Perception of occlusion by young infants: Must the occlusion event be congruent with the occluder?

• Published in: Infant behavior & development Vol. 44; pp. 240 - 248
• Main Authors: Bremner, J. Gavin, Slater, Alan M., Mason, Uschi C., Spring, Jo, Johnson, Scott P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2016
• Subjects: Accretion; Cues; Deletion; Form Perception - physiology; Humans; Illusions - physiology; Infant; Infant Behavior - physiology; Male; Motion Perception - physiology; Occlusion; Photic Stimulation; Reaction Time; Trajectory continuity; Occlusion; Deletion; Trajectory continuity; Accretion
• ISSN: 0163-6383; 1879-0453; 1934-8800
• DOI: 10.1016/j.infbeh.2016.07.007

•The work reported is a systematic investigation of the effects of dislocating different cues to occlusion on young infants' perception of trajectory continuity. The results provide clear evidence that accretion and deletion must happen congruently with visible luminance-defined edges. As such, this work contributes further to our understanding of young infants' perception of occlusion events and the conditions under which they perceive object persistence across occlusion. This in turn contributes to our understanding of the perceptual bases of object permanence. Four-month-old infants perceive continuity of an object’s trajectory through occlusion, even when the occluder is illusory, and several cues are apparently needed for young infants to perceive a veridical occlusion event. In this paper we investigated the effects of dislocating the spatial relation between the occlusion events and the visible edges of the occluder. In two experiments testing 60 participants, we demonstrated that 4-month-olds do not perceive continuity of an object’s trajectory across an occlusion if the deletion and accretion events are spatially displaced relative to the occluder edges (Experiment 1) or if deletion and accretion occur along a linear boundary that is incorrectly oriented relative to the occluder’s edges (Experiment 2). Thus congruence of these cues is apparently important for perception of veridical occlusion. These results are discussed in relation to an account of the development of perception of occlusion and object persistence.