A mechanistic model of connector hubs, modularity and cognition, nature human behaviour

Something just fascinates me about connector hubs. We know they are diversely connected across the brain’s communities. However, I wanted a mechanistic understanding of their function, not just their topology. I also wanted to know if there is a general optimal network structure for cognitive processing that involves modularity and strong connector hubs.

My two previous papers found evidence that connector hubs integrate across the brain’s communities and coordinate connectivity between the communities. However, we didn’t have any mechanistic evidence for this. We inferred their function based on the types of connections that connector hubs have, a generative model of connector hubs (read more here), and their activity profile during different cognitive tasks (read more here).

In this paper, we present a mechanistic model of connector hubs and how they support cognition by leveraging individual differences in hub connectivity and cognition. Critically, we find that there is a general optimal network structure for cognitive performance—individuals with diversely connected hubs and consequent modular brain networks exhibit increased cognitive performance, regardless of the task. Critically, we find evidence consistent with a mechanistic model in which connector hubs tune the connectivity of their neighbours to be more modular while allowing for task appropriate information integration across communities, which increases global modularity and cognitive performance. Finally, we show that a model of hub connectivity accurately predicts the cognitive performance of 476 individuals in four distinct tasks.

In sum, this work demonstrates that the connectivity of connector hubs and the brain’s overall network structure are strongly related to ongoing cognition. Moreover, even though we don’t have “causal” findings, we test a very specific mechanistic model of how connector hubs function.

 

A mechanistic model of connector hubs, modularity and cognition
Maxwell A. Bertolero, B. T. Thomas Yeo, Danielle S. Bassett & Mark D’Esposito.
Nature Human Behaviour, volume 2, pages 765–777 (2018) https://www.nature.com/articles/s41562-018-0420-6