title: The Effects of Chronic Right Hemispheric Damage on the Allocation of Spatial Attention: Alterations of Accuracy and Reliability.
abstract: Right hemispheric damage (RHD) caused by strokes often induce attentional disorders such as hemispatial neglect. Most patients with neglect over time have a reduction in their ipsilesional spatial attentional bias. Despite this improvement in spatial bias, many patients remain disabled. The cause of this chronic disability is not fully known, but even in the absence of a directional spatial attentional bias, patients with RHD may have an impaired ability to accurately and precisely allocate their spatial attention. This inaccuracy and variable directional allocation of spatial attention may be revealed by repeated performance on a spatial attentional task, such as line bisection (LBT). Participants with strokes of their right versus left (LHD) hemisphere along with healthy controls (HC) performed 24 consecutive trials of 24 cm horizontal line bisections. A vector analysis of the magnitude and direction of deviations from midline, as well as their standard deviations (SD), were calculated. The results demonstrated no significant difference between the LHD, RHD and HC groups in overall spatial bias (mean bisection including magnitude and direction); however, the RHD group had a significantly larger variability of their spatial errors (SD), and made larger errors (from midline) than did the LHD and HC groups. There was a curvilinear relationship between the RHD participants' performance variability and their severity of their inaccuracy. Therefore, when compared to HC and LHD, the RHD subjects' performance on the LBT is more variable and inaccurate.
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Glen R
authors.initials: GR
authors.lastname: Finney
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Williamson
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: D
authors.initials: D
authors.lastname: Brandon Burtis
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Valeria
authors.initials: V
authors.lastname: Drago
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Mizuno
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Jeong
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Crucian
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Salsabil
authors.initials: S
authors.lastname: Haque
authors.affiliation: 1Department of Neurology and Center for Neuropsychological Studies,Department of Veteran Affairs Medical Center,University of Florida College of Medicine,and Neurology Service. Gainesville,Florida,USA.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Heilman
mesh_terms: D000328:Adult; D000368:Aged; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000209:etiology*; D001925:Brain Damage, Chronic / Q000150:complications*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013028:Space Perception / Q000502:physiology*
keywords: Impersistence; Inattention; Line bisection; Neglect; Stroke; Variability