Three experiments test object permanenece in 3 1/2- and 4 1/2-month-old infants, and use an impossible-possible-habituation event format. The 4 1/2-month-olds, and the 3 1/2-month-olds who were fast habituators, look reliably longer at the impossible than at the possible event. Results seriously question Piaget's (1954) claims regarding the age at…

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)

The relationship between early language and cognition was studied in 20 children between 1 and 2 years of age. Four cognitive areas were tested: object permanence, means-end, play, and imitation. Results indicated that specific cognitive skills seem temporarily associated with some linguistic abilities, although attainment of skills can be…

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)