Poster #4 - The unity and diversity of brain connectivity underlying executive function tasks

• In Event: Poster Session 07

Abstract

Executive function (EF) is a broad set of cognitive processes that drive attention and control abilities, and aid in facilitating goal directed behaviors. EF ability is predictive of numerous important life outcomes in childhood and beyond, including academic success, mental health, and physical health. EF is exerted across many different domains, such as inhibition, working memory, and switching. These domains share common and unique variance and can be described within a unity (common) and diversity (unique) framework of EF. The neurobiological systems that support EF are in place as early as late childhood. These brain systems have been shown to be active in the same way across different EF domains (unity). However, there are also unique neurobiological mechanisms underlying different domains (diversity). EF domains have been found to mature at different rates and relate to different mental health disorders. Therefore, understanding diversity in the neurobiological mechanisms of EF is crucial for promoting healthy development.

Here we examine the neurobiological diversity of EF in childhood and adolescence by analyzing patterns of functional connectivity in the developing brain (n=62, Mage= 12.19, age range= 8.77-17.20, 30 F). We tested whether functional connectivity differed across four cognitive states (three tasks tapping into different EF domains, and resting-state). All participants completed at least one run of a resting-state task, a working memory task, a cognitive flexibility task, and an inhibition task while in a MRI scanner. We estimated functional connectivity within each of the 4 states by computing the pairwise correlations of time courses derived from 333 cortical parcels spanning the whole brain. This resulted in four correlation matrices per person (one for each state). We then computed two graph metrics for each state, global efficiency; quantifying the integration between brain regions, and modularity; quantifying how the brain segregates into distinct systems. Mixed effects models were used to test for differences in graph metrics between rest and the three EF tasks.

We found brain connectivity differed across the four states. Global efficiency at rest was significantly lower than during the working memory and inhibition tasks. We observed the lowest global efficiency during the cognitive flexibility task. Across the 4 cognitive states, we found that modularity at rest was significantly different from modularity during a working memory task and an inhibition task, with rest having the highest modularity, and the working memory task having the lowest modularity. We also found age was related to brain connectivity, with older youth having higher modularity during the cognitive flexibility and inhibition tasks, and lower global efficiency during the inhibition task. Taken together, this work shows the brain significantly changes in its functional organization across EF tasks. However, the nature of this change differs by EF domain, with working memory and inhibition requiring more integration, and cognitive flexibility requiring more segregation. Additionally, age was related to functional connectivity during some EF domains but not others, suggesting distinct maturational trajectories of brain function.

Authors

• Blaire Porter, University of Texas at Austin
  Presenting Author

• Tehila Nugiel, University of Texas at Austin

• Damion Demeter, University of Texas at Austin

• Eliya Ben-Asher, University of Texas at Austin

• Jessica A Church, University of Texas at Austin