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

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Dentico, Daniela; Cheung, Bing Leung; Chang, Jui-Yang; Guokas, Jeffrey; Boly, Melanie; Tononi, Giulio; Van Veen, Barry
Year of Publication: 2014
Journal: Neuroimage
Volume: 100
Pagination: 237-43
Date Published: 2014 Oct 15
Publication Language: eng
ISSN: 1095-9572
Keywords: Adult, Brain Mapping, Cerebral Cortex, Electroencephalography, Female, Humans, Imagination, Male, Models, Statistical, Visual perception, Young Adult

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.

DOI: 10.1016/j.neuroimage.2014.05.081
Alternate Journal: Neuroimage