title: Global motion perception is independent from contrast sensitivity for coherent motion direction discrimination and visual acuity in 4.5-year-old children.
abstract: Global motion processing depends on a network of brain regions that includes extrastriate area V5 in the dorsal visual stream. For this reason, psychophysical measures of global motion perception have been used to provide a behavioral measure of dorsal stream function. This approach assumes that global motion is relatively independent of visual functions that arise earlier in the visual processing hierarchy such as contrast sensitivity and visual acuity. We tested this assumption by assessing the relationships between global motion perception, contrast sensitivity for coherent motion direction discrimination (henceforth referred to as contrast sensitivity) and habitual visual acuity in a large group of 4.5-year-old children (n=117). The children were born at risk of abnormal neurodevelopment because of prenatal drug exposure or risk factors for neonatal hypoglycemia. Motion coherence thresholds, a measure of global motion perception, were assessed using random dot kinematograms. The contrast of the stimuli was fixed at 100% and coherence was varied. Contrast sensitivity was measured using the same stimuli by fixing motion coherence at 100% and varying dot contrast. Stereoacuity was also measured. Motion coherence thresholds were not correlated with contrast sensitivity or visual acuity. However, lower (better) motion coherence thresholds were correlated with finer stereoacuity (ρ=0.38, p=0.004). Contrast sensitivity and visual acuity were also correlated (ρ=-0.26, p=0.004) with each other. These results indicate that global motion perception for high contrast stimuli is independent of contrast sensitivity and visual acuity and can be used to assess motion integration mechanisms in children.
authors: School of Optometry and Vision Science, University of Auckland, New Zealand.
authors: Arijit
authors: A
authors: Chakraborty
authors: School of Optometry and Vision Science, University of Auckland, New Zealand.
authors: Nicola S
authors: NS
authors: Anstice
authors: School of Optometry and Vision Science, University of Auckland, New Zealand.
authors: Robert J
authors: RJ
authors: Jacobs
authors: School of Optometry and Vision Science, University of Auckland, New Zealand.
authors: Nabin
authors: N
authors: Paudel
authors: Brown Center for the Study of Children at Risk, Warren Alpert Medical School at Brown University, USA.
authors: Linda L
authors: LL
authors: LaGasse
authors: Brown Center for the Study of Children at Risk, Warren Alpert Medical School at Brown University, USA.
authors: Barry M
authors: BM
authors: Lester
authors: Department of Psychological Medicine, University of Auckland, New Zealand.
authors: Trecia A
authors: TA
authors: Wouldes
authors: Liggins Institute, University of Auckland, New Zealand.
authors: Jane E
authors: JE
authors: Harding
authors: School of Optometry and Vision Science, University of Auckland, New Zealand; School of Optometry and Vision Science, University of Waterloo, Canada. Electronic address: ben.thompson@uwaterloo.ca.
authors: Benjamin
authors: B
authors: Thompson
mesh_terms: D000704:Analysis of Variance; D002675:Child, Preschool; D015350:Contrast Sensitivity / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology; D005133:Eye Movements; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*
keywords: At risk infant; Extrastriate visual cortex; Preschool vision assessment; Visual development