Exploring language and cognitive trajectories in preterm and full-term bilingual infants: A comprehensive study.

Background- There is a rising trend in the number of infants born prematurely (Bliss, 2023), that is before 37 weeks gestation. In 2020, there were 13.4 million infants worldwide, that is more than 1 in 10 births (World Health Organisation, 2023). The early years of life are a critical period for the foundational development of language and cognition.

Preterm children, more so than full term children, are at risk of developmental delays in both language and cognitive domains (You et al., 2019). They tend to achieve lower mean scores on intelligence scales, experiencing challenges in attention, visuospatial processing, spatial working memory, and language (Caravale, 2005).

Some research indicates that multilingualism may have an additional diminishing impact on the cognitive and verbal development of very preterm/extremely preterm children at the adjusted ages of two and five years (Van Veen et al., 2019). However, contradicting research suggests that bilingualism has the potential to enhance developmental outcomes, cognitive function, and school performance in children born preterm (Head et al., 2014).

Therefore, with ever-increasing numbers of children worldwide growing up bilingual (Byers-Heinlein et al., 2019) and the rising prevalence of households communicating in languages other than English within their homes (Gration, 2021), it is important to establish the exact role of bilingualism on preterm children's cognitive and language development.

The language and cognitive development of both full-term and preterm born children is impacted by various environmental factors such as language exposure, socioeconomic status (SES), and parental involvement as highlighted by Largo et al (1986). Underexposure to significant auditory stimuli and nonoptimal infant-caregiver interactions during a prolonged stay in a neonatal intensive care unit (NICU) have been linked to poorer language outcomes (Vandormael et al., 2019).

Meanwhile sociodemographic variables play a pivotal role in determining language development (Chan et al., 2022), such as SES which is reported as one of the major influences on cognitive outcomes in very preterm (VP) children (Wolke et al., 2019). It is vital to investigate whether bilingualism moderates the effects of these environmental factors on language development.

The goal of this project is to take into account these aspects, therefore providing more nuanced findings than existing studies on bilingual preterm infants.

Research aims-The aim of this project is to contribute to a comprehensive understanding of language and cognitive developmental trajectories in bilingual preterm and full-term infants. The study aims to contribute insights that go beyond specific linguistic contexts, enriching our understanding of early childhood development.

Method-Around 160 bilingual and 160 monolingual infants aged between 10 months-36 months will be recruited. This age range represents a critical period for language and cognitive development. The sample size is based on previous relevant studies (Yaari et al,2018). This project will implement parental-report and standardised measures to gain information and data on the linguistic and cognitive abilities of the infants.

Outcomes & Significant- The goal is to produce research outcomes that not only contribute to the academic field but also have real-world implications which will be instrumental in shaping evidence-based interventions and support systems that meet the unique needs of infants born prematurely in bilingual environments, with an aim to link research, policy and practice.