Dissociating the Effects of Age and Schooling on Neurocognitive Development
The SAND Study
Entering formal schooling is a major transition in almost every child’s life. In this line of work, we examine different cognitive domains (e.g., episodic memory, executive functions) that may be affected by schooling. In episodic memory, we found that while there is a general improvement of memory encoding across time around 5-7 years of age, this improvement could not be attributed to formal schooling (Nolden et al., 2021). However, aspects of executive functions are more strongly affected by formal schooling. For example, one year of being in the first-grade leads to improved cognitive control (i.e. the ability to orchestrate thought and action in accordance with internal goals), as well as an increase in the activation of right posterior parietal cortex, a brain region important for sustained attention (see Brod, Bunge, & Shing, 2017, Psych. Sci.).
In this follow-up study, we tackle the questions of whether there are antecedents and consequences to such schooling-specific neurocognitive changes, for example in predicting academic outcomes over time. Together with our collaborators Dr. Eva Rafetseder (University of Stirling, UK) and Dr. Sobanawartiny Wijeakumar (University of Nottingham, UK) we are conducting a longitudinal study that assesses brain functions, cognitive abilities, and academic performance in a sample of children similar in age but different in year of school entrance. Data was collected on children in their homes in Scotland across three consecutive years. In Scotland, school commencement dates fall in August each year, with the school starting year cohort consisting of children born between the beginning of March in one year (aged 5.5) and the end of February (aged 4.5) of the following year. However, parents of children born in January and February each year can choose to enroll their child into school or defer their entry until the following year, and these requests are automatically approved. This results in two groups of children who are close in age but who differ in their experience in a school context, allowing us to isolate the effects of schooling.
At the first timepoint, prior to the children starting school, we investigated the neurocognition of two types of executive function, namely, visual working memory and inhibitory control. Specifically, children were categorised into high-performing (HP) and low-performing (LP) groups based on task performance, and group differences in brain activation were investigated. We found that, LPs increasingly activated left frontal and bilateral parietal cortices when their visual working memory capacity was challenged. Further, we found that activation in the left parietal cortex partially mediated the association between parent-reported stressful life events and performance on the visual working memory task (see McKay et al., 2021a). Similarly, for the inhibitory control task, we found that LPs increasingly activated channels in the bilateral frontal and parietal cortices when their inhibitory processes were strained. Taken together, children with lower executive functions show less efficient brain activation when under task challenge.
To isolate the unique contributions of schooling on development, we also examined the longitudinal development of visual working memory and inhibitory control and their neural correlates, and how these differ by the schooling experience. We found that children who attended one full year of schooling (P1) improved more in the visual working memory task than children who stayed in kindergarten (KG). Additionally, P1 children who began the year with greater visual working memory gained more in vocabulary across the school year. We also examined two types of inhibitory control, namely response inhibition and response monitoring (see McKay et al., 2021b). No schooling-related effects were found in response inhibition, however, P1 children, compared to KG children, showed a greater change over time in activation related to more efficient response monitoring in the bilateral frontal cortex. Further, the change in left frontal activation difference underlying response monitoring showed a small positive association with mathematical ability. Taken together, schooling-specific neurocognitive changes observed in executive functions can predict some aspects of academic performance across the first school year.
This study is funded by a Jacobs Foundation Research Fellowship for Prof. Dr. Yee Lee Shing. For more information, please visit https://jacobsfoundation.org/en/activity/jacobs-foundation-research-fellows/
Nolden, S., Brod, G., Meyer, A.-K., Fandakova, Y., & Shing, Y. L. (2021). Neural correlates of successful memory encoding in kindergarten and early elementary school children: Longitudinal trends and effects of schooling. Cerebral Cortex, 31(8), 3764–3779. doi: 10.1093/cercor/bhab046.
McKay, C., Shing, Y. L., Rafetseder, E., & Wijeakumar, S. (2021a). Home assessment of visual working memory in pre-schoolers reveals associations between behavior, brain activation and parent reports of life stress. Developmental Science. Full text
McKay, C., Wijeakumar, S., Rafetseder, E., & Shing, Y. L. (2021b). Disentangling age and schooling effects on inhibitory development: An fNIRS investigation. biorxiv
Brod, G., Bunge, S. A., & Shing, Y. L. (2017). Does one year of schooling improve children's cognitive control and alter associated brain activation? Psychological Science, 28, 967-978, doi:10.1177/0956797617699838. Full text