Overshadowing of explicitly unpaired conditioned inhibition is disrupted by preexposure to the overshadowed inhibitor

In two conditioned lick-suppression experiments with rats, the interaction of preexposure to a target stimulus and subsequent overshadowing of conditioned inhibition treatment was examined. Blaisdell, Bristol, Gunther, and Miller (1998) have demonstrated that stimulus preexposure and overshadowing counteract each other in their effects on Pavlovian excitation, producing strong excitatory responding to the target stimulus. In the present experiments, a conditioned inhibition analogue of this effect was examined. Overshadowing of conditioned inhibition (i.e., attenuation of inhibitory control of behavior by the target stimulus) was demonstrated when a more salient stimulus was compounded with the target inhibitor during conditioned inhibition training. However, the overshadowing deficit was attenuated by preexposing the target stimulus prior to overshadowing treatment. To account for this phenomenon, we contrast the comparator hypothesis (Miller & Matzel, 1988) with contemporary models that focus on associative acquisition.     

Decrements in knee extensor and flexor strength are associated with performance fatigue during simulated basketball game-play in adolescent,male players

This study quantified lower-limb strength decrements and assessed the relationships between strength decrements and performance fatigue during simulated basketball. Ten adolescent, male basketball players completed a circuit-based, basketball simulation. Sprint and jump performance were assessed during each circuit, with knee flexion and extension peak concentric torques measured at baseline, half-time, and full-time. Decrement scores were calculated for all measures. Mean knee flexor strength decrement was significantly (P < 0.05) related to sprint fatigue in the first half (R = 0.65), with dominant knee flexor strength (R = 0.67) and dominant flexor:extensor strength ratio (R = 0.77) decrement significantly (P < 0.05) associated with sprint decrement across the entire game. Mean knee extensor strength (R = 0.71), dominant knee flexor strength (R = 0.80), non-dominant knee flexor strength (R = 0.75), mean knee flexor strength (R = 0.81), non-dominant flexor:extensor strength ratio (R = 0.71), and mean flexor:extensor strength ratio (R = 0.70) decrement measures significantly (P < 0.05) influenced jump fatigue during the entire game. Lower-limb strength decrements may exert an important influence on performance fatigue during basketball activity in adolescent, male players. Consequently, training plans should aim to mitigate lower-limb fatigue to optimise sprint and jump performance during game-play.     

Enhancing the Executive Functions of 3‐Year‐Olds in the Dimensional Change Card Sort Task

Executive functions enable flexible thinking, something young children are notoriously bad at. For instance, in the dimensional change card sort (DCCS) task, 3‐year‐olds can sort cards by one dimension (shape), but continue to sort by this dimension when asked to switch (to color). This study tests a prediction of a dynamic neural field model that prior experience with the postswitch dimension can enhance 3‐year‐olds' performance in the DCCS. In Experiment 1A, a matching game was used to preexpose 3‐year‐olds (n = 36) to color. This facilitated switching from sorting by shape to color. In 3 , 3‐year‐olds (n = 18) were preexposed to shape. This did not facilitate switching from sorting by color to shape. The model was used to explain this asymmetry.     

A toy model that predicts the qualitative role of bar bend in a push jerk

In this work, we describe a simple coarse-grained model of a barbell that can be used to determine the qualitative role of bar bend during a jerk. In simulations of this model, we observed a narrow time window during which the lifter can leverage the elasticity of the bar in order to lift the weight to a maximal height. This time window shifted to later times as the weight was increased. In addition, we found that the optimal time to initiate the drive was strongly correlated with the time at which the bar had reached a maximum upward velocity after recoiling. By isolating the effect of the bar, we obtained a generalized strategy for lifting heavy weight in the jerk.     

Politically correct hiring Will Destroy higher education

Aaron Wildavsky, a founder and president of the California Association of Scholars, died on September 4, at the much too early age of 63. Professor Wildavsky's life exemplified a total commitment to the university, and his achievements were prodigious. He authored or edited, alone or with colleagues, some three dozen books, and he wrote hundreds of articles. In the thirty years he spent at Berkeley, he was at various times chairman of the Department of Political Science and founding Dean of the Graduate School of Public Policy. He also found time to serve as president of the American Political Science Association and the Policy Studies Association, and to be active in myriad other organizations. When Yale, where he had earned his doctorate in 1959, earlier this year made him an honorary Doctor of Social Science, it stated, “You have improved every institution with which you have been associated.” Aaron Wildavsky was profoundly concerned about the future of the university, the institution that he loved so much and served so well. At the Fourth National Conference of the NAS, held in San Francisco this past April, he expressed his fears about the effect of politically correct faculty hiring practices on the long-range future of education. Academic Questions here reproduces his remarks in the hope—one that, in fact, he shared—that for once his predictions will be proved wrong.     

Neural information retrieval: at the end of the early years

A recent “third wave” of neural network (NN) approaches now delivers state-of-the-art performance in many machine learning tasks, spanning speech recognition, computer vision, and natural language processing. Because these modern NNs often comprise multiple interconnected layers, work in this area is often referred to as deep learning. Recent years have witnessed an explosive growth of research into NN-based approaches to information retrieval (IR). A significant body of work has now been created. In this paper, we survey the current landscape of Neural IR research, paying special attention to the use of learned distributed representations of textual units. We highlight the successes of neural IR thus far, catalog obstacles to its wider adoption, and suggest potentially promising directions for future research.     

Effects of two instructional sets on the validity of the Kaufman assessment battery for children–nonverbal scale with a group of severely hearing impaired children

The purpose of the study was to investigate the use of the Kaufman Assessment Battery for Children (K-ABC)–Nonverbal Scale with severely hearing impaired children. The K-ABC was administered to 49 children enrolled at a public residential school for the deaf. Test instructions were given to one group employing American sign language (ASL), plus pantomime and gestures, while the other group received pantomime and gesture (PG) instructions only. No significant difference was found between the two group mean nonverbal K-ABC scores. Also, neither group scored significantly different from the K-ABC norms. Both groups scored significantly lower than K-ABC norms on the Spatial Memory subtest. Significant correlations were found between the K-ABC and Wechsler Intelligence Scale for Children-Revised (WISC-R). A significant correlation also was found between K-ABC scores and Reading Comprehension. A post hoc analysis of data found that, regardless of the instructional set, the children scored significantly lower on the Nonverbal K-ABC than they did on the WISC-R Performance Scale. The study provides support for the appropriateness of the K-ABC for use with deaf children.     

Alternate Conceptions of Preservice Elementary Teachers: The Itakura Method

In this study, we determined the effectiveness of the inquiry-based Itakura method for mediating alternate conceptions of preservice elementary teachers (N = 38) in an integrated mathematics, science, and technology methods course. We investigated alternate conceptions in the expansion of solids due to heating. There was a significant increase in participants’ immediate learning gains after participating in the Itakura method. Retention data was gathered after 1, 2, and 3 months. After 3 months, retention levels dropped slightly, but not significantly. Responses revealed that the majority of the participants did not revert back to alternate conceptions after 3 months.