Amodal completion in infants: Straight continuity versus symmetry1

A visual pattern's orientation influences how adults amodally complete that pattern. We examined whether this is also the case with infants using Markovich's pattern, consisting of a black polygon partially occluded by a gray disc, which is completed as either a vertically symmetrical hexagon or as a pentagon, depending on the pattern's orientation. Our experiment consisted of two prefamiliarization test trials, six familiarization trials, and two postfamiliarization test trials. In the familiarization trials, two identical Markovich patterns, upright or slanted, were presented to 7–8‐month‐old infants (N = 28) side by side on a CRT monitor. In the pre‐ and postfamiliarization test trials, a pentagon and a hexagon were presented side by side. Infants looked longer at the hexagon than at the pentagon in the postfamiliarization test trials. This suggests that infants completed the pattern as a pentagon regardless of the pattern's orientation. This lack of an orientation effect suggests that infants do not use the figure's symmetry as a guiding principle for amodal completion.     

Infants' perception of human body orientation and the effect of a surrounding square

We examined two hypotheses about infants' perception of orientation. The first is that infants develop an expectation that the human body is normally vertical. To examine this hypothesis, we compared the preferential looking to vertical and oblique versions of a silhouette of a human body, to an inverted body, and to a grating. Our second hypothesis is that presenting a figure inside a frame affects the perception of orientation. To examine the second hypothesis, we placed the figure inside a surrounding square that was oriented normally or at an oblique angle. Four‐ to seven‐month‐old infants (N = 78) participated. The results showed that 6–7‐month‐old infants preferred the oblique human body presented upright; no such preference was observed for the inverted body or the grating. For all types of displays, the surrounding square influenced preferences. Our results suggest that (a) 6–7‐month‐old infants have specific expectations about the orientation of the human body, and (b) surrounding displays with a square could influence the perception of the orientation of the human body, as well as that of a grating.     

Perception of the Ebbinghaus illusion in 5- to 8-month-old infants

The Ebbinghaus illusion is a geometric illusion based on a size-contrast between a central circle and surrounding circles. A central circle surrounded by small inducing circles is perceived as being larger than a central circle surrounded by large inducing circles. In the present study we investigated 5- to 8-month-old infants' perception of the Ebbinghaus illusion using a preferential-looking paradigm. We measured the preference between a central circle surrounded by small inducing circles (overestimated figure) and a central circle surrounded by large inducing circles (underestimated figure). Infants showed a significant preference for the overestimated figure when the central circle was flashing, but not when it was static. Furthermore, there was no preference between the two figures when the central circles were removed. These results suggest that infants' preference reflects their perception of the size illusion of the central circle. There is a possibility that 5- to 8-month-old infants perceive the Ebbinghaus illusion.     

Learning unfamiliar faces in infants: The advantage of the regular sequence presentation and the three‐quarter view superiority

We investigated the effect of the regular sequence of different views and the three‐quarter view effect on the learning of unfamiliar faces by infants. 3–8‐month‐old infants were familiarized with unfamiliar female faces in either the regular condition (presenting 11 different face views from the frontal view to the left‐side profile view in regular order) or the random condition (presenting the same 11 different face views in random order). Following the familiarization, infants were tested with a pair of a familiarized and a novel female face either in a three‐quarter (Experiment 1) or in a profile view (Experiment 2). Results showed that only 6–8‐month‐old infants could identify a familiarized face in the regular condition when they were tested in three‐quarter views. In contrast, 6–8‐month‐old infants showed no significant novelty preference in profile views. The results suggest that the regular sequence of different face views promotes the learning of unfamiliar faces by infants over 6 months old. Moreover, our findings imply that the three‐quarter view effect appears in infants.     

Young infants’ sensitivity to shading stimuli with radial motion1

Abstract: The purpose of this study was to examine 5‐month‐old infant's sensitivity to a shading cue with radial motion. Our stimuli were radially expanding or contracting circles with vertical or horizontal shadings. We tested infants’ preference for vertical (top‐ and bottom‐lit) and horizontal (left‐ and right‐lit) shadings. The results indicate that infants tested with the vertical shading showed significant preference for the top‐lit shading, whereas infants tested with the horizontal shading did not show any significant preference. The fact that the significant preference was observed only in the vertical shading condition suggests that 5‐month‐old infants might use shading information on the basis of the “light‐from‐above assumption.” We revealed that even 5‐month‐old infants are sensitive to shading information when they are exposed to shading stimuli with radial motion.     

When openness to experience and conscientiousness affect continuous learning: A mediating role of intrinsic motivation and a moderating role of occupation1

Research on the effects of personality on work behaviors has adopted either the motivational meditation perspective or the person‐situation interaction perspective. This study attempted to integrate both of the perspectives in a single causal model. Specifically, using data collected from systems engineers and car salespeople in Japan, we investigated the mediating role of intrinsic motivation in the links from openness and conscientiousness to continuous learning, and the moderating role of occupation on the mediation mechanism. The results indicated that, for systems engineers, the effects of those personality traits on continuous learning were completely mediated via intrinsic motivation. For car salespeople, however, the trait effects on the outcome variable are direct, rather than transmitted through intrinsic motivation. The meanings of the findings and directions for future research are discussed.