title: Motion processing deficits in migraine are related to contrast sensitivity.
abstract: BACKGROUND
  There are conflicting reports concerning the ability of people with migraine to detect and discriminate visual motion. Previous studies used different displays and none adequately assessed other parameters that could affect performance, such as those that could indicate precortical dysfunction.
  
  
  METHODS
  Motion-direction detection, discrimination and relative motion thresholds were compared from participants with and without migraine. Potentially relevant visual covariates were included (contrast sensitivity; acuity; stereopsis; visual discomfort, stress, triggers; dyslexia).
  
  
  RESULTS
  For each task, migraine participants were less accurate than a control group and had impaired contrast sensitivity, greater visual discomfort, visual stress and visual triggers. Only contrast sensitivity correlated with performance on each motion task; it also mediated performance.
  
  
  CONCLUSIONS
  Impaired performance on certain motion tasks can be attributed to impaired contrast sensitivity early in the visual system rather than a deficit in cortical motion processing per se. There were, however, additional differences for global and relative motion thresholds embedded in noise, suggesting changes in extrastriate cortex in migraine. Tasks to study the effects of noise on performance at different levels of the visual system and across modalities are recommended. A battery of standard visual tests should be included in any future work on the visual system and migraine.
authors.affiliation: Department of Psychological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK. a.shepherd@bbk.ac.uk
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Shepherd
authors.forename: Heidi M
authors.initials: HM
authors.lastname: Beaumont
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Hine
mesh_terms: D000293:Adolescent; D000328:Adult; D016477:Artifacts; D015350:Contrast Sensitivity / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D004410:Dyslexia / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000150:complications / Q000503:physiopathology*; D009039:Motion Perception / Q000502:physiology*; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology*; D055815:Young Adult