Development of systematic object viewpoint selection during active object manipulation from late infancy to early childhood
This dissertation is concerned with the object views children present to themselves in the context of a privileged form of generating visual experiences - the manual exploration of objects. Four studies investigated children's object viewpoint selection, from late infancy to early childhood, using a novel method – a head mounted camera – that records an approximation of the child's visual field while she manipulates an object. These are the first studies of this type. In a cross-sectional study, children aged 12 to 36 months were asked to inspect one object at a time from a set of known and novel objects. The results show a gradual preference with age, systematic from early on, towards object orientations that show only one side of the object, so called planar views (principal axis either perpendicular or parallel to line of sight); a pattern of active object inspection found in previous adult studies and implicated in more efficient visual learning of objects. In another study, children played with a new set of novel objects and were tested in a preferential looking task immediately after. The results show a preference to look at the objects’ planar views but only for those children that actively manipulated the objects previously. The bias towards this specific type of viewpoint seems to be stable over short periods of time and not related to object familiarity; a result suggested by a 4-week longitudinal study in children aged 18 to 24. A final study examined the distribution of inspection time across all viewpoints for each individual object, in children and adults. The results of study four suggest viewpoint selection to be under the influence of at least two major factors: object structure, i.e. principal axis of elongation, aspect ratio and object sides of maximal elongation; and an object reference frame defined by alignment with the gravitational upright.
Overall, this thesis shows active object inspection to be a reliable empirical effect, with potential for novel contributions to the study of visual object recognition.
0623: Experimental psychology
0633: Cognitive psychology