Our research
We are currently studying how internal variation (e.g. in genetics, basic attentional processes) and external variation (e.g. exposure to different language environments, parenting) interact and constrain language and cognitive development in young typical and atypical populations.
01
EARLY PREDICTORS OF LATER DEVELOPMENTAL OUTCOMES IN DOWN SYNDROME, FRAGILE X SYNDROME, AND WILLIAMS SYNDROME
Our goal is to trace the developmental trajectories of later emerging, higher-level abilities (e.g., language) back to their basic-level roots (in, e.g., early visual attention) in children with Down syndrome, fragile X syndrome, and Williams syndrome. This is a longitudinal study (from 8 months to 10 years of age).
This is being funded by Autour des Williams, the British Academy, and The Waterloo Foundation.
D’Souza, D., D’Souza, H., & Karmiloff-Smith, A. (2017). Precursors to language development in typically and atypically developing infants and toddlers: the importance of embracing complexity. Journal of Child Language, 44, 591-627.
D’Souza, D., D’Souza, H., Horvath, K., Plunkett, K., & Karmiloff-Smith, A. (2020). Sleep is atypical across neurodevelopmental disorders in infants and toddlers: A cross-syndrome study. Research in Developmental Disabilities, 97, 103549.
D’Souza, D., D’Souza, H., Jones, E. J. H., & Karmiloff-Smith, A. (2020). Attentional abilities constrain language development: A cross-syndrome infant/toddler study. Developmental Science, e12961.
02
THE EFFECTS OF EXPOSURE TO A BILINGUAL ENVIRONMENT ON COGNITIVE DEVELOPMENT IN INFANTS
Bilinguals outperform monolinguals in nonverbal tasks of cognitive control and are less affected by age-associated cognitive decline (the bilingual advantage). Yet the neurocognitive mechanisms that underlie the bilingual advantage remain controversial. The most influential explanation is that managing two languages during language production constantly draws upon, and thus strengthens, domain general (i.e., not language-specific) cognitive control mechanisms. However, this theory cannot explain why a bilingual advantage is found in preverbal infants. Other mechanisms must be involved. We propose that mere exposure to a bilingual environment leads to experience-driven adaptations that confer both cognitive advantages and disadvantages. We are testing this hypothesis by using eye tracking technology and electroencephalography (EEG) to investigate neurocognitive processes in 7-month-old infants raised in bilingual vs. monolingual environments.
This is being funded by the British Academy.
D’Souza, D., & D’Souza, H. (2016). Bilingual language control mechanisms in anterior cingulate cortex and dorsolateral prefrontal cortex: A developmental perspective. The Journal of Neuroscience, 36, 5434-5436.
D’Souza, D., Brady, D., Haensel, J. X., & D’Souza, H. (2020). Is mere exposure enough? The effects of bilingual environments on infant cognitive development. Royal Society Open Science, 7, 7180191.
D’Souza, D., Brady, D., Haensel, J. X., & D’Souza, H. (2021). Early bilingual experience is associated with change detection ability in adults. Scientific Reports, 11, 2068.
D’Souza, D., & D’Souza, H. (2021). Bilingual adaptations in early development. Trends in Cognitive Sciences, 25, 727-729.
03
EMBODIED LANGUAGE DEVELOPMENT: USING HEAD-MOUNTED EYE TRACKERS AND LENA TO UNDERSTAND WORD LEARNING IN ATYPICALLY DEVELOPING TODDLERS
We will use head-mounted eye trackers and Language Environment Analysis (LENA) to elucidate developmental constraints on language learning in toddlers with Down syndrome and Williams syndrome.
This is being funded by Better Data (which is sponsored by the British Academy).
D’Souza, D., D’Souza, H., & Karmiloff-Smith, A. (2017). Precursors to language development in typically and atypically developing infants and toddlers: the importance of embracing complexity. Journal of Child Language, 44, 591-627.
04
THE RELATIONSHIP BETWEEN SLEEP AND LANGUAGE DEVELOPMENT
Children with neurodevelopmental disorders often present with language delay. Typical language development is constrained by numerous factors, including sleep. This is because sleep is important for physical and mental processes such as attention, memory, and motivation. Although little is known about sleep in atypically developing infants and toddlers, it is often disrupted in older (school age) children and adults with a neurodevelopmental disorder. We therefore hypothesise that sleep may be disrupted, and constrain early language development, in infants and toddlers with a neurodevelopmental disorder.
We have collected sleep, language, and cognitive data from 80 infants/toddlers with Down syndrome, fragile X syndrome, and Williams syndrome, and 50 typically developing controls. Our preliminary analyses suggest that sleep is highly disrupted in the atypically developing infants/toddlers. But is it related to their early language development?
This is being funded by The Waterloo Foundation.
D’Souza, D., D’Souza, H., Horvath, K., Plunkett, K., & Karmiloff-Smith, A. (2020). Sleep is atypical across neurodevelopmental disorders in infants and toddlers: A cross-syndrome study. Research in Developmental Disabilities, 97, 103549.