title: The maturation of global motion perception depends on the spatial and temporal offsets of the stimulus.
abstract: The typical development of motion perception is commonly assessed with tests of global motion integration using random dot kinematograms. There are discrepancies, however, with respect to when typically-developing children reach adult-like performance on this task, ranging from as early as 3 years to as late as 12 years. To address these discrepancies, the current study measured the effect of frame duration (Δt) and signal dot spatial offset (Δx) on motion coherence thresholds in adults and children. Two Δt values were used in combination with seven Δx values, for a range of speeds (0.3-38 deg/s). Developmental comparisons showed that for the longer Δt, children performed as well as adults for larger Δx, and were immature for smaller Δx. When parameters were expressed as speed, there was a range of intermediate speeds (4-12 deg/s) for which maturity was dependent on the values of Δx and Δt tested. These results resolve previous discrepancies by showing that motion sensitivity to a given speed may be mature, or not, depending on the underlying spatial and temporal properties of the motion stimulus.
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 A146, 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; D000328:Adult; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D055815:Young Adult
keywords: Global motion perception; Psychophysics; Random dot kinematograms; Visual development