Abstract
Prior research points to a positive concurrent relationship between reasoning ability and both fronto-parietal structural connectivity, as measured by diffusion tensor imaging (e.g. Tamnes et al., 2010), and fronto-parietal functional connectivity, as measured by fMRI (e.g. Cocchi et al., 2014). Further, recent research demonstrates a link between reasoning ability and functional connectivity of two brain regions in particular: rostrolateral prefrontal cortex (RLPFC) and the inferior parietal lobe (IPL) (Wendelken et al., 2016). Here, we sought to investigate the concurrent and dynamic, lead-lag relationships between fronto-parietal structural connectivity, functional connectivity, and reasoning ability in humans. To this end, we combined three longitudinal developmental datasets with behavioral and neuroimaging data from 523 male and female participants between 6 and 22 years old. Cross-sectionally, reasoning ability was most strongly related to functional connectivity between RLPFC and IPL in adolescents and adults, but to fronto-parietal structural connectivity in children. Longitudinal analysis revealed that RLPFC-IPL structural connectivity, but not functional connectivity, was a positive predictor of future changes in reasoning ability. Moreover, we found that RLPFC-IPL structural connectivity at one time point positively predicted future changes in RLPFC-IPL functional connectivity, while in contrast, functional connectivity did not predict future changes in structural connectivity. Our results demonstrate the importance of strong white matter connectivity between RLPFC and IPL during middle childhood for the subsequent development of both robust functional connectivity and good reasoning ability.
SIGNIFICANCE STATEMENT
The human capacity for reasoning develops substantially during childhood and has a profound impact on achievement in school and in cognitively challenging careers. Reasoning ability depends on communication between lateral prefrontal and parietal cortices. Thus, to understand how this capacity develops, we examined the dynamic relationships over time between white matter tracts connecting fronto-parietal cortices (i.e., structural connectivity), coordinated fronto-parietal activation (functional connectivity) and reasoning ability in a large longitudinal sample of 6-22-year-olds. We found that greater fronto-parietal structural connectivity in childhood predicts future increases in both functional connectivity and reasoning ability, demonstrating the importance of white matter development during childhood for subsequent brain and cognitive functioning.
Footnotes
The authors declare no competing financial interests.
Funding for this research was provided by the National Science Foundation (BCS1558585). Funding for original data collection was provided by the National Institutes of Health (NINDS R01 NS057156, NIMH R01 MH091109, NICHD R01 HD067254). S.A.B.'s contribution was additionally supported by a Jacobs Foundation Research Fellowship. We thank former and current members of the Bunge, Ghetti, and Cutting laboratories for assistance with data collection. We also thank Yana Fandakova and Susan Whitfield-Gabrieli for feedback on the manuscript.
Jump to comment: