2. Effective Network connectivity during Verbal Working Memory:
Fu Yu Kwok1, Beth A O’Brien2, Stacey K H Tay3,4, Monika Sobczak-Edmans1,5 and Annabel Chen1,2,7,8*
1. Psychology, School of Social Sciences, Nanyang Technological University, Singapore
2. Centre for Research in Child Development, National Institute of Education, Nanyang Technological University, Singapore
3. Division of Paediatric Neurology, Department of Paediatrics, Khoo Teck Puat – National University Children’s Medical Institute, National University Health System, Singapore
4. Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
5. Department of Psychology, School of Applied Health Sciences, De Montfort University, Leicester, -United Kingdom
6. Centre for Research and Development in Learning, Nanyang Technological University, Singapore.
7. Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
8. Office of Education Research, National Institute of Education, Nanyang Technological University, Singapore
Abstract
Functional neuroimaging studies have advanced current understanding of changes in patterns of neuronal activation during verbal working memory with specific cerebrocerebellar functional networks identified. However, research examining the influence of typical and atypical neurodevelopment and task-related characteristics on functional connectivity in the context of verbal working memory is sparse. Thus, the present study conducted a two-fold investigation to elucidate the differences in effective network connectivity in typically developing children and that of young adults. Thereafter, the study compared the effect of dyslexia on the network connectivity patterns. Thirty-five young adults, ten neurotypical children and ten children with dyslexia underwent fMRI scanning while performing a modified Sternberg working memory task. Dynamic causal modelling (DCM) was employed to analyze the effective connectivity between co-activated brain regions. Results showed that (i) young adults and neurotypical children had patterns of activation for working memory with similar network connectivity, however (ii) children with dyslexia had a better fit for effective network connectivity models without cortical-subcortical modulatory connectivity. These findings provide a significant contribution to our present understanding of the effect of cross-sectional neurodevelopment and the impact of dyslexia on the effective network connectivity during verbal working memory.
Keywords: verbal working memory, fMRI, dynamic causal modelling, children, effective connectivity, dyslexia