Structural core of the executive control network: A high angular resolution diffusion MRI study.

Kai‐Kai Shen,Ralph Martins,Samantha Burnham,Matthew Lyon,Thomas Welton,Jurgen Fripp,Andrew N Mccorkindale,Greg T Sutherland,Stuart M Grieve

doi:10.1002/hbm.24870

Abstract

Executive function (EF) is a set of cognitive capabilities considered essential for successful daily living, and is negatively affected by ageing and neurodegenerative conditions. Underpinning EF performance are functional nodes in the executive control network (ECN), while the structural connectivity underlying this network is not well understood. In this paper, we evaluated the structural white matter tracts that interconnect the ECN and investigated their relationship to the EF performance. Using high‐angular resolution diffusion MRI data, we performed tractography analysis of structural connectivity in a cognitively normal cohort (n = 140), specifically targeting the connectivity between ECN nodes. Our data revealed the presence of a strongly‐connected “structural core” of the ECN comprising three components: interhemispheric frontal connections, a fronto‐parietal subnetwork and fronto‐striatal connections between right dorsolateral prefrontal cortex and right caudate. These pathways were strongly correlated with EF performance (p = .003). Post‐hoc analysis of subregions within the significant ECN connections showed that these effects were driven by a highly specific subset of interconnected cortical regions. The structural core subnetwork of the functional ECN may be an important feature crucial to a better future understanding of human cognition and behaviour.

Highlights

Executive function (EF) outlines a central set of cognitive capabilities that are essential to successful daily living
Our study reveals the presence of a “structural core” in the executive control network (ECN), providing convergent evidence linking components of the functionallydefined ECN with structural network strength
We suggest that this “structural core” network may represent the static architecture from which the dynamic functional connectivity underlying EF emerges (Park & Friston, 2013)

Summary

Introduction

Executive function (EF) outlines a central set of cognitive capabilities that are essential to successful daily living. EF refers to a collection of higher order processes that guide thoughts and behaviours towards achieving a specific goal (Niendam et al, 2012). It includes processes such as working memory, inhibition of prepotent responses, attentional control, planning and flexibility of switching between different goals. EF contributes to the coordination of activities across a wide range of cortical and subcortical brain structures that would make them vulnerable to reduced communication efficiency. Investigations into EF using functional MRI (fMRI) experiments have identified the activation patterns of an executive control network (ECN) subserving EF tasks (Niendam et al, 2012). It is critical to develop a better understanding of the neural substrates of EF, including the ECN

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