title: Structural and functional correlates of visual field asymmetry in the human brain by diffusion kurtosis MRI and functional MRI.
abstract: Human visual performance has been observed to show superiority in localized regions of the visual field across many classes of stimuli. However, the underlying neural mechanisms remain unclear. This study aims to determine whether the visual information processing in the human brain is dependent on the location of stimuli in the visual field and the corresponding neuroarchitecture using blood-oxygenation-level-dependent functional MRI (fMRI) and diffusion kurtosis MRI, respectively, in 15 healthy individuals at 3 T. In fMRI, visual stimulation to the lower hemifield showed stronger brain responses and larger brain activation volumes than the upper hemifield, indicative of the differential sensitivity of the human brain across the visual field. In diffusion kurtosis MRI, the brain regions mapping to the lower visual field showed higher mean kurtosis, but not fractional anisotropy or mean diffusivity compared with the upper visual field. These results suggested the different distributions of microstructural organization across visual field brain representations. There was also a strong positive relationship between diffusion kurtosis and fMRI responses in the lower field brain representations. In summary, this study suggested the structural and functional brain involvements in the asymmetry of visual field responses in humans, and is important to the neurophysiological and psychological understanding of human visual information processing.
authors.affiliation: aUPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine bDepartment of Bioengineering, Swanson School of Engineering cNeuroImaging Laboratory, University of Pittsburgh dLouis J. Fox Center for Vision Restoration eMcGowan Institute for Regenerative Medicine, University of Pittsburgh and UPMC fCenter for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, Pennsylvania, USA gDepartment of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Caitlin
authors.initials: C
authors.lastname: O'Connell
authors.forename: Leon C
authors.initials: LC
authors.lastname: Ho
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Murphy
authors.forename: Ian P
authors.initials: IP
authors.lastname: Conner
authors.forename: Gadi
authors.initials: G
authors.lastname: Wollstein
authors.forename: Rakie
authors.initials: R
authors.lastname: Cham
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Chan
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D013223:Statistics as Topic; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen