This study aimed to adapt and validate the Word Complexity Measure (WCM) for Persian-speaking toddlers. The WCM is a tool for assessing phonological complexity, originally proposed by Stoel-Gammon. The study was conducted in two phases: (1) adapting the WCM parameters to the Persian language and (2) conducting a validation study with 60…

Real-time attention coordination in parent-toddler dyads is often studied in tightly controlled laboratory settings. These studies have demonstrated the importance of joint attention in scaffolding the development of attention and the types of dyadic behaviors that support early language learning. Little is known about how often these behaviors…

This study investigated responsive and directive speech from 60 Finnish mothers to their 2-year-old children, as well as correlations with concurrent and later vocabulary. Possible gender differences with regard to both maternal speech and children's vocabulary skills were considered. There were no gender differences in maternal utterance…

Aims: Although IDS is typically described as slower than adult-directed speech (ADS), potential impacts of slower speech on language development have not been examined. We explored whether IDS speech rates in 42 mother-infant dyads at four time periods predicted children's language outcomes at two years. Method: We correlated IDS speech rate with…

Object word learning can be based on infant-related factors such as their manual actions and socio-linguistic factors such as parental input. Specific input for spatial features (i.e., size, shape, features of objects) can be related to object word comprehension in early vocabulary development. In a longitudinal study, we investigated whether fine…

Most words spoken to infants are produced in larger units, such as clauses, phrases, and sentences. As such, language learners must recognize words amidst the words that surround them. However, the phonetic forms of words change based on surrounding context. Here, we investigate the effects of a common source of phonetic change--phonological…

Learning to walk leads to an increase in language abilities; however, the underlying mechanisms accounting for this relation remain unclear. Investigating the quality of early gait control may offer some insights. The purpose of this study was to: (1) quantify how 13-month-olds (n = 39; 39% male) and 24-month-olds (n = 39; 59% male) adapt gait…

We examined the relation between maternal responsiveness and children's acquisition of mental and non-mental state vocabulary in 59 pairs of mothers and children aged 10 to 26 months as they engaged in a free-play episode. Children wore a head camera and responsiveness was defined as maternal talk that commented on the child's actions (e.g., when…

One of the most popular and widely used parent report instruments for assessing early language acquisition is the MacArthur-Bates Communicative Development Inventories (MB-CDI). This study compares normative data of the Italian Words and Sentences complete form (WS-CF) and short form (WS-SF). The samples included 752 children for the WS-CF and 816…

The relationship between first and second language in early vocabulary acquisition in bilingual children is still debated in the literature. This study compared the expressive vocabulary of 39 equivalently low-SES two-year-old bilingual children from immigrant families with different heritage languages (Romanian vs. Nigerian English) and the same…

Purpose: The study sought to determine whether the onset of canonical vocalizations in children with cochlear implants (CIs) is related to speech perception skills and spoken vocabulary size at 24 months postactivation. Method: The vocal development in 13 young CI recipients (implanted by their third birthdays; mean age at activation = 20.62…

Purpose: Children come to understand many words by the end of their 1st year of life, and yet, generally by 12 months, only a few words are said. In this study, we investigated which linguistic factors contribute to this comprehension-expression gap the most. Specifically, we asked the following: Are phonological neighborhood density, semantic…

Responsive parental communication during an infant's first year has been positively associated with later language outcomes. This study explores responsivity in mother-infant communication by modeling how change in guiding language between 7 and 11 months influences toddler vocabulary development. In a group of 32 mother-child dyads, change in…

Purpose: Pragmatics is receiving much attention in both the fields of developmental and clinical psychology; however, there is a dearth of instruments to assess pragmatic abilities specifically among young toddler-age children. The aim of the current study was to test the psychometric properties of the Italian version of the Language Use Inventory…

The goals of this study were to analyze the growth and stability of vocabulary, mean length of the three longest utterances (MLLUw), and sentence complexity in European Portuguese-speaking children aged 1;4-2;6, to explore differences in growth as a function of personal and family-related variables, and to investigate the inter-relationships among…