title: Vertical bias in neglect: a question of time?
abstract: Neglect is defined as the failure to attend and to orient to the contralesional side of space. A horizontal bias towards the right visual field is a classical finding in patients who suffered from a right-hemispheric stroke. The vertical dimension of spatial attention orienting has only sparsely been investigated so far. The aim of this study was to investigate the specificity of this vertical bias by means of a search task, which taps a more pronounced top-down attentional component. Eye movements and behavioural search performance were measured in thirteen patients with left-sided neglect after right hemispheric stroke and in thirteen age-matched controls. Concerning behavioural performance, patients found significantly less targets than healthy controls in both the upper and lower left quadrant. However, when targets were located in the lower left quadrant, patients needed more visual fixations (and therefore longer search time) to find them, suggesting a time-dependent vertical bias.
authors.affiliation: Perception and Eye Movement Laboratory, Department of Neurology, Bern University Hospital Inselspital, and University of Bern, Freiburgstrasse 10, 3010 Bern, Switzerland.
authors.forename: Dario
authors.initials: D
authors.lastname: Cazzoli
authors.forename: Thomas
authors.initials: T
authors.lastname: Nyffeler
authors.forename: Christian W
authors.initials: CW
authors.lastname: Hess
authors.forename: René M
authors.initials: RM
authors.lastname: Müri
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D004192:Discrimination, Psychological / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000503:physiopathology*; D010775:Photic Stimulation; D012016:Reference Values; D017603:Signal Detection, Psychological; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors; D014794:Visual Fields / Q000502:physiology*