title: Masks reveal processing time for alignment across space.
abstract: Does spatial separation incur a processing time requirement before precise alignment judgements can occur? Alignment thresholds for separated lines are measured for exposure durations from 27 to 500ms, with and without post-masks. The effect of masks on visibility is controlled. Unlike without a post-mask, with an effective post-mask, alignment thresholds improve substantially with time, i.e. in square-root fashion. Alignment across space may be important for further shape analysis. Threshold improvement is probably not explained by a spatial scale shift of visual analysis over time. A higher-order collection stage appears to refine relative position information for up to 200ms.
authors.affiliation: Anglia Vision Research, Anglia Ruskin University, Cambridge CB1 1PT, UK. s.j.waugh@anglia.ac.uk
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Waugh
mesh_terms: D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D009949:Orientation; D010470:Perceptual Masking / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D012684:Sensory Thresholds / Q000502:physiology; D013028:Space Perception / Q000502:physiology*