Multi-object Data Integration in the Study of Primary Progressive Aphasia

TL;DR

This paper introduces a Bayesian framework for integrating brain connectome networks and gray matter images to identify regions related to speech loss in primary progressive aphasia, providing new neurodegenerative insights.

Contribution

It develops a novel integrated object response regression model with a prior that combines network and structural image data for PPA analysis.

Findings

Identifies brain regions significantly related to speech rate.

Provides uncertainty quantification for region associations.

Offers new neurodegenerative pattern insights in PPA.

Abstract

This article focuses on a multi-modal imaging data application where structural/anatomical information from gray matter (GM) and brain connectivity information in the form of a brain connectome network from functional magnetic resonance imaging (fMRI) are available for a number of subjects with different degrees of primary progressive aphasia (PPA), a neurodegenerative disorder (ND) measured through a speech rate measure on motor speech loss. The clinical/scientific goal in this study becomes the identification of brain regions of interest significantly related to the speech rate measure to gain insight into ND patterns. Viewing the brain connectome network and GM images as objects, we develop an integrated object response regression framework of network and GM images on the speech rate measure. A novel integrated prior formulation is proposed on network and structural image coefficients in order to exploit network information of the brain connectome while leveraging the interconnections among the two objects. The principled Bayesian framework allows the characterization of uncertainty in ascertaining a region being actively related to the speech rate measure. Our framework yields new insights into the relationship of brain regions associated with PPA, offering a deeper understanding of neuro-degenerative patterns of PPA. The supplementary file adds details about posterior computation and additional empirical results.