title: Infants' sensitivity to shading and line junctions.
abstract: We examined the sensitivity to shading and line junction cues in human infants aged 5-8 months using computer-generated displays containing a rectangular-wave grating and a serrated aperture. In Experiment 1, infants were presented with a pair of displays: a two-dimensional to three-dimensional (2D-3D) display, alternating between 2D and 3D images, and a 2D-2D display, alternating between two 2D images. The 3D image consisted of black-and-white borders aligned with the peaks of a serrated aperture, creating the appearance of a 3D folded surface. The 2D image consisted of the black-and-white borders misaligned with the peaks of a serrated aperture, which does not create a 3D impression for adults. Seven- and 8-month-old infants looked longer at the 2D-3D display than the 2D-2D display. In contrast, 5- and 6-month-old infants did not exhibit a looking preference. In Experiment 2, we used images with double-cycle rectangular-wave gratings to impair shading information. These images consisted of black-and-white borders aligned with half of the peaks and misaligned with latter half of the peaks of a serrated aperture, giving the appearance of surface markings. Seven- and 8-month-old infants did not exhibit a significant difference in preference between the two test displays. These results could not be explained by the young infant's failure of discrimination due to the experimental procedure (Experiment 3). These results showed that the sensitivity to shading and line junctions change between 5-6 and 7-8 months of age.
authors.affiliation: Section of Language and Intelligence, Primate Research Institute, Kyoto University, 41-2 Inuyama, Aichi 484-8506, Japan. imura@pri.kyoto-u.ac.jp <imura@pri.kyoto-u.ac.jp>
authors.forename: Tomoko
authors.initials: T
authors.lastname: Imura
authors.forename: Masami K
authors.initials: MK
authors.lastname: Yamaguchi
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: Masaki
authors.initials: M
authors.lastname: Tomonaga
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yagi
mesh_terms: D002657:Child Development / Q000502:physiology*; D003196:Computer Graphics; D015350:Contrast Sensitivity / Q000502:physiology; D003463:Cues; D003867:Depth Perception / Q000502:physiology; D004192:Discrimination, Psychological; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D007223:Infant; D008297:Male; D011601:Psychophysics; D015203:Reproducibility of Results; D014796:Visual Perception / Q000502:physiology*