Heat Kernels with Functional Connectomes Reveal Atypical Energy Transport in Peripheral Subnetworks in Autism
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Autism is increasing in prevalence and is a neurodevelopmental disorder characterised by impairments in communication skills and social behaviour. Connectomes enable a systems-level representation of the brain with recent interests in understanding the distributed nature of higher order cognitive function using modules or subnetworks. By dividing the connectome according to a central component of the brain critical for its function (it’s hub), we investigate network organisation in autism from hub through to peripheral subnetworks. We complement this analysis by extracting features of energy transport computed from heat kernels fitted with increasing time steps. This heat kernel framework is advantageous as it can capture the energy transported in all direct and indirect pathways between pair-wise regions over ’time’, with features that have correspondence to small-world properties. We apply our framework to resting-state functional MRI connectomes from a large, publically available autism dataset, ABIDE. We show that energy propagating through the brain over time are different between subnetworks, and that heat kernel features significantly differ between autism and controls. Furthermore, the hub was functionally preserved and similar to controls, however, increasing statistical significance between groups was found in increasingly peripheral subnetworks. Our results support the increasing opinion of non-hub regions playing an important role in functional organisation. This work shows that analysing autism by subnetworks with the heat kernel reflects the atypical activations in peripheral regions as alterations in energy dispersion and may provide useful features towards understanding the distributed impact of this disorder on the functional connectome.
KeywordsConnectome Functional network Heat kernel Diffusion equation Subnetworks Hubs Autism
This project has received funding from the American Heart Association and Children’s Heart Foundation Postdoctoral Fellowship, 19POST34380005 (AWC) and the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 753896 (MDS).
- 3.Chung, A.W., Ahtam, B., Grant, P.E., Im, K.: Rich club-based subnetworks in 16p11.2 deletion syndrome reveal differential structural alterations. In: Organization of Human Brain Mapping, Rome, Italy, p. 5204 (2019)Google Scholar
- 4.Chung, A.W., Mannix, R., Feldman, H.A., Grant, P.E., Im, K.: Longitudinal structural connectomic and rich-club analysis in adolescent mTBI reveals persistent, distributed brain alterations acutely through to one year post-injury. arXiv:1909.08071 [q-bio.NC], pp. 1–22, September 2019
- 5.Chung, A.W., Pesce, E., Monti, R.P., Montana, G.: Classifying HCP task-fMRI networks using heat kernels. In: 2016 International Workshop on Pattern Recognition in NeuroImaging (PRNI), pp. 1–4. IEEE (2016)Google Scholar
- 7.Chung, F.R., Graham, F.C.: Spectral Graph Theory, vol. 92. American Mathematical Society (1997)Google Scholar
- 17.Keown, C.L., Datko, M.C., Chen, C.P., Maximo, J.O., Jahedi, A., Müller, R.A.: Network organization is globally atypical in autism: a graph theory study of intrinsic functional connectivity. Biol. Psychiatry: Cogn. Neurosci. Neuroimaging 2(1), 66–75 (2017)Google Scholar
- 24.Schirmer, M.D., Chung, A.W.: Structural subnetwork evolution across the life-span: rich-club, feeder, seeder. In: Wu, G., Rekik, I., Schirmer, M.D., Chung, A.W., Munsell, B. (eds.) CNI 2018. LNCS, vol. 11083, pp. 136–145. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-00755-3_15CrossRefGoogle Scholar
- 25.Schirmer, M.D., Chung, A.W., Grant, P.E., Rost, N.S.: Network structural dependency in the human connectome across the life span. Netw. Neurosci. 1–15 (2018)Google Scholar
- 26.Schirmer, M.D., et al.: Rich-Club organization: an important determinant of functional outcome after acute ischemic stroke. Front. Neurol. 10, 956 (2019). https://doi.org/10.3389/fneur.2019.00956