title: Directional connectivity of resting state human fMRI data using cascaded ICA-PDC analysis.
abstract: BACKGROUND
  Directional connectivity measures, such as partial directed coherence (PDC), give us means to explore effective connectivity in the human brain. By utilizing independent component analysis (ICA), the original data-set reduction was performed for further PDC analysis.
  
  
  OBJECTIVE
  To test this cascaded ICA-PDC approach in causality studies of human functional magnetic resonance imaging (fMRI) data.
  
  
  METHODS
  Resting state group data was imaged from 55 subjects using a 1.5 T scanner (TR 1800 ms, 250 volumes). Temporal concatenation group ICA in a probabilistic ICA and further repeatability runs (n = 200) were overtaken. The reduced data-set included the time series presentation of the following nine ICA components: secondary somatosensory cortex, inferior temporal gyrus, intracalcarine cortex, primary auditory cortex, amygdala, putamen and the frontal medial cortex, posterior cingulate cortex and precuneus, comprising the default mode network components. Re-normalized PDC (rPDC) values were computed to determine directional connectivity at the group level at each frequency.
  
  
  RESULTS
  The integrative role was suggested for precuneus while the role of major divergence region may be proposed to primary auditory cortex and amygdala.
  
  
  CONCLUSIONS
  This study demonstrates the potential of the cascaded ICA-PDC approach in directional connectivity studies of human fMRI.
authors: Department of Computer Science and Engineering, University of Oulu, Linnanmaa, Finland. Minna.Silfverhuth@oulu.fi
authors: Minna J
authors: MJ
authors: Silfverhuth
authors: Jukka
authors: J
authors: Remes
authors: Tuomo
authors: T
authors: Starck
authors: Juha
authors: J
authors: Nikkinen
authors: Juha
authors: J
authors: Veijola
authors: Osmo
authors: O
authors: Tervonen
authors: Vesa
authors: V
authors: Kiviniemi
mesh_terms: D001921:Brain / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology; D055815:Young Adult