Multisensory integration processing during olfactory-visual stimulation-An fMRI graph theoretical network analysis

Hum Brain Mapp. 2018 Sep;39(9):3713-3727. doi: 10.1002/hbm.24206. Epub 2018 May 7.


In this study, we aimed to understand how whole-brain neural networks compute sensory information integration based on the olfactory and visual system. Task-related functional magnetic resonance imaging (fMRI) data was obtained during unimodal and bimodal sensory stimulation. Based on the identification of multisensory integration processing (MIP) specific hub-like network nodes analyzed with network-based statistics using region-of-interest based connectivity matrices, we conclude the following brain areas to be important for processing the presented bimodal sensory information: right precuneus connected contralaterally to the supramarginal gyrus for memory-related imagery and phonology retrieval, and the left middle occipital gyrus connected ipsilaterally to the inferior frontal gyrus via the inferior fronto-occipital fasciculus including functional aspects of working memory. Applied graph theory for quantification of the resulting complex network topologies indicates a significantly increased global efficiency and clustering coefficient in networks including aspects of MIP reflecting a simultaneous better integration and segregation. Graph theoretical analysis of positive and negative network correlations allowing for inferences about excitatory and inhibitory network architectures revealed-not significant, but very consistent-that MIP-specific neural networks are dominated by inhibitory relationships between brain regions involved in stimulus processing.

Keywords: beta-series correlation; functional connectivity; functional imaging; graph theory; network efficiency; network statistics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Connectome*
  • Emotions
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Models, Neurological
  • Nerve Net / diagnostic imaging
  • Nerve Net / physiology*
  • Odorants
  • Olfactory Perception / physiology*
  • Photic Stimulation
  • Visual Perception / physiology*
  • Young Adult