title: An independent effect of spatial frequency on motion integration reveals orientation resolution.
abstract: OBJECTIVE
  To investigate the independent role of spatial frequency on component motion integration.
  
  
  METHODS
  Two Type II plaids were presented at varying spatial frequencies. The velocity vectors of the underlying components were constructed so that predicted speed and direction from the components; the Intersection of Constraints; the vector average; and distortion products, remained constant for each of the two plaids across spatial frequency. Perceived direction was measured using a method of adjustment.
  
  
  RESULTS
  Perceived direction changed as a function of spatial frequency, approaching the pattern direction only at spatial frequencies greater than 0.5cpd.
  
  
  CONCLUSIONS
  Spatial frequency has an independent effect on the component integration stage that determines perceived pattern motion direction. The results appear to reflect the resolution of orientation for recombination of the components at low spatial frequencies. These results have implications for motion modelling and possible clinical applications.
authors.affiliation: School of Psychology, University of Nottingham, University Park, Nottingham NG7 2RD, UK. l.bowns@psychology.nottingham.ac.uk
authors.forename: Linda
authors.initials: L
authors.lastname: Bowns
authors.forename: Alexander J S
authors.initials: AJ
authors.lastname: Beckett
mesh_terms: D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation / Q000379:methods