title: Anisotropic motion coherence sensitivities to expansion/contraction motion in early infancy.
abstract: We investigated 2- and 3-month-olds' motion coherence sensitivities to radial expansion/contraction by using the preferential looking method. The infants were tested with a stimulus composed of two dynamic random dot patterns placed side by side: an expansion (or a contraction) pattern and a random directional pattern. The results showed that the 3-month-old infants tested with both a contraction and random directional pattern could discriminate between those two motions significantly, even when the contraction motion coherence was relatively low (50%). On the other hand, the 3-month-old infants who were tested with both expansion and random directional pattern could not discriminate between those two motions. None of the 2-month-old infants showed significant discrimination between the expansion/contraction and random motion patterns. Results of the present study suggest that anisotropic motion coherence sensitivities to radial expansion/contraction emerge at around 3 months of age.
authors.affiliation: Department of Psychology, Graduate School of Literature, Chuo University, 742-1, Higashinakano, Hachioji-city, Tokyo 192-0393, Japan. o2341006@crow.grad.tamacc.chuo-u.ac.jp
authors.forename: Nobu
authors.initials: N
authors.lastname: Shirai
authors.forename: So
authors.initials: S
authors.lastname: Kanazawa
authors.forename: Masami K
authors.initials: MK
authors.lastname: Yamaguchi
mesh_terms: D002657:Child Development; D004192:Discrimination, Psychological / Q000502:physiology*; D006801:Humans; D007223:Infant; D009043:Motor Activity / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010364:Pattern Recognition, Visual