title: Perception of motion transparency in 5-month-old infants.
abstract: We investigated the perceptual development of motion transparency in 3- to 5-month-old infants. In two experiments we tested a total of 55 infants and examined their preferential looking behaviour. In experiment 1, we presented transparent motion as a target, and uniform motion as a non-target consisting of random-dot motions. We measured the time during which infants looked at the target and non-target stimuli. In experiment 2, we used paired-dot motions (Qian et al, 1994 Journal of Neuroscience 14 7357-7366) as non-targets and also measured target looking time. We calculated the ratio of the target looking time to the total target and no-target looking time. In both experiments we controlled the dot size, speed, the horizontal travel distance of the dots, and the motion pattern of the dots. The results demonstrated that 5-month-old infants showed a statistically significant preference for motion transparency in almost all stimulus conditions, whereas the preference in 3- and 4-month-old infants depended on stimulus conditions. These results suggest that the sensitivity to motion transparency was robust in 5-month-olds, but not in 3- and 4-month-olds.
authors.affiliation: Department of Psychology, Shukutoku University, Daiganji 200, Chuo-ku, Chiba City, 260-8701, Japan. kanazawa@soc.shukutoku.ac.jp
authors.forename: So
authors.initials: S
authors.lastname: Kanazawa
authors.forename: Nobu
authors.initials: N
authors.lastname: Shirai
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Otsuka
authors.forename: Masami K
authors.initials: MK
authors.lastname: Yamaguchi
mesh_terms: D000375:Aging / Q000523:psychology; D002657:Child Development / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology; D005364:Field Dependence-Independence; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000502:physiology; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics