The imbalance of oculomotor capture in unilateral visual neglect.
Visual neglect has been associated with an imbalance in the level of activity in the saccadic system: activity in the contralesional field is suppressed, which makes target selection unlikely. We recorded eye movements of a patient with hemispatial neglect and a group of healthy participants during an oculomotor distractor paradigm. Results showed that the interfering effects of a distractor were very strong when presented in her ipsilesional visual field. However, when the distractor was presented in her contralesional field, there were no interfering effects when the target was presented in her ipsilesional field. These findings could not be explained by the presence of a visual field defect as revealed by the results of two hemianopic patients. Our results are in line with an imbalance in the level of activity in the saccadic system in visual neglect because visual elements presented in the contralesional field did not compete for saccadic selection.
Van der Stigchel
Stefan
S
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands. S.VanderStigchel@uu.nl
Nijboer
Tanja C W
TC
D000368:Aged; D001288:Attention / Q000502:physiology*; D004215:Distance Perception / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular; D007839:Functional Laterality / Q000502:physiology*; D006423:Hemianopsia / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015835:Ocular Motility Disorders / Q000175:diagnosis* / Q000503:physiopathology; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000503:physiopathology; D010775:Photic Stimulation; D012438:Saccades / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*