Infant Adaptations to Bilingual Environments

双语是一个日益重要的社会和政治问题。目前，在英国出生的儿童中，有三分之一的父母至少有一人在外国出生，20%的小学生将英语作为第二语言（ONS，2021）。随着移民和多元文化社区的兴起，以及中东、亚洲和其他地区经济的快速增长，双语已成为从小型组织（例如，学校和本地企业）到大的（例如，联合国）。为了满足这方面的需求，并保持文化和身份，政府已采取措施在社区推行双语制度（例如，威尔士政府）。希望这些举措将带来长期的社会经济和文化效益。但是，双语现象的普遍存在对儿童的发展有什么影响呢？这个问题变得越来越重要，因为我的实验室的证据（与加拿大、美国和西班牙的实验室最近的证据相吻合）表明，暴露在双语环境中会影响婴儿的认知发展。尽管这个婴儿研究的新领域正在蓬勃发展，但它没有方向或理论。因此，我介绍了一个理论框架的基础上，已知的发展限制，可以整合新兴的经验证据，并改变新兴领域。根据这一理论（D'Souza & D'Souza，2021），双语婴儿通过更快、更频繁地转换注意力来适应更复杂的环境。这些适应帮助婴儿引导他们的语言学习，让他们迅速转移注意力到扬声器的嘴唇运动。这种适应也导致双语婴儿比单语婴儿更多地探索他们的环境，影响学习和发展。为了验证这一理论并整合研究结果，我将在发育的关键时期（5个月、7.5个月和10个月）对婴儿进行纵向研究。首先，我将分析幼儿家庭和语言环境的复杂性。了解孩子成长的环境对了解孩子将如何适应环境至关重要。其次，我将观察婴儿如何适应不同的环境（例如，双语婴儿比单语婴儿探索更多吗？第三，我将使用神经成像来测量婴儿在探索不同环境时的大脑活动。这将阐明相关的神经过程。最后，我将使用计算机建模来整合观测和实验数据。这将有助于我们解释双语对婴儿大脑和认知发展的影响。为了测试我的理论在多大程度上可以应用，我将研究来自伦敦三个不同社区（阿尔巴尼亚人、立陶宛人、孟加拉人）以及西班牙和新加坡社区的婴儿。4年后，我将扩大研究人群，包括墨西哥和巴布亚新几内亚的偏远农村社区。我的研究将导致我们对婴儿发育的理解发生重大变化，因为它将大脑和认知实验数据与自然主义的观察数据结合在一起。奖学金也将为我提供机会，发展我的数学和计算技能，并在不同的文化背景下测试我的理论。这将有助于我们了解双语对儿童发展的影响，最终解决当今社会的主要问题之一。

Bilingualism is an increasingly important issue in society and politics. Currently, 1 in 3 children born in the UK have at least one foreign-born parent and 20% of children in primary school speak English as an additional language (ONS, 2021). With the rise of immigration and diverse multicultural communities, and the rapid growth of economies in the Middle East, Asia, and elsewhere, bilingualism has become a priority for organisations that range from the small (e.g., schools and local businesses) to the large (e.g., the United Nations). To meet this demand, and to maintain culture and identity, initiatives have been set up to implement bilingualism in the community (e.g., by the Welsh government). It is hoped that these initiatives will provide long term socioeconomic and cultural benefits. But what effect does widespread bilingualism have on children's development? This question is becoming pertinent, because evidence from my lab (which dovetails with more recent evidence from labs in Canada, the USA and Spain) suggest that exposure to a bilingual environment can affect the infant's cognitive development.Although this new field of infant research is blossoming, it has no direction or theory. I have therefore introduced a theoretical framework based on known developmental constraints that can integrate the burgeoning empirical evidence and transform the emerging field. According to this theory (D'Souza & D'Souza, 2021), bilingual infants adapt to their more complex environments by switching attention faster and more frequently. These adaptations help the infant to bootstrap their language learning by allowing them to rapidly shift attention to speakers' lip movements. The adaptations also lead the bilingual infant to explore their environment more than the monolingual infant, impacting learning and development.To test this theory and integrate findings, I will study infants longitudinally at a crucial period in development (5, 7.5, and 10 months). First, I will analyse the complexity of the infants' home and language environment. Understanding the context in which the child is growing up is crucial to understanding how the child will adapt to it. Second, I will observe how the infants adapt to different environments (e.g., do bilingual infants explore more than monolingual infants?). Third, I will use neuroimaging to measure the infants' brain activity as they explore different environments. This will elucidate relevant neural processes. Finally, I will use computer modelling to integrate the observational and experimental data. This will help us to explain the effect of bilingualism on infant brain and cognitive development.To test the extent to which my theory can be applied, I will study infants from three different communities in London (Albanian, Lithuanian, Bangladeshi) as well as communities in Spain and Singapore. After 4 years, I will expand the population studied to include remote rural communities in Mexico and Papua New Guinea.My research will lead to a step-change in our understanding of infant development, because it combines brain and cognitive experimental data with naturalistic observational data in the same group of children over time. The fellowship will also provide me with the opportunity to develop my mathematical and computational skills, and test my theories across different cultural contexts. This will help us to understand the effect of bilingualism on child development, ultimately addressing one of the major issues in current society.