title: Complex network analysis of resting-state fMRI of the brain.
abstract: Due to the fact that the brain activity hardly ever diminishes in healthy individuals, analysis of resting state functionality of the brain seems pertinent. Various resting state networks are active inside the idle brain at any time. Based on various neuro-imaging studies, it is understood that various structurally distant regions of the brain could be functionally connected. Regions of the brain, that are functionally connected, during rest constitutes to the resting state network. In the present study, we employed the complex network measures to estimate the presence of community structures within a network. Such estimate is named as modularity. Instead of using a traditional correlation matrix, we used a coherence matrix taken from the causality measure between different nodes. Our results show that in prolonged resting state the modularity starts to decrease. This decrease was observed in all the resting state networks and on both sides of the brain. Our study highlights the usage of coherence matrix instead of correlation matrix for complex network analysis.
authors.forename: Abdul Rauf
authors.initials: AR
authors.lastname: Anwar
authors.forename: Muhammad Yousaf
authors.initials: MY
authors.lastname: Hashmy
authors.forename: Bilal
authors.initials: B
authors.lastname: Imran
authors.forename: Muhammad Hussnain
authors.initials: MH
authors.lastname: Riaz
authors.forename: Sabtain Muhammad Muntazir
authors.initials: SM
authors.lastname: Mehdi
authors.forename: Makii
authors.initials: M
authors.lastname: Muthalib
authors.forename: Stephane
authors.initials: S
authors.lastname: Perrey
authors.forename: Gunther
authors.initials: G
authors.lastname: Deuschl
authors.forename: Sergiu
authors.initials: S
authors.lastname: Groppa
authors.forename: Muthuraman
authors.initials: M
authors.lastname: Muthuraman
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D033281:Nontherapeutic Human Experimentation; D012146:Rest / Q000502:physiology*