Repetition Versus Variability in Verb Learning: Sometimes Less Is More

Purpose This study examined whether 2-year-olds are better able to acquire novel verb meanings when they appear in varying linguistic contexts, including both content nouns and pronouns, as compared to when the contexts are consistent, including only content nouns. Additionally, differences between typically developing toddlers and late talkers were explored. Method Forty-seven English-acquiring 2-year-olds ( n = 14 late talkers, n = 33 typically developing) saw scenes of actors manipulating objects. These actions were labeled with novel verbs. In the varied condition, children heard sentences containing both content nouns and pronouns (e.g., “The girl is ziffing the truck. She is ziffing it!”). In the consistent condition, children heard the verb an equal number of times, but only with content nouns (e.g., “The girl is ziffing the truck. The girl is ziffing the truck!”). At test, children were shown two new scenes and were asked to find the novel verb's referent. Children's eye gaze was analyzed as a measure of learning. Results Mixed-effects regression analyses revealed that children looked more toward the correct scene in the consistent condition than the varied condition. This difference was more pronounced for late talkers than for typically developing children. Conclusion To acquire an initial representation of a new verb's meaning, children, particularly late talkers, benefit more from hearing the verb in consistent linguistic contexts than in varying contexts.

The Effects of a Parent-Implemented Language Intervention on Late-Talkers’ Expressive Skills: The Mediational Role of Parental Speech Contingency and Dialogic Reading Abilities

Several qualitative and quantitative features of parental speech input support children’s language development and may play a critical role in improving such process in late talkers. Parent-implemented interventions targeting late-talkers have been developed to promote children’s language outcomes by enhancing their linguistic environment, i.e., parental speech input. This study investigated the effect of a parent-implemented intervention in increasing late talkers’ expressive skills through modifications in structural and functional features of parental speech input. Forty-six thirty-one-month-old late talkers differing in their birth condition (either low-risk preterm or full-term) participated in the study with a parent; 24 parent-child dyads received a parent-implemented intervention centered on dialogic reading and focused stimulation techniques, whereas the other 22 dyads constituted the control group. At pre- and post-intervention, dyads took part in a parent-child shared book-reading session and both parental and child’s speech measures were collected and examined. Results showed that the intervention positively affected parents’ use of responses and expansions of children’s verbal initiatives, as well as the parental amount of talking over reading, whereas no structural features of parental input resulted modified. Mediation analyses pointed out that the intervention indirectly enhanced late-talkers’ use of verbal types and tokens through changes in parental use of expansions and amount of talking over reading. As birth status was entered as a covariate in the analysis, these findings can be extended to children with different gestational age. We conclude that the parent-implemented intervention was effective in supporting late-talkers’ gains in language development as a cascade result of the improvements in parental contingency and dialogic reading abilities. These promising findings suggest to examine not only children and parental outcomes but also the intervention mechanisms promoting changes in late-talkers’ language development as a clearer view on such process can inform the development of feasible, ecological and effective programs.

Parent-Implemented Hanen Program It Takes Two to Talk®: An Exploratory Study in Spain

Parent-implemented interventions are a highly common approach for enhancing communication and linguistic abilities of late talkers, involving a population that shows a small expressive vocabulary in the absence of other deficits that could explain it. This study aimed to compare the outcomes of a parent-implemented language intervention, It Takes Two to Talk®—The Hanen Program® for Parents (ITTT), to a clinician-directed therapy. Participants were 17 families and their late-talking children: 10 families took part in ITTT and 7 in the clinician-directed modality. The outcomes in the social communication domain were more favorable for the ITTT group, but there were no significant differences between groups as regards vocabulary and syntax. In terms of parents, the research focused on examining if there were significant changes in parents’ stress and their perceptions of their children’s communication abilities. No differences were observed in the level of stress. In contrast, the group that received the ITTT program significantly altered their perceptions of their children’s communication difficulties in comparison with the clinician-directed therapy. These results have implications in the clinical management of late-talking children, and they are discussed in terms of evidence-based practice.

