Investigating cognitive ability using action-based models of structural brain networks

TL;DR

This paper develops and tests action-based generative models of brain networks, demonstrating that geometric constraints and non-local connections are key to understanding individual differences in cognitive ability.

Contribution

It introduces variants of action-based models combining topological and geometric factors, explaining variability in human connectomes and linking model parameters to cognitive ability.

Findings

Geometric constraints are essential for brain connectivity.

Models incorporating both topological and geometric factors explain individual variability.

Higher cognitive ability correlates with a tendency for long-range connections.

Abstract

Recent developments in network neuroscience have highlighted the importance of developing techniques for analyzing and modeling brain networks. A particularly powerful approach for studying complex neural systems is to formulate generative models that use wiring rules to synthesize networks closely resembling the topology of a given connectome. Successful models can highlight the principles by which a network is organized (identify structural features that arise from wiring rules versus those that emerge) and potentially uncover the mechanisms by which it grows and develops. Previous research has shown that such models can validate the effectiveness of spatial embedding and other (non-spatial) wiring rules in shaping the network topology of the human connectome. In this research, we propose variants of the action-based model that combine a variety of generative factors capable of explaining the topology of the human connectome. We test the descriptive validity of our models by evaluating their ability to explain between-subject variability. Our analysis provides evidence that geometric constraints are vital for connectivity between brain regions, and an action-based model relying on both topological and geometric properties can account for between-subject variability in structural network properties. Further, we test correlations between parameters of subject-optimized models and various measures of cognitive ability and find that higher cognitive ability is associated with an individual's tendency to form long-range or non-local connections.