title: The contribution of stimulus-driven and goal-driven mechanisms to feature-based selection in patients with spatial attention deficits.
abstract: When people search a display for a target defined by a unique feature, fast saccades are predominantly stimulus-driven whereas slower saccades are primarily goal-driven. Here we use this dissociative pattern to assess whether feature-based selection in patients with lateralized spatial attention deficits is impaired in stimulus-driven processing, goal-driven processing, or both. A group of patients suffering from extinction or neglect after parietal damage, and a group of healthy, age-matched controls, were instructed to make a saccade to a uniquely oriented target line which was presented simultaneously with a differently oriented distractor line. We systematically varied the salience of the target and distractor by changing the orientation of background elements, and used a time-based model to extract stimulus-driven (salience) and goal-driven (target set) components of selection. The results show that the patients exhibited reduced stimulus-driven processing only in the contralesional hemifield, while goal-driven processing was reduced across both hemifields.
authors.affiliation: Department of Cognitive Psychology, VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Isabel
authors.initials: I
authors.lastname: Dombrowe
authors.forename: Mieke
authors.initials: M
authors.lastname: Donk
authors.forename: Hayley
authors.initials: H
authors.lastname: Wright
authors.forename: Christian N L
authors.initials: CN
authors.lastname: Olivers
authors.forename: Glyn W
authors.initials: GW
authors.lastname: Humphreys
mesh_terms: D016022:Case-Control Studies; D006040:Goals; D006801:Humans; D010468:Perceptual Disorders / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*