title: Directional motion sensitivity under transparent motion conditions.
abstract: We measured directional sensitivity to a foreground pattern while an orthogonally directed background pattern was present under transparent motion conditions. For both foreground and background pattern, the speed was varied between 0.5 and 28 deg sec-1. A multi-step paradigm was employed which results in a better estimation of the suppressive or facilitatory effects than previously applied single-step methods (e.g. measuring Dmax or Dmin). Moreover, our method gives insight into the interactions for a wide range of speed and not just the extreme motion thresholds (the D-values). We found that high background speeds have an inhibitory effect on the detection of a range of high foreground speeds and low background speeds have an inhibitory effect on a range of low foreground speeds. Intermediate background pattern speeds inhibit the detection of both low and high foreground pattern speeds and do so in a systemic manner.
authors.affiliation: Vision Sciences Laboratory, Harvard University, Cambridge, MA 02138, USA. frans@wjh.harvard.edu
authors.forename: F A
authors.initials: FA
authors.lastname: Verstraten
authors.forename: R E
authors.initials: RE
authors.lastname: Fredericksen
authors.forename: R J
authors.initials: RJ
authors.lastname: van Wezel
authors.forename: J C
authors.initials: JC
authors.lastname: Boulton
authors.forename: W A
authors.initials: WA
authors.lastname: van de Grind
mesh_terms: D003867:Depth Perception / Q000502:physiology; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D013997:Time Factors