Supervised brain node and network construction under voxel-level functional imaging

TL;DR

This paper introduces a supervised brain parcellation method that improves the predictive power of brain connectivity models by clustering voxels based on their relevance to behavioral outcomes, outperforming traditional unsupervised approaches.

Contribution

The paper presents SBP, a novel voxel-level brain parcellation technique that optimizes node definitions for better behavior prediction, integrating task-specific information.

Findings

SBP enhances out-of-sample predictive accuracy across datasets.

It outperforms traditional brain atlases in connectome-based predictions.

The method improves understanding of brain-behavior relationships.

Abstract

Recent advancements in understanding the brain's functional organization related to behavior have been pivotal, particularly in the development of predictive models based on brain connectivity. Traditional methods in this domain often involve a two-step process by first constructing a connectivity matrix from predefined brain regions, and then linking these connections to behaviors or clinical outcomes. However, these approaches with unsupervised node partitions predict outcomes inefficiently with independently established connectivity. In this paper, we introduce the Supervised Brain Parcellation (SBP), a brain node parcellation scheme informed by the downstream predictive task. With voxel-level functional time courses generated under resting-state or cognitive tasks as input, our approach clusters voxels into nodes in a manner that maximizes the correlation between inter-node connections and the behavioral outcome, while also accommodating intra-node homogeneity. We rigorously evaluate the SBP approach using resting-state and task-based fMRI data from both the Adolescent Brain Cognitive Development (ABCD) study and the Human Connectome Project (HCP). Our analyses show that SBP significantly improves out-of-sample connectome-based predictive performance compared to conventional step-wise methods under various brain atlases. This advancement holds promise for enhancing our understanding of brain functional architectures with behavior and establishing more informative network neuromarkers for clinical applications.