Practice variability and children's motor behavior

This research investigated Schmidt's variability-of-practice prediction and the breadth-of-a-movement class. Schmidt's hypothesis was tested by varying the parameters of ball and distance in overarm throwing. Breadth-of-a-movement class was tested by employing two novel tasks not previously used in variability-of-practice designs. 203 kindergarten and first-grade subjects were randomly assigned to one of four conditions, three experimental and one control. Experimental subjects performed 45 trials in their respective training conditions, weight, distance, weight/distance, in one session. Two novel striking tasks were administered to all subjects pre- and posttest to assess the variability-of-practice hypothesis, and the generalizability of overarm throwing and striking. Variability-of-practice in the overarm throw appeared to strengthen the striking schemas of the kindergarten boys. Results suggest some support for the inclusion of throwing and striking in a single-movement class. The concept, breadth of movement class, however, requires further study.     

Book reviews

Blanchard, R. J. & Blanchard, D. C. (Eds.). (1986). Advances in the study of aggression, Volume 2. Orlando, Florida: Academic Press. Pp. 228. ISBN 0-12-037702-5. $60.00 (hardback).

Dobbing, J. (Ed.). (1987). Sweetness. Berlin: Springer-Verlag. Pp. 282. ISBN 3-540-17045-6. £42.

Ellen, P. & Thinus-Blanc, C. (Eds.). (1987). Cognitive processes and spatial orientation in animal and man. Dordrecht: Martinus Nijhoff. Vol. 1. Experimental animal psychology and erhology. Pp. 331. ISBN 90-247-3447-9. £60.95. Vol. 2. Neurophysiology and developmental aspects. Pp. 321. ISBN 90-247-3448-7. £60.95     

Problem solving in infancy: the emergence of an action plan.

Young children's strategies were evaluated as they grasped and used objects. Spoons containing food and toys mounted on handles were presented to 9-, 14-, and 19-month-old children with the handle alternately oriented to the left and right. The alternating orientations revealed strategies that the children used for grasping items. Younger children usually reached with their preferred hand, disregarding the item's orientation. In the case of the spoon, this strategy produced awkward grasps that had to be corrected later. Older children anticipated the problem, alternated the hand used, and achieved an efficient radial grip (i.e., handle grasped with base of thumb toward food or toy end) for both orientations. A model of the development of action-selection strategies is proposed to illustrate planning in children younger than 2 years.     

Women's language: Uncertainty or interpersonal sensitivity and emotionality?

Six differences in linguistic behavior in same-sex and mixed-sex problem-solving groups were explored. Small groups of all women, all men, and mixed sex were run and videotaped. Linguistic behavior was assessed through a content analysis of four syntactic categories: intensifiers, modal constructions, tag questions, and imperative constructions in question form. Support was found for the hypothesis of Key (1975) and Lakoff (1975) that women, as compared with men, use more linguistic categories that connote uncertainty. Support was also found for these authors' hypotheses that (1) women use more linguistic forms that connote uncertainty when men are present than when men are absent, and (2) men are more likely to interrupt women than women are likely to interrupt men. The results are discussed from the perspectives of women's role (supportive behavior and minority status) and women's culture (interpersonal sensitivity and emotionality).This report is a revision of a paper presented at the Pioneers for Century III Conference, Cincinnati, Ohio, April 1976.     

Can values moderate the attitudes of right-wing authoritarians?

This investigation explored how right-wing authoritarianism (RWA) and endorsement of egalitarian beliefs may interact to determine attitudes toward immigrants, homosexuals, and African Americans. Study 1 (N = 239) found that RWA was negatively related to evaluations of immigrants for those who weakly endorsed egalitarian beliefs. In contrast, endorsement of egalitarian beliefs was associated with positive evaluations of immigrants for both low and high RWAs. RWA did not interact with egalitarianism to determine attitudes toward homosexuals or African Americans. Study 2 analyzed data from the 1992 National Election Study and replicated these effects in a young adult (age < or = 24) sample (n = 102) using moral traditionalism as a proxy for RWA. Partial support for the hypotheses also was found in the adult (age > or = 25) sample (n = 1,257). It is concluded that when tradition and/or social norms offer unclear positions, endorsement of egalitarian beliefs influences the attitudes of authoritarians.     

What the precedence effect tells us about room acoustics

Sound produced in a room is typically followed by numerous reflected sounds from nearby surfaces; yet we perceive a single sound source. This perceptual phenomenon, known as the precedence effect, has long been assumed to involve echo suppression, but the nature of this suppression remains unclear. In two experiments, we investigated whether information about the lagging sound's location was perceived. Our hypothesis was that such information is critical because reflected sound can function to inform the listener about objects and structures in the room. Listeners reported hearing more echoes under a stimulus situation that simulated sudden, unexpected changes in the location of the lagging sounds, as compared with stable stimulus conditions. Placement of lagging sounds' locations proved to be critical in that a sudden shift per se did not disrupt the fusion aspect of the precedence effect; the new location had to occupy a site that specified a new reflecting surface. Perception of echoes appears to be modulated by room acoustic information contained in reflected sound and listeners' expectations about this.     

Book reviews

MARCUS, M. P. A Theory of Syntactic Recognition for Natural Language. Cambridge, Massachusetts, and London, England: The MIT Press. 1980. Pp. 335. £15.50.

LASSMAN, F. M., FISCH, R. O., VETTER, D. K. and LA BENZ, E. S. Early Correlates of Speech, Language, and Hearing. Littleton, Mass.: PSG Publishing Co. 1980. Pp. 858. ISBN 0 88416 214 1.