title: The intrinsic geometry of the human brain connectome.
abstract: This paper describes novel methods for constructing the intrinsic geometry of the human brain connectome using dimensionality-reduction techniques. We posit that the high-dimensional, complex geometry that represents this intrinsic topology can be mathematically embedded into lower dimensions using coupling patterns encoded in the corresponding brain connectivity graphs. We tested both linear and nonlinear dimensionality-reduction techniques using the diffusion-weighted structural connectome data acquired from a sample of healthy subjects. Results supported the nonlinearity of brain connectivity data, as linear reduction techniques such as the multidimensional scaling yielded inferior lower-dimensional embeddings. To further validate our results, we demonstrated that for tractography-derived structural connectome more influential regions such as rich-club members of the brain are more centrally mapped or embedded. Further, abnormal brain connectivity can be visually understood by inspecting the altered geometry of these three-dimensional (3D) embeddings that represent the topology of the human brain, as illustrated using simulated lesion studies of both targeted and random removal. Last, in order to visualize brain's intrinsic topology we have developed software that is compatible with virtual reality technologies, thus allowing researchers to collaboratively and interactively explore and manipulate brain connectome data.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 218 SEO, 851 S Morgan St, Chicago, 60607, IL, USA.|Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Allen Q
authors.initials: AQ
authors.lastname: Ye
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Olusola A
authors.initials: OA
authors.lastname: Ajilore
authors.affiliation: Department of Computer Science, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Conte
authors.affiliation: Department of Computer Science, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Johnson
authors.initials: J
authors.lastname: GadElkarim
authors.affiliation: Department of Computer Science, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Galen
authors.initials: G
authors.lastname: Thomas-Ramos
authors.affiliation: Computer Engineering Program, Engineering and Technology Department, University of Wisconsin-Stout, Menomonie, WI, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhan
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 218 SEO, 851 S Morgan St, Chicago, 60607, IL, USA.|Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA.|Department of Radiology, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Shaolin
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Anand
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 218 SEO, 851 S Morgan St, Chicago, 60607, IL, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Magin
authors.affiliation: Department of Computer Science, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Angus
authors.initials: A
authors.lastname: G Forbes
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, 218 SEO, 851 S Morgan St, Chicago, 60607, IL, USA. alexfeuillet@gmail.com.|Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA. alexfeuillet@gmail.com.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Leow
keywords: Connectomics; Diffusion MRI; Dimensionality reduction; Tractography; Virtual reality