Sixty infants divided evenly between 5 and 7 months of age were tested for their knowledge of object continuity versus discontinuity with a predictive tracking task. The stimulus event consisted of a moving ball that was briefly occluded for 20 trials. Both age groups predictively tracked the ball when it disappeared and reappeared via occlusion,…

This study investigated the ability of preterm infants to learn an object shape with one hand and discriminate a new shape in the opposite hand (without visual control). Twenty-four preterm infants between 33 and 34 + 6 gestational weeks received a tactile habituation task with either their right or left hand followed by a tactile discrimination…

This research examined the ability of young (N = 96) children to learn about a change in the location of a hidden object, either via an adult's verbal testimony or from direct observation. Thirty-month-olds searched with equal accuracy whether they were told about the change or directly observed it. By contrast, when 23-month-olds were told about…

Tested two competing hypotheses explaining infants' failure to search for an object in a new hiding place: (1) that the concept of object is not yet differentiated from the concept of place, and (2) that difficulties in spatial localization are responsible for the search failure. (Author/JMB)

A hypothesized developmental sequence of agent use in pretending was tested in 36 infants between 14 and 24 months of age and was compared with the development of object permanence. (JMB)

Changes in children's categorization behavior between 15 and 21 months of age and the relation of these changes to developments in language, object permanence, and means-end understanding are reported. (PCB)

Examined the role of perceptual-motor development in a typical Stage IV task. The performance of ten infants was compared on a Stage IV object permanence task when a cloth cover was used and when a small card cover was used. (JMB)

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…

Reports two experiments which were designed to establish whether errors in infants' manual searches for objects are caused by changes in the location of an object or by the change in the relation between old and new hiding places. (JMB)

Recent studies on the biological development of the prefrontal cortex in rhesus monkeys are reviewed. These studies have elucidated the basic neural circuitry underlying the delayed-response function in adult nonhuman primates and suggest that a critical mass of cortical synapses is important for the emergence of this cognitive function. (BN)

Reports two experiments in which eight patients with organic memory disorders exhibited a pattern of search behavior that resembled mnemonmic precedence--the ability to retrieve an object at an initial location, but not at a new location. (HOD)

Investigates whether 6- to 12-month-old infants' exposure to the successful search behavior of a sibling in two object-concept tasks would enhance infants' subsequent performance on these tasks. (HOD)

Compares two types of semantic development (the acquisition of disappearance words and success-failure words) to performance on two types of cognitive tasks (object-permanence and means-ends tasks) among infants. (HOD)

An investigation of Piaget's theory of object concept development through a series of six tasks administered in a combined longitudinal/cross-sectional design (which incorporated a number of methodological controls). Subjects were 36 infants who received the six tasks during each of three testing sessions over a 6-month period. (Author/ED)