The boundary effect, namely the infants' failures to compare small and large numerosities, is well documented in studies using visual stimuli. The prevailing explanation is that the numerical system used to process sets up to 3 is incompatible with the system employed for numbers >3. This study investigates the boundary effect in 10-month-old…

For the current study, a multi-measure, micro-analytic approach was used to prospectively explore the role of preliminary symbolic play with single and multi-objects in language milestone development and vice versa. Fourteen infants followed up in monthly one hour sessions between the ages of 8 and 16 months. Their spontaneous play acts and vocal…

Before they even talk, infants become sensitive to the speech sounds of their native language and recognize the auditory form of an increasing number of words. Traditionally, these early perceptual changes are attributed to an emerging knowledge of linguistic categories such as phonemes or words. However, there is growing skepticism surrounding…

There is a long-standing debate in the literature about the benefits that acoustic components of Infant Directed Speech (IDS) might have for infants' language acquisition. One of the highly contested features is vowel space expansion, which refers to the enlargement of the acoustic space between the corner vowels /i, u, a/ in IDS compared to Adult…

Purpose: The purpose of the present study was to examine whether there is a listening preference for child-directed speech (CDS) over backward speech in moderate-preterm infants (MPIs). Method: Eighteen MPIs of gestational age of 32.0 weeks (range: 32-34.06 weeks), chronological age of 8.09 months, and maturation age of 6.48 months served as the…

Research on "parentese," the acoustically exaggerated, slower, and higher-pitched speech directed toward infants, has mostly focused on maternal contributions, although it has long been known that fathers also produce parentese. Given recent societal changes in family dynamics, it is necessary to revise these mother-centered models of…

Children's speech is influenced by the speech they hear, in particular by the parental speech addressed directly to them. The aim of this study was to analyse toddlers' speech with their parents and to investigate the influence of specific characteristics of child-directed speech on child speech in real time during mother-child and father-child…

It is known that infant-directed speech (IDS) plays a key role in language development. Previous research, however, has also identified significant variability across societies in terms of how often IDS occurs. For example, some studies report very little IDS in non-western, small-scale societies -- including children growing up in small-scale…

Iconic words imitate their meanings. Previous work has demonstrated that iconic words are more common in infants' early speech, and in adults' child-directed speech (e.g., Perry et al., 2015; 2018). This is consistent with the proposal that iconicity provides a benefit to word learning. Here we explored iconicity in four diverse language…

For the past 25 years, researchers have investigated language input to children from high- and low-socioeconomic status (SES) families. Hart and Risley first reported a "30 Million Word Gap" between high-SES and low-SES children. More recent studies have challenged the size or even existence of this gap. The present study is a…

This longitudinal pilot study examined the pointing behavior of two Israeli Deaf mothers and one hearing mother over the course of their infant's signed/spoken language acquisition. Three aspects were analyzed: (a) frequency of use; (b) function; and (c) pointing form. The findings indicated that the Deaf mothers used pointing more frequently than…

Turn-taking in dialogue is an essential part of communication and early language experience. The prevalence of utterances and the timing of responses in dialogue were examined at 14 and 36 months of age in 104 mother-child dyads from the Early Head Start Research and Evaluation Project (EHSREP). Mothers varied in their level of depression risk…

In the first year of life, infants' speech perception becomes attuned to the sounds of their native language. This process of early phonetic learning has traditionally been framed as phonetic category acquisition. However, recent studies have hypothesized that the attunement may instead reflect a perceptual space learning process that does not…

Purpose: This retrospective study aimed to amass large data sets to enable statistical comparisons of communication outcomes for infants receiving cochlear implants (CIs) before 9 months of age compared to groups who received their first CI between 9 months and 3.5 years of age. Method: Speech perception scores and experienced clinicians'…

This present research analyses the linguistic environmental setting in homes of children under the age of two years from different social groups and looks at the extent to which the speech from other children contributes to shaping that environment. The corpus includes recordings of spontaneous speech from middle-class households in residential…