This study explores the effects of training parents to administer focused stimulation intervention to teach specific target words to their toddlers with expressive vocabulary delays. Twenty-five mothers and their late-talking toddlers were randomly assigned to treatment and delayed-treatment (control) groups. Vocabulary targets were individually selected for each toddler based on the child's phonetic repertoire and parent report of vocabulary development. Following treatment, mothers' language input was slower, less complex, and more focused than mothers in the control group. Concomitantly, their children used more target words in naturalistic probes, used more words in free-play interaction, and were reported to have larger vocabularies overall as measured by parent report. In addition, the treatment had an effect on language development—children in the experimental group used more multiword combinations and early morphemes than children in the control group. The implications of these results are discussed with regard to the role of focused stimulation intervention for children with expressive vocabulary delays.

This study examined the relationship between variation in maternal language and variation in language development in a group of 12 children with expressive vocabulary delays. Mothers and their children participated in a parent-mediated intervention that adhered to the interactive model of language intervention. This intervention model arises out of social interactionist accounts of language acquisition and maintains that maternal language input has facilitatory effects on child development. The purpose of this study was to examine two compatible explanations for the facilitatory effects of maternal linguistic input in this intervention model: the responsivity hypothesis and the structural hypothesis. The responsivity hypothesis maintains that linguistic input that is semantically contingent on the child’s vocal or verbal utterances, or responsive to the child’s focus, facilitates language learning. The structural hypothesis posits that structural features of maternal language input that are just one step above the child’s abilities promote language learning. The results of this study indicated robust relationships between maternal use of imitation and expansion at Time 1 and measures of child language at Time 2. These results provided support for the effects of responsive language input on the language abilities of this sample of late talkers. These results have implications for social interaction theory and confirm the import of responsive input as viable intervention techniques for young children with expressive vocabulary delays.

The purpose of this investigation is to determine whether a focused stimulation intervention focusing on lexical training has indirect, secondary effects on children's phonological abilities. Twenty-five toddlers with expressive vocabulary delays and their mothers were randomly assigned to intervention and control groups. The children were between 23 and 33 months of age at entry into the study and were at the single-word stage of language development. Parents of late talkers in the experimental group were trained to employ frequent, highly concentrated presentations of target words without requiring responses. Two measures of phonological diversity (i.e., syllable structure level and consonant inventory) and one measure of accuracy of production (i.e., percent consonants correct) were measured prior to and following intervention within the context of mother-child interactions. The toddlers who received intervention made treatment gains in two areas of phonological ability. They used a greater variety of complex syllable shapes and expanded their speech sound inventories to include more consonant sounds in both initial and final position. In contrast, there were no effects of language treatment on the accuracy of correct production when compared to the adult phonological system.

f The interactive model of language intervention optimizes parent-child interaction patterns by training parents to increase their responsiveness to the child's focus and interests, and provide language models appropriate to the child's level and plan-ofthemoment. We explored the effects of a focused stimulation version of this intervention approach, in which parents used interactive intervention techniques, but targeted specific vocabulary. In this pilot study, 16 mothers and their preschool-aged children with language delays were randomly assigned to treatment and delayed-treatment (control) groups. Vocabulary targets were individually selected for each child based on the child's phonetic repertoire and parent report of vocabulary development. In accord with program objectives, children in the treatment group used more target words and acquired more symbolic play gestures than children in the control group. No significant differences were found between the two groups at posttestfor control words, or for a general measure of vocabulary development. Finally, mothers of children in the experimental group reported a I reduction in aggressive/destructive behaviors in their children after intervention.

The aim was to examine cross-cultural variation in linguistic responsiveness to young children in 10 English-speaking mother-child dyads and 10 Italian-speaking mother-child dyads. All 20 children were late talkers who possessed delays in expressive vocabulary development but age-appropriate cognitive and receptive language skills. Dyads were filmed in 15-minute free play contexts, which were transcribed and coded for measures of maternal linguistic input (e.g. rate, MLU, labels, expansions) and child language productivity (e.g. utterances, different words used). The results revealed that the Italian mothers used more utterances, spoke more quickly and used a more diverse vocabulary than the Canadian mothers. The Italian children mirrored their mothers and also used more utterances and a more diverse vocabulary than the Canadian children. Mothers in both groups used similar percentages of responsive labels and expansions. However, Italian mothers responded to fewer of their children's vocalizations, using a smaller percentage of imitations and interpretations than the Canadian mothers. Correlations between maternal input and children's language productivity revealed that contingent language measures (e.g. imitations, interpretations, expansions) were related to high levels of productivity in children in both cultural groups. The results support the use of language interventions based on increasing maternal responsiveness for these children at the one-word stage of language development. They also point to differences that may be culturally based. For example, Italian mothers use faster rates of interaction and appear to have higher expectations for their children's verbal participation in interaction. This is reflected in higher rates of language production from their children, even though children in both cultural groups have similar vocabulary sizes.