Late Language Emergence

Infants usually say their first word at the age of 12 months; subsequently, within the next 6–12 months, they develop a vocabulary of approximately 50 words, along with the ability to make two-word combinations. However, late talkers (LTs) demonstrate delayed speech in the absence of hearing impairments, cognitive developmental issues or relevant birth history. The prevalence of late language emergence (LLE) in toddlers is reported to be 10–15%. Studies of LTs are both theoretically and clinically significant. Early diagnosis and clinical intervention may result in relatively stable speech capabilities by the early school years. The present article aimed to review both theoretical and empirical studies regarding LLE within the process of first language acquisition, as well as methods for the early diagnosis of delayed speech in children and the authors’ own clinical and theoretical recommendations. Keywords: Infants; Speech; Language Development; Speech-Language Pathology; Language Development Disorders; Rehabilitation of Speech and Language Disorders.

Vocabulary Acquisition and Usage for Late Talkers Treatment: Effect on Expressive Vocabulary and Phonology

Purpose This study examined the effect of Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment on toddlers' expressive vocabulary and phonology. Parent acceptability of VAULT treatment was also considered. Method We used a nonconcurrent multiple baseline single case experimental design with three late talking toddlers aged 21–25 months. The treatment was delivered twice weekly in 30-min sessions for 8 weeks by a rotating team of four speech-language pathologists. Toddlers heard three of their 10 strategically selected target words a minimum of 64 times in play activities each session. Expressive vocabulary and phonology was assessed pre–post, with parent interviews conducted posttreatment. Results All toddlers increased production of target words and expressive vocabulary. Ambient expressive vocabulary size increased by an average of 16 words per week (range of 73–169 words learned over the treatment period). On a 20-item, single-word speech assessment, the toddlers' phonetic inventories increased on average from three to seven consonants, and five to eight vowels. Two toddlers used protowords pretreatment, which were replaced by recognizable attempts at words posttreatment. Parents reported the treatment was acceptable for the child and their family with future consideration of parent-based delivery of the treatment in the home. Conclusions The results of this treatment provide further evidence of a model of intervention informed by the principles of implicit learning, and the interconnectedness of phonological and lexical learning. Investigation is required to establish the efficacy and feasibility of VAULT in clinical contexts. Supplemental Material https://doi.org/10.23641/asha.14714733

A Vocabulary Acquisition and Usage for Late Talkers Treatment Efficacy Study: The Effect of Input Utterance Length and Identification of Responder Profiles

Purpose This study examined the efficacy of the Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment in a version that manipulated the length of clinician utterance in which a target word was presented (dose length). The study also explored ways to characterize treatment responders versus nonresponders. Method Nineteen primarily English-speaking late-talking toddlers (aged 24–34 months at treatment onset) received VAULT and were quasirandomly assigned to have target words presented in grammatical utterances matching one of two lengths: brief (four words or fewer) or extended (five words or more). Children were measured on their pre- and posttreatment production of (a) target and control words specific to treatment and (b) words not specific to treatment. Classification and Regression Tree (CART) analysis was used to classify responders versus nonresponders. Results VAULT was successful as a whole (i.e., treatment effect sizes of greater than 0), with no difference between the brief and extended conditions. Despite the overall significant treatment effect, the treatment was not successful for all participants. CART results (using participants from the current study and a previous iteration of VAULT) provided a dual-node decision tree for classifying treatment responders versus nonresponders. Conclusions The input-based VAULT treatment protocol is efficacious and offers some flexibility in terms of utterance length. When VAULT works, it works well. The CART decision tree uses pretreatment vocabulary levels and performance in the first two treatment sessions to provide clinicians with promising guidelines for who is likely to be a nonresponder and thus might need a modified treatment plan. Supplemental Material https://doi.org/10.23641/asha.14226641