Shuttlebox avoidance to intense white noise: Acquisition and the Kamin effect in rats

Experiment I demonstrated shuttlebox avoidance conditioning using intense white noise as a UCS. Ten rats were given 25 trials a day for 6 days. Escape latencies declined and avoidance responses increased over trial blocks. Experiment II provided support for a functional similarity between shock as a UCS and intense noise as a UCS by demonstrating the Kamin effect following incomplete shuttlebox training to noise. Separate groups of rats were given 25 trials followed by an additional 25 trials either 0, 1, 4, or 24 h later. The U-shaped Kamin effect was evident in the avoidance measure. A similar but inverted U-shaped function was obtained for the escape latency measure. Escape latencies were longer on retraining than on original training at 1 h but not at 0, 4, or 24 h after original training.     

Effects of US parameters on classical conditioning of cat hindlimb flexion

Unconditioned stimulus (US) intensity and duration were manipulated to determine their effects on cat hindlimb flexion conditioning. Seven consecutive days of acquisition training of a hindlimb flexor response to a tone conditioned stimulus (CS) were followed by 2 days of extinction. Eight animals in each of 12 groups received a 1-, 2-, 3-, or 4-mA, 60-Hz shock delivered to the right hindleg for 25, 50, or 100 msec as the US. Analysis of conditioned-response (CR) frequency indicated that conditioned responding was a positive function of both the intensity and duration of shock, although these variables did not interact with one another. CR latency and amplitude were decreased and increased, respectively, by increases in US intensity. The pattern of results reported here may support a contiguity notion of conditioning, and are discussed in the context of other conditioning preparations.     

Exploring the Form and the Function: a Review of Science Discourse Frameworks in the Service of Research and Practice

Research in Science Education - The importance of how classroom discourse can be used to support science learning has gained national attention with respect to both science teaching and research...     

Creative block play

Blocks should be part of the daily free choice activity in early childhood settings for children between the ages of two and six. Large enough segments of time need to be allotted for blockbuilding activities, so that children can build various structures and also have enough time to use blocks for social and dramatic play. Eugene F. Provenzo, Jr. is Associate Professor of Education at the University of Miami. Arlene Brett is Associate Professor of Elementary Education at the University of Miami. This article is excerpted from The Complete Block Book, ©1983 Syracuse University Press, 1600 Jamesville Avenue, Syracuse, New York 13210. Photographs © 1983 by Michael Carlebach. The book is available from the publisher in paperback edition for $12.95 (plus $1.25 for postage and handling).     

Electroconvulsive shock and learned helplessness in rats

Three experiments evaluated the effects of a single electroconvulsive shock in alleviating the learned helplessness effect in rats. The experiments differed primarily in terms of the location of the ECS treatment in the experimental sequence of events. In Experiment 1, ECS was given following helplessness training and testing and was evaluated during a retesting phase; in Experiment 2, ECS was given either immediately after helplessness training or immediately before helplessness testing; and, in Experiment 3, ECS was given prior to helplessness training. In all three experiments, significant helplessness effects occurred for subjects not receiving ECS but were absent in subjects receiving ECS. The data were compared with expectations arising from both amnesia-inducing and biochemical-change interpretations of the effects of ECS.     

Do baseball pitchers improve mechanics after biomechanical evaluations?

The purpose of this study was to determine how often flaws in pitching mechanics identified from biomechanical analysis are corrected. The biomechanics of 46 baseball pitchers were evaluated twice, with an average of 12 months (range 2–48 months) between evaluations. Pitchers were healthy at the time of both evaluations, competing at the high school, college, minor league or Major League level. After warming up, each participant pitched 10 full-effort fastballs. Automated three-dimensional motion analysis was used to compute eight kinematic parameters which were compared with a database of elite professional pitchers. Flaws—defined as deviations from the elite range—were explained to each participant or coach after his initial evaluation. Data from the second evaluation revealed that 44% of all flaws had been corrected. Flaws at the instant of foot contact (stride length, front foot position, shoulder external rotation, shoulder abduction, elbow flexion) or slightly after foot contact (time between pelvis rotation and upper trunk rotation) seemed to be corrected more often than flaws near the time of ball release (knee extension and shoulder abduction). Future research may determine which level athletes or which training methods are most effective for correcting flaws.     

Early school entrance for intellectually superior children: An analysis

A four-year follow-up study comparing the performance of intellectually superior children admitted early to school and the performance of normal children admitted at the regular time is presented. Achievement scores, self-emotional adjustment, and school success (promotion/retention) are discussed. Results of a stepwise multiple linear regression reveal nonsignificant findings regarding variables that contribute to school success. The effects of early school admission involving “gifted” children are discussed.     

Kinematic and kinetic differences between left-and right-handed professional baseball pitchers

While 10% of the general population is left-handed, 27% of professional baseball pitchers are left-handed. Biomechanical differences between left- and right-handed college pitchers have been previously reported, but these differences have yet to be examined at the professional level. Therefore, the purpose of this study was to compare pitching biomechanics between left- and right-handed professional pitchers. It was hypothesised that there would be significant kinematic and kinetic differences between these two groups. Pitching biomechanics were collected on 96 left-handed pitchers and a group of 96 right-handed pitchers matched for age, height, mass and ball velocity. Student t-tests were used to identify kinematic and kinetic differences (p < 0.05). Of the 31 variables tested, only four were found to be significantly different between the groups. Landing position of the stride foot, trunk separation at foot contact, maximum shoulder external rotation and trunk forward tilt at ball release were all significantly greater in right-handed pitchers. The magnitude of the statistical differences found were small and not consistent with differences in the two previous, smaller studies. Thus, the differences found may be of minimal practical significance and mechanics can be taught the same to all pitchers, regardless of throwing hand.