Abstract
Objective: A graph theoretical approach provides a powerful framework for discovering potential biomarkers of psychotic disorders. Comparing the brain graphs of the control and patient groups can help us to discover changes in mental disorders in a more convenient way. In this paper, we propose a novel tool to identify missing links associated with blocked paths (segregation) and new links associated with additional paths (abnormal integration) in estimated patient group's time-varying graphs. We highlight the approach in an example application to the resting-state functional magnetic resonance imaging (fMRI) data of schizophrenia (SZ) patients. Methods: We first estimated whole-brain functional connectivity dynamics using a combination of spatial independent component analysis (ICA), sliding time window, and k-means clustering of windowed correlation matrices on resting-state fMRI data. The clusters are regarded as functional connectivity states, and each of them includes time intervals exhibiting similar connectivity patterns. We then estimated a Gaussian graphical model (GGM) for each state for both groups. To evaluate this approach, we compared different paths between brain components (nodes) of SZ and control groups' graphs within each state by using the concept of connected components in graph theory. Results: We identified missing edges associated with disconnectivity (disconnectors) and showed there are additional edges in the SZ group graph that contribute to creating new paths in brain graphs. Conclusion: The proposed approach provides a tool for extracting time-varying graphs and identifying disconnectors associated with disconnectivity (absence of paths) and also connectors associated with abnormal integration (additional paths) in patient group graphs. Significance: We detected several missing links in SZ, both within and between functional domains, in particular within the subcortical (3 links) and somatomotor (4 links) domains. Interestingly, our proposed method identified new links within the somatomotor domain which may be related to a compensatory response in patients that warrants future study.
Original language | English (US) |
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Title of host publication | Proceedings - IEEE 20th International Conference on Bioinformatics and Bioengineering, BIBE 2020 |
Publisher | Institute of Electrical and Electronics Engineers Inc. |
Pages | 417-424 |
Number of pages | 8 |
ISBN (Electronic) | 9781728195742 |
DOIs | |
State | Published - Oct 2020 |
Event | 20th IEEE International Conference on Bioinformatics and Bioengineering, BIBE 2020 - Virtual, Cincinnati, United States Duration: Oct 26 2020 → Oct 28 2020 |
Publication series
Name | Proceedings - IEEE 20th International Conference on Bioinformatics and Bioengineering, BIBE 2020 |
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Conference
Conference | 20th IEEE International Conference on Bioinformatics and Bioengineering, BIBE 2020 |
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Country/Territory | United States |
City | Virtual, Cincinnati |
Period | 10/26/20 → 10/28/20 |
Bibliographical note
Funding Information:This work was supported in part by NIH under grants R01EB020407, R01EB006841, P20GM103472, P30GM122734 and NSF under grant 1539067.
Publisher Copyright:
© 2020 IEEE.
Keywords
- Brain graph
- Gaussian graphical model
- joint estimation
- partial correlation
- resting state fMRI
- schizophrenia