Rats obtained food pellets on a variable-interval schedule of reinforcement by nose poking a lighted key. After training to establish baseline performance (with the mean variable interval set at either 60, 120, or 240 s), the rats were given free access to food during the hour just before their daily session. This satiation operation reduced the…

The influence of body parts on 4-month-olds' categorization of cats and dogs was examined using a visual preference procedure. Infants were familiarized with pictures of exemplars from one of two categories, cat or dog. In test, looking time to an out-of-category exemplar was compared to looking time to a novel within-category exemplar with one…

Objective: To investigate relationships among family risk factors, childhood firesetting and animal cruelty, and adolescent delinquency. Method: In 1990, mothers and children participating in a 10-year prospective study provided information about family risk factors and childhood problem behavior. Subsequent interviews with 86% of the sample in…

Research has demonstrated that rats' rates of operant behavior maintained by 1% sucrose reinforcement in the first half of an experimental session are heightened when food-pellet reinforcers, rather than 1% sucrose, will be available in the second half. Experiment 1 showed that rats that had been displaying this positive induction effect acquired…

Forward blocking is one of the best-documented phenomena in Pavlovian animal conditioning. According to contemporary associative learning theories, forward blocking arises directly from the hardwired basic learning rules that govern the acquisition or expression of associations. Contrary to this view, here the authors demonstrate that blocking in…

Modern low-cost data acquisition systems enable pupils to study the voltage-current characteristics of a wide range of different materials and devices in a quick and convenient way. In particular, it is possible to study materials, such as meat and vegetables, not normally associated with school physics experiments.

CPEB-1 is a sequence-specific RNA binding protein that stimulates the polyadenylation-induced translation of mRNAs containing the cytoplasmic polyadenylation element (CPE). Although CPEB-1 was identified originally in Xenopus oocytes, it has also been found at postsynaptic sites of hippocampal neurons where, in response to N-methyl-D-aspartate…

The rabbit nictitating membrane (NM) response underwent successive stages of acquisition and extinction training in both delay (Experiment 1) and trace (Experiment 2) classical conditioning. In both cases, successive acquisitions became progressively faster, although the largest, most reliable acceleration occurred between the first and second…

Mutations in the amyloid precursor protein (APP) gene inducing abnormal processing and deposition of [beta]-amyloid protein in the brain have been implicated in the pathogenesis of Alzheimer's disease (AD). Although Tg2576 mice with the Swedish mutation ("hAPPswe") exhibit age-related [Alpha][beta]-plaque formation in brain regions like the…

The sleeping neocortex shows nested oscillatory activity in different frequency ranges, characterized by fluctuations between "up-states" and "down-states." High-density neuronal ensemble recordings in rats now reveal the interaction between synchronized activity in the hippocampus and neocortex: Electroencephalographic sharp…

To test the hypothesis that social rearing may induce malleability, socially reared and socially isolated mallard duck, "Anas platyrhynchos," embryos and hatchlings were exposed to the maternal call of a chicken, "Gallus gallus domesticus," until 48 h after hatching. The hatchlings were then tested with the chicken call versus…

Gottlieb promoted the value of a developmental psychobiological systems approach to the study of human development. This approach recognizes the importance of comparative, animal-based research to advancing our understanding of the complexities and dynamics of the process of development. The major contribution of animal developmental studies is…

Across the United States, today's farm operators face continuing challenges from global competition, increasing production costs, changing technology, increased regulations, scarce resources, and lower profit margins. To face these challenges, farm operators need to gather and utilize information allowing them to make informed decisions. Several…

"Science Briefs" summarize the findings and implications of a recent study in basic science or clinical research. This Brief summarizes the findings and implications of "Moderate Fetal Alcohol Exposure Impairs the Neurogenic Response to an Enriched Environment in Adult Mice" (I. Y. Choi; A. M. Allan; and L. A. Cunningham). Observations of mice…

Where does cellular respiration take place? How does a plant make food and in turn use the food to produce its own energy? Do animals carry on this process also? To help students answer these and other questions, have them build a model leaf, plant cell, and animal cell. This hands-on project allows students to see and manipulate the reactants and…