NWO VIDI Research proposal - The Neurocognitive and Affective Foundation of Individual Variability in Language Development

Language is essential for communication, learning, and social interactions, shaping both individuals' daily lives and society at large. While children typically acquire language more easily than adults, significant individual differences exist in both groups. For instance, some children experience delays in first language development, and some adults excel at learning multiple languages later in life. Understanding why some people acquire language effortlessly while others struggle is crucial, especially given language's profound role in human development. Yet, the exact reasons behind these differences and their long-term
impact remain unclear. This proposal aims to address this gap by presenting a new theory of language learning that incorporates often-overlooked sensorimotor and emotional mechanisms into a unified neurocognitive framework. I will conduct experimental studies to investigate how individual differences in cognitive functions, speech-motor synchrony, and intrinsic reward
responses to speech (such as, feelings of pleasure) associate with implicit pattern
detection during speech listening, which is an essential early step in spoken language acquisition. Using advanced techniques such as brain stimulation, electrophysiology (EEG and skin conductance), and cognitive-load manipulations, I will more specifically investigate whether differences in the development of higher executive functions (which vary across individuals) influence the ability to spontaneously synchronize speech-motor rhythms (such as tongue, lip, and jaw movements) with speech-audio rhythms as well as internal pleasure during learning. This research will enhance our understanding of why spoken language acquisition varies across both developmental stages and individuals.
In the long term, this research will have broad scientific and societal relevance by improving our understanding of how language is acquired in the brain and reshaping language education. The findings will lead to tailored strategies for individuals facing language-learning challenges, supporting linguistic inclusion and accessibility.