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)

Suggests that Greenberg's challenge to the centrality of object permanence in developmental thinking reveals that developmentalists' theories about childhood speak about their own self-images. Notes that developmentalists have been guilty of not only the object permanence fallacy but also the genetic fallacy, or the mistaken belief that describing…

Adult and 10- and 12-month olds participated in two experiments to determine reliance of infants on object-kind information in solving problems of object individuation. Findings converge with those of object-first hypothesis of developmental course of object individuation. Findings suggest that young infants may represent one concept as criteria…

Evaluated in three experiments a dynamic systems theory account of perseverative errors on "A-not-B" task. Found that 9-month-olds perseverated when reaching for identical targets, but made nonperseverative responses when reaching in the presence of a highly distinctive B target. Reach direction was jointly determined by target's…

Maintains that Muller and Overton (1998) misrepresent her theory of infant concept formation in infancy, makes corrections to their representation, and notes that her theory was developed in part because of the lack of detailed mechanisms in Piaget's theory to account for concept formation. Argues that Muller and Overton's proposed alternative…

Recent work suggests that infants rely on mechanisms of object-based attention and short-term memory to represent small numbers of objects. Such work shows that infants discriminate arrays containing 1, 2, or 3 objects, but fail with arrays greater than 3 [Feigenson, L., & Carey, S. (2003). Tracking individuals via object-files: Evidence from…

The present research investigated whether 13.5-month-old infants would attribute to an actor a disposition to perform a recurring action, and would then use this information to predict which of two new objects--one that could be used to perform the action and one that could not--the actor would grasp next. During familiarization, the infants…

Research over the past 20 years has revealed that even very young infants possess expectations about physical events, and that these expectations undergo significant developments during the first year of life. In this article, I first review some of this research, focusing on infants' expectations about occlusion, containment, and covering events,…

Experience with a variety of symbolic artifacts has been proposed as a mechanism underlying symbolic development. In this study, the parents of 120 2-year-old children who participated in symbolic object retrieval tasks completed a questionnaire regarding their children's naturalistic experience with symbolic artifacts and activities. In separate…

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)

Experiment one tested 9- and 16-month-old children on a modification of Piaget's Stage IV object permanence task, examining infants' use of information from previous experiences with an object and from a recent hiding to locate a hidden object. In experiment two, two-, two-and-a-half-, and four-year-old children additionally received verbal…

Low birth weight preterm multiple birth infants do lag behind initially in mental and motor development, but they are equal in development with normal peers by the age of two. It was inferred that the multiple caretaking situation did not interfere with the infants' specific attachment to their mothers. (Author/RH)

Premature infants with subependymal or intraventricular hemorrhage took longer to habituate on a habituation task, and scored lower on a measure of mental development, than did other premature infants or full-term infants. Both groups of premature infants were less successful than full-term infants on an object permanence task. (BC)