The Effects of Age, Dosage, and Poverty on Second Language Learning through SparkLingTM in Infant Education Centers in Madrid, Spain

The first 1000 days represent a unique window of opportunity for second language learning. In two recent studies we demonstrated that Spanish infants’ use of second-language (L2) English productive vocabulary and early utterances rapidly increased through the play-based, interactive and highly social SparkLingTM Intervention, which consists of an evidence-based method and curriculum stemming from decades of research on infant language development. Analyzing an expanded and more diverse sample of Spanish infants (n = 414; age 9–33 months) who received the SparkLingTM Intervention, this study examines the variability in L2 production, which was assessed via first-person LENA audio recordings. Infants’ age significantly and positively correlated with L2 production, demonstrating an advantage for older infants in the sample. While overall socioeconomic status (SES) was not related to L2 production, very young infants (under two years) who lived in high poverty homes showed faster increases in English production compared to peers who lived in moderate poverty homes. Infants’ attendance in the program (“dosage”) was also predictive of their L2 production outcomes. Infants across SES have the capacity to begin acquiring two languages in early education classrooms with SparkLingTM through one-hour/day sessions in social environments that engages them through frequent high-quality language input.

Relationship Between Parent Vowel Hyperarticulation in Infant-Directed Speech and Infant Phonetic Complexity on the Level of Conversational Turns

When speaking to infants, parents typically use infant-directed speech, a speech register that in several aspects differs from that directed to adults. Vowel hyperarticulation, that is, extreme articulation of vowels, is one characteristic sometimes found in infant-directed speech, and it has been suggested that there exists a relationship between how much vowel hyperarticulation parents use when speaking to their infant and infant language development. In this study, the relationship between parent vowel hyperarticulation and phonetic complexity of infant vocalizations is investigated. Previous research has shown that on the level of subject means, a positive correlational relationship exists. However, the previous findings do not provide information about the directionality of that relationship. In this study the relationship is investigated on a conversational turn level, which makes it possible to draw conclusions on whether the behavior of the infant is impacting the parent, the behavior of the parent is impacting the infant, or both. Parent vowel hyperarticulation was quantified using the vhh-index, a measure that allows vowel hyperarticulation to be estimated for individual vowel tokens. Phonetic complexity of infant vocalizations was calculated using the Word Complexity Measure for Swedish. Findings were unexpected in that a negative relationship was found between parent vowel hyperarticulation and phonetic complexity of the immediately following infant vocalization. Directionality was suggested by the fact that no such relationship was found between infant phonetic complexity and vowel hyperarticulation of the immediately following parent utterance. A potential explanation for these results is that high degrees of vowel hyperarticulation either provide, or co-occur with, large amounts of phonetic and/or linguistic information, which may occupy processing resources to an extent that affects production of the next vocalization.

What Can We Perceive In Infant Vocalization?

Infant vocalization is a well-studied area of development, however, there is a noticeable gap in the literature regarding adult identification of infant vocalization. Authors of the present study collected data from 626 undergraduate students who listened to 100-500 ms audio clips of infant vocalization. Researchers asked participants to identify infants in the audio clips as male/female, English/non-English, and 0-7 months/8-18 months/19-36 months of age. Participants were unable to determine the sex of the infant better than chance but were able to determine the infant’s language and age significantly better than chance, t (463)= 4.4618, p < .001, and t (463) = 17.714, p < .001, respectively. Exploratory follow-up analyses did not reveal an effect of caregiving experience, childcare experience, or participant gender on a participants’ ability to correctly identify the infant’s age or language. This research has implications for determining what is and is not perceivable in infant vocalizations. This is an underrepresented topic in infant research as most work has demonstrated what infants can perceive; not what caregivers can. This is an important contribution because infant language development has been demonstrated to include a complex social dynamic between adults and infants.

Addressing publication bias in meta-analysis: Empirical findings from community-augmented meta-analyses of infant language development

Meta-analyses are an indispensable research synthesis tool for characterizing bodies of literature and advancing theories. One important open question concerns the inclusion of unpublished data into meta-analyses. Finding such studies can be effortful, but their exclusion potentially leads to consequential biases like overestimation of a literature’s mean effect. We address two key questions using MetaLab, a collection of community-augmented meta-analyses focused on developmental psychology. First, we assess to what extent these datasets include grey literature, and by what search strategies they are unearthed. An average of 11% of datapoints are from unpublished literature, and that standard search strategies like database searches, complemented with individualized approaches like including authors’ own data, contribute the majority of this literature. Second, we analyze the effect of including versus excluding unpublished literature on estimates of effect size and publication bias, and find this decision does not affect outcomes. We discuss lessons learned and implications.

Parents should keep talking to boost infant language development

Children from low socioeconomic status (SES) backgrounds tend to have poorer language skills when starting school than those from higher SES backgrounds. Now, data shows that increasing the amount of “contingent talk”— whereby a caregiver talks about objects that an infant is directly focusing on — within an infant’s first year of life promotes a wide vocabulary later in infancy.

Educating Parents About Infant Language Development: A Randomized Controlled Trial

A total of 427 women (aged 18-45 years) who delivered a singleton neonate without serious medical complications were randomized to watch either an educational intervention (n = 225) or the sudden infant death syndrome (n = 202) video. Linear mixed models showed that the intervention women significantly gained knowledge over time. Knowledge gain was largest among high–socioeconomic status (high-SES) and middle-SES English-speaking, smaller among low-SES Spanish-speaking, and nonsignificant among low-SES English-speaking women. Analysis of deviance revealed that the intervention women of all SES learned strategies fostering secure attachment and language acquisition. Participants considered watching an educational video alongside the universal newborn hearing screening (UNHS) conveniently timed. The intervention women were more likely than the control women to recognize the importance of timely UNHS follow-up.