28 May 2017 to 2 June 2017
Queen's University
America/Toronto timezone
Welcome to the 2017 CAP Congress! / Bienvenue au congrès de l'ACP 2017!

Generalized Ising model and the dimensionality of the Brain

29 May 2017, 14:00
15m
Botterell B143 (Queen's University)

Botterell B143

Queen's University

CLOSED - Oral (Student, In Competition) / Orale (Étudiant(e), inscrit à la compétition) Physics in Medicine and Biology / Physique en médecine et en biologie (DPMB-DPMB) M3-4 Medical Imaging (DPMB) | Imagerie médicale (DPMB)

Speaker

Pubuditha Abeyasinghe (Western University)

Description

There are important evidences that spontaneous fluctuations of the brain are sustained by a structural architecture of axonal fiber bundles. As recently suggested, this well-defined fiber distribution could be highly informative to understand the underlying principles of spontaneous fluctuations as well as to infer the functional connectivity patterns of the brain. Various models have been employed to investigate the structure function relationship of the brain. In this work we implemented the generalized Ising model using the fiber distribution as the input and compared its outcome with the empirical functional connectivity and investigated its properties. A simpler 2-dimensional classical Ising model was used as the baseline model. Thermodynamic properties, such as the magnetic susceptibility and the specific heat, illustrated a phase transition from ordered phase to the disordered phase at the critical temperature. Furthermore, graph properties were extracted from the simulated functional patterns and compared with the empirically created graph. The two graph properties, global degree and global efficiency, clearly depicted a maximum at criticality. Additionally, the generalized Ising model exhibited the emergence of the resting state networks at the critical temperature, thus suggesting its capability to predict the spontaneous fluctuations of the brain at criticality from the anatomical fiber distribution. Despite the contrast between the input structural connectivities, both models exhibited similar behaviour of the global properties such as the global degree and efficiency. This could be explained by the notion of both models being in the same universality class obeying the same scaling relations. This leads to the calculation of the dimensionality of the Brain which could be used to explain the behaviour of the model around criticality. By following this procedure it is possible to investigate properties of other systems in the same universality class to better understand the behaviour of the systems.

Primary authors

Dr Andrea Soddu (Western University) Pubuditha Abeyasinghe (Western University)

Co-authors

Dr Adrian Owen (Western University) Mr Demetrius Paula (Western University) Mr Sina Khajehabdollahi (Western University) Dr Sree Ram Valluri (Western University)

Presentation materials