Exploring Input Parameters in an Expressive Vocabulary Treatment With Late Talkers

Abstract

Purpose The aims of this study were (a) to assess the efficacy of the Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment and (b) to compare treatment outcomes for expressive vocabulary acquisition in late talkers in 2 conditions: 3 target words/90 doses per word per session versus 6 target words/45 doses per word per session. Method We ran the treatment protocol for 16 sessions with 24 primarily monolingual English-speaking late talkers. We calculated a d score for each child, compared treatment to control effect sizes, and assessed the number of words per week children acquired outside treatment. We compared treatment effect sizes of children in the condition of 3 target words/90 doses per word to those in the condition of 6 target words/45 doses per word. We used Bayesian repeated-measures analysis of variance and Bayesian t tests to answer our condition-level questions. Results With an average treatment effect size of almost 1.0, VAULT was effective relative to the no-treatment condition. There were no differences between the different dose conditions. Discussion The VAULT protocol was an efficacious treatment that has the potential to increase the spoken vocabulary of late-talking toddlers and provides clinicians some flexibility in terms of number of words targeted and dose number, keeping in mind the interconnectedness of treatment parameters. Supplemental Material https://doi.org/10.23641/asha.11593323

Teaching shape bias to increase the expressive vocabularies of late talkers

“…These studies used different intervention approaches than the present study and each other, and their treatments were longer and/or more intensive than the present research. The participants in three of these studies [6,7,18] showed two to three times greater increases in their expressive vocabularies than those in the present study. LTs in the other two studies increased their expressive vocabularies by as many or fewer words than those in the present research [21,26].…”

“…Alt and colleagues published two statistical learning-based studies designed to increase the expressive vocabularies of LTs [6,7]. Although neither addressed shape bias specifically, they are included here to demonstrate the potential for this category of intervention.…”

“…By the end of the treatment, the participants had demonstrated improvements in the number of target words produced, and their expressive vocabulary raw and percentile scores on the MB-CDI [2]. Alt et al [6] replicated these findings, as well as demonstrated significant vocabulary growth in experimental vs. delayed-treatment control group at the end of treatment and 4-6 weeks later.…”

“…There are a number of directions that additional investigations of this nature could take. The effects of dosage, for example, could be examined by providing varying time and density of the intervention [6]. Additional statistical learningbased aspects of lexical development, such as fast mapping and neighborhood density, could be added to the protocol, especially because they are also problematic for LTs [42,49] (see [50] for counter evidence).…”

“…Successful interventions for LTs have primarily focused on increasing vocabulary exposure, providing contextual supports, and directly teaching target vo-cabulary items [5]. Recent work by Alt and colleagues [6,7] suggest that interventions targeting cognitive skills that underlie word learning can also be effective. The present study builds on this work by exploring the feasibility of an intervention for LTs that focuses on the statistical learning-based lexical principle of shape bias.…”