Reversal of cortical information flow during visual imagery as compared to visual perception

Neuroimage. 2014 Oct 15:100:237-43. doi: 10.1016/j.neuroimage.2014.05.081. Epub 2014 Jun 6.

Abstract

The role of bottom-up and top-down connections during visual perception and the formation of mental images was examined by analyzing high-density EEG recordings of brain activity using two state-of-the-art methods for assessing the directionality of cortical signal flow: state-space Granger causality and dynamic causal modeling. We quantified the directionality of signal flow in an occipito-parieto-frontal cortical network during perception of movie clips versus mental replay of the movies and free visual imagery. Both Granger causality and dynamic causal modeling analyses revealed an increased top-down signal flow in parieto-occipital cortices during mental imagery as compared to visual perception. These results are the first direct demonstration of a reversal of the predominant direction of cortical signal flow during mental imagery as compared to perception.

Keywords: Bottom-up; Dynamic causal modeling; Granger causality; Imagery; Perception; Top-down.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping / methods*
  • Cerebral Cortex / physiology*
  • Electroencephalography / methods*
  • Female
  • Humans
  • Imagination / physiology*
  • Male
  • Models, Statistical
  • Visual Perception / physiology*
  • Young Adult