Hypothesized that elevated ratio of phenylalanine to tyrosine in blood of children with phenylketonuria uniquely affects cognitive functions dependent on prefrontal cortex because of the special sensitivity of prefrontally projecting dopamine neurons to small decreases in tyrosine. Found that children whose phenylalanine levels were three to five…

Three experiments examined effects of language on developing knowledge of distinction between real and apparent properties. Found that when Spanish verbs for "to be" -- "Ser" and "Estar" -- were substituted for "is,""Ser" gave the Spanish-speaking and bilingual speakers a unique advantage in…

Presents a teacher's method of staying in touch with his students' cognitive development. Offers his outline of four cognitive levels, with definitions, and types of student responses (from sixth- and eighth-grade students). (SR)

Ben, a good mathematics student, participated in a seven-week study. Describes three tasks that reflect impact of textbooks, real-life connections, and mathematical symbols. Shows that Ben's notion of one-half was task-dependent, concrete, and based on physical actions. (NI)

Two experiments investigated whether children, averaging three years old, used a transition theory in their developing understanding of mind or whether their interpretation moved from a desire-focused theory to a mature theory that attributed a greater role to beliefs. Findings supported a transition theory interpretation over competing…

Tested 4-month-olds' memory for surface feature and location information following brief occlusions. Found that when target objects were images of female faces or monochromatic asterisks, infants increased looking times following changes in identity or color but not changes in location or combinations of feature and location. When objects were…

Presents a hybrid ACT-R model that shows U-shaped learning of the English past tense without direct feedback, changes in vocabulary, or unrealistically high rates of regular verbs. Illustrates that the model can learn the default rule, even if regular forms are infrequent. Shows that the model can explore the question of why there is a distinction…

Describes a student's unique perspective on the algorithm for finding equations of non-vertical lines given one point and the slope. Indicates that students had a better understanding of what they were doing. (KHR)

Examines ways to model the production function for cognitive achievement to capture theoretical notions that child development is a cumulative process involving family and school inputs and ability. Develops a modeling framework that accommodates several known estimating equations, discussing how to address data limitations and highlighting the…

Outlines five perspectives addressing alternate aspects of the development of children's source monitoring: source-monitoring theory, fuzzy-trace theory, schema theory, person-based perspective, and mental-state reasoning model. Discusses research areas with relation to forensic developmental psychology: agent identity, prospective processing,…

Looks at the general effects of bilingualism on cognitive development and highlights the specific effects of bilingualism on third language acquisition. Examines effects of bilingualism on cognitive development, metalinguistic awareness, and communicative skills, then focuses on the specific effects of bilingualism on third language proficiency by…

Developmentalists have overlooked the problem of the real impermanence of things. Though the metaphor of impermanence is central to Piagetian and neo-nativist accounts of representation, the development of the understanding of impermanence is unstudied. This article proposes that the development of the concept of impermanence is distinct from the…

Reports on connectionist models that simulated the formation of global-level and basic-level representations in young infants; revealed a global-to-basic order of category emergence; uncovered formation of two global-level representations--initial "self-organizing" perceptual level and subsequent "trained," non-perceptual…

Critiques the metaphor of child-as-theoretician. Argues that comparisons between the cognitive development of an individual and the historical development of a scientific theory are deeply misleading. Further argues that, although there are similarities between children's cognitive enculturation and adults' continuing education, individual…

Used a framework-isolating analysis of knowledge and control of processing components to investigate preschoolers' acquisition of cardinality. Found that cardinality emerges gradually in children between ages three and five. Also, tasks that increase the processing burden of a basic counting problem by adding demands for either analysis or control…