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Kimberly Meier, Brian Sum, Deborah Giaschi; Global motion perception deficits in children with amblyopia as a function of spatial and temporal stimulus parameters. Journal of Vision 2015;15(12):653. doi: https://doi.org/10.1167/15.12.653.
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© ARVO (1962-2015); The Authors (2016-present)
Introduction: There are conflicting results on whether children with amblyopia have deficits in global motion perception. Differences in the stimulus parameters used in different studies may have led to these discrepancies. Specifically, the speed of a global motion stimulus can be broken down into a ratio of spatial (∆x) and temporal (∆t) displacement parameters. We have shown that coherence thresholds for global motion direction discrimination are immature in 4-6 year olds when smaller ∆x/∆t values are used to create the speed, but adult-like when larger values are used (Meier & Giaschi, 2014). We hypothesize that coherence thresholds in children with amblyopia will be elevated for parameters that take longer to mature, and similar to controls for parameters that mature earlier. Methods: Coherence thresholds were assessed in children with amblyopia (7-16 years, M = 11.21) and age-matched controls using a two-alternative forced choice direction discrimination task. Six combinations of spatial and temporal parameters were used: spatial displacement (∆x) was 1, 5, or 30 arc min; temporal displacement (∆t) was 17 or 50 ms. Children were assessed monocularly, and conducted one run per eye, for a total of 12 measurements. Results: Children with amblyopia had elevated coherence thresholds in the amblyopic eye for ∆x = 1 and 5 arc min, but not ∆x = 30 arc min, at both ∆t = 17 and 50 ms. There was a similar trend in the fellow eye at ∆t = 17 ms, ∆x = 1 arc min. Conclusion: Children with amblyopia show deficits in global motion perception in each eye when they are tested with stimuli that use shorter spatial displacements, regardless of temporal displacement. This is consistent with the hypothesis that aspects of motion perception that take longer to mature are more susceptible to damage by amblyopia.
Meeting abstract presented at VSS 2015
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