Breakdown of the brain's functional network modularity with awareness

Proc Natl Acad Sci U S A. 2015 Mar 24;112(12):3799-804. doi: 10.1073/pnas.1414466112. Epub 2015 Mar 10.

Abstract

Neurobiological theories of awareness propose divergent accounts of the spatial extent of brain changes that support conscious perception. Whereas focal theories posit mostly local regional changes, global theories propose that awareness emerges from the propagation of neural signals across a broad extent of sensory and association cortex. Here we tested the scalar extent of brain changes associated with awareness using graph theoretical analysis applied to functional connectivity data acquired at ultra-high field while subjects performed a simple masked target detection task. We found that awareness of a visual target is associated with a degradation of the modularity of the brain's functional networks brought about by an increase in intermodular functional connectivity. These results provide compelling evidence that awareness is associated with truly global changes in the brain's functional connectivity.

Keywords: awareness; consciousness; functional connectivity; graph theory.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Algorithms
  • Awareness*
  • Behavior
  • Brain Mapping / methods*
  • Consciousness
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Models, Neurological
  • Models, Statistical
  • Nerve Net*
  • Young Adult