for explicit over implicit instruction and of the benefits of variability in input, elicited production, and gestural and other visual supports. With careful design of dose form, there is potential to design more efficient interventions. Speech-language pathology research would benefit from an agreed taxonomy of dose form components and standardized reporting of intervention studies, to enable cross-study comparisons and a systematic accrual of knowledge to identify optimal dose form for clinical application.

Progressive Reduction of Iconic Gestures Contributes to School-Aged Children's Increased Word Production

The economic principle of communication, according to which successful communication can be reached by least effort, has been studied for verbal communication. With respect to nonverbal behavior, it implies that forms of iconic gestures change over the course of communication and become reduced in the sense of less pronounced. These changes and their effects on learning are currently unexplored in relevant literature. Addressing this research gap, we conducted a word learning study to test the effects of changing gestures on children's slow mapping. We applied a within-subject design and tested 51 children, aged 6.7 years (SD = 0.4), who learned unknown words from a story. The storyteller acted on the basis of two conditions: In one condition, in which half of the target words were presented, the story presentation was enhanced with progressively reduced iconic gestures (PRG); in the other condition, half of the target words were accompanied by fully executed iconic gestures (FEG). To ensure a reliable gesture presentation, children were exposed to a recorded person telling a story in both conditions. We tested the slow mapping effects on children's productive and receptive word knowledge three minutes as well as two to three days after being presented the story. The results suggest that children's production of the target words, but not their understanding thereof, was enhanced by PRG.

Making Object Shape Explicit for Toddlers With Late Language Emergence

Purpose Toddlers with late language emergence have difficulty acquiring an object vocabulary that is well defined by shape early in development. Without object words, subsequent language growth is delayed. The current study tested an intervention scaffold that highlights object shape during word teaching so that toddlers with late language emergence may establish themselves in the early stages of object word learning. Method Four toddlers with late language emergence participated in a brief dose of two interventions that differed only in semantic scaffold-a co-speech shape gesture or a co-speech indicator gesture. Co-speech refers to the word model and gesture occurring simultaneously. Shape gestures explicitly conveyed object form, whereas indicator gestures directed attention to the object. A single-subject experimental design tracked naming of taught objects and untaught exemplars. The study compared the mean number of phonemes produced in names between conditions. Results The four participants (a) extended more names to novel exemplars, (b) named more exemplar types, and (c) named more exemplar tokens when learned with shape gestures than with indicating gestures. The shape gesture advantage was confirmed with "percentage of nonoverlapping data" analysis. Not only did the shape gesture increase naming over the indicator gesture but more sounds were also mapped on average in the shape condition. Conclusion The current study used a semantic approach to the word learning problem in toddlers with late language emergence. We conclude that co-speech shape gestures led to semantic enrichment and facilitated phonological binding of the word representation. Future experiments should focus on a component analysis in parent-implemented interventions for greater carryover in the child's natural environment (i.e., external validity).

The evaluation of word-learning abilities in people with developmental language disorder: a scoping review

BACKGROUND

The ability to learn new words is critical in the development of oral and written language, and significantly impacts engagement in social, academic and vocational situations. Many studies have evaluated the word-learning process in people with developmental language disorder (DLD). However, methodologies for assessment are heterogeneous, creating difficulties in synthesizing findings and identifying gaps in the knowledge base.

AIMS

To scope systematically the literature and identify key methodological parameters considered in evaluations of word learning in people with DLD; and to identify gaps in the literature to guide further research in this area.

METHODS & PROCEDURES

Twelve databases were searched and a total of 70 studies that met eligibility criteria were identified. The studies were evaluated according to key parameters that researchers varied in their word-learning methodologies.

MAIN CONTRIBUTION

Most research has focused on word learning in the oral modality, and specifically in children with DLD. Fewer studies have explored word learning in adults and adolescents with DLD, and in the written modality. Depending on the research question and theoretical perspective driving the investigation, methodologies for assessing word learning considered a range of parameters, including words being learned, learning context and cues to support learning in the tasks.

CONCLUSIONS & IMPLICATIONS

This review aggregates a variety of methods used previously to assess word learning. Findings highlight the need for further research to explore areas such as: the learning of varied word types (e.g., adjectives and adverbs); learning in the written modality; and word learning (both oral and written) in adolescents and adults with DLD.