Foveal versus parafoveal scanpaths of visual imagery in virtual hemianopic subjects.
Sophisticated string analysis [compressed regional string analysis, cRSE] shows significant differences following therapeutical masking of the foveal region during a virtual hemianopia. The visual imagery scanpath is done over a compressed mental image that needs longer fixation duration but fewer saccades than the real image. Combination of different viewing tasks with types of pictures permits to show how scanpath top-down strategies can be enforced or decreased by proper combination of task and picture; this is influenced by the mask of fovea versus no-mask of fovea difference, with bottom up mechanisms becoming more important with loss of foveal viewing strategies in the mask condition.
Zangemeister
Wolfgang H
WH
Department of Neurology, Clinical Neuroscience Unit, University Hamburg, Germany. WHIZ@uke.uni-hamburg.de
Liman
Thomas
T
D003201:Computers; D003627:Data Interpretation, Statistical; D005584:Fovea Centralis / Q000503:physiopathology; D006423:Hemianopsia / Q000503:physiopathology*; D006801:Humans; D008390:Markov Chains; D008954:Models, Biological; D010470:Perceptual Masking / Q000502:physiology; D010775:Photic Stimulation; D012438:Saccades / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology