Stochastic Actor-Oriented Models of Functional and Structural Human Brain Networks in Aging

The human brain is a complex and dynamical system that changes throughout the lifetime. Non-invasive imaging techniques, including magnetic resonance imaging (MRI), allow for the measurement of large-scale functional and structural connectivity networks in the brain. Beyond trends, the dynamics across long timescales are still poorly understood. Our research aims to address the question of these long-term dynamics by carefully adapting and applying the stochastic actor-oriented model to brain networks derived from MRI data in an aging population. The resulting models of network change suggest that the brain is promoting modularity, local efficiency, and short-range connectivity during aging with more adaptive functional networks compared to structural networks. Differences between individuals with and without cognitive impairment suggest a disruption in the maintenance of key brain topology in the progression of cognitive impairment with age. These results are modulated by subnetwork and sex differences that contribute further to the emerging picture of long-term dynamics in aging.

Name thesis:degree_name

Master of Science (MSc)

Discipline thesis:degree_discipline

Physics & Astronomy

Grantor

Science

Year dc:date.issued

2026

Author dc:creator

• Garrison, Emma

Advisors dc:contributor.advisor

• Orlandi, Javier
• Sotero Diaz, Roberto C.

Committee members dc:contributor.committeemember

• Davidsen, Joern
• Bray, Signe Lauren
• Protzner, Andrea B.

• Complexity Science
• Graph Theory
• fMRI Networks
• DTI Networks
• Network Neuroscience
• Stochastic Modeling

Statement dc:rights

• Unless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

en

DOI

https://dx.doi.org/10.11575/PRISM/51092

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:1880/124135