title: Global motion perception in children with amblyopia as a function of spatial and temporal stimulus parameters.
abstract: Global motion sensitivity in typically developing children depends on the spatial (Δx) and temporal (Δt) displacement parameters of the motion stimulus. Specifically, sensitivity for small Δx values matures at a later age, suggesting it may be the most vulnerable to damage by amblyopia. To explore this possibility, we compared motion coherence thresholds of children with amblyopia (7-14years old) to age-matched controls. Three Δx values were used with two Δt values, yielding six conditions covering a range of speeds (0.3-30deg/s). We predicted children with amblyopia would show normal coherence thresholds for the same parameters on which 5-year-olds previously demonstrated mature performance, and elevated coherence thresholds for parameters on which 5-year-olds demonstrated immaturities. Consistent with this, we found that children with amblyopia showed deficits with amblyopic eye viewing compared to controls for small and medium Δx values, regardless of Δt value. The fellow eye showed similar results at the smaller Δt. These results confirm that global motion perception in children with amblyopia is particularly deficient at the finer spatial scales that typically mature later in development. An additional implication is that carefully designed stimuli that are adequately sensitive must be used to assess global motion function in developmental disorders. Stimulus parameters for which performance matures early in life may not reveal global motion perception deficits.
authors.affiliation: Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC V6T 1Z4, Canada. Electronic address: kmeier@psych.ubc.ca.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Meier
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Rm E300E, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Sum
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Rm E300E, 4480 Oak Street, Vancouver, BC V6H 3V4, Canada. Electronic address: giaschi@mail.ubc.ca.
authors.forename: Deborah
authors.initials: D
authors.lastname: Giaschi
mesh_terms: D000293:Adolescent; D000550:Amblyopia / Q000503:physiopathology*; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002657:Child Development / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*
keywords: Amblyopia; Global motion perception; Psychophysics; Visual development