title: Monocular patching may induce ipsilateral "where" spatial bias.
abstract: Spatial bias is an asymmetry of perception and/or representation of spatial information - "where" bias -, or of spatially directed actions - "aiming" bias. A monocular patch may induce contralateral "where" spatial bias (the Sprague effect [Sprague, J. M. (1966). Interaction of cortex and superior colliculus in mediation of visually guided behavior in cat. Science, 153(3743), 1544-1547]). However, an ipsilateral patch-induced spatial bias may be observed if visual occlusion results in top-down, compensatory re-allocation of spatial perceptual or representational resources toward the region of visual deprivation. Tactile distraction from a monocular patch may also contribute to an ipsilateral bias. To examine these hypotheses, neurologically normal adults bisected horizontal lines at baseline without a patch, while wearing a monocular patch, and while wearing tactile-only and visual-only monocular occlusion. We fractionated "where" and "aiming" spatial bias components using a video apparatus to reverse visual feedback for half of the test trials. The results support monocular patch-induced ipsilateral "where" spatial errors, which are not consistent with the Sprague effect. Further, the present findings suggested that the induced ipsilateral bias may be primarily induced by visual deprivation, consistent with compensatory "where" resource re-allocation.
authors.affiliation: Stroke Rehabilitation Research Laboratory, the Kessler Foundation Research Center, The University of Medicine and Dentistry, NJ - NJ Medical School (UMDNJ-NJMS), West Orange, NJ 07052, United States. pchen@kessler.foundation.de
authors.forename: Peii
authors.initials: P
authors.lastname: Chen
authors.forename: Lillian
authors.initials: L
authors.lastname: Erdahl
authors.forename: Anna M
authors.initials: AM
authors.lastname: Barrett
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013477:Superior Colliculi / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*; D014795:Visual Pathways / Q000033:anatomy & histology / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult