Accurate representation of a changing environment requires individuation--the ability to determine how many numerically distinct objects are present in a scene. Much research has characterized early individuation abilities by identifying which object features infants can use to individuate throughout development. However, despite the fact that…

The current study evaluated the relative roles of conceptual knowledge and executive control on the development of "categorical flexibility," the ability to switch between simultaneously available but conflicting categorical representations of an object. Experiment 1 assessed conceptual knowledge and executive control together; Experiment 2…

In manual search tasks designed to assess infants' knowledge of the object concept, why does search for objects hidden by darkness precede search for objects hidden by visible occluders by several months? A graded representations account explains this decalage by proposing that the conflicting visual input from occluders directly competes with…

Eight- to 12-month-olds might make A-not-B errors, knowing the object is in B but searching at A because of ancillary (attention, inhibitory, or motor memory) deficits, or they might genuinely believe the object is in A (conceptual deficit). This study examined how diligently infants searched for a hidden object they never found. An object was…

Background: Social understanding is often thought to be relatively "protected" in children with Down's syndrome (DS) and to underlie the outgoing personality characteristically attributed to them. This paper draws together findings from our studies of behaviours during object concept testing, generally considered a theoretically "pure" measure of…

We introduce computer-based methodologies for investigating object identification in 3- to 5-year-old children. In two experiments, preschool children and adults indicated when they could identify degraded pictures of common objects as those pictures either gradually improved or degraded in clarity. Clarity transformations were implemented in four…