Controlling the Ground Reaction Force During Lifting

The control of the ground reaction force vector relative to the center of gravity (CoG) was examined while subjects performed a back-lifting task. Six male subjects (aged 24.0 +/- 2.5 years) repeatedly lifted a barbell. A biomechanical analysis that used a linked segment model revealed that the summed rotations of body segments during lifting yielded a specific rate of change of the angular momentum of the entire body. This equaled the external moment provided by Fsubg; relative to CoG. This implies that multisegment movements involve control of the angular momentum of the entire body through an appropriately directed Fsubg;. Thus, in dynamic tasks Fsubg; is pointed away from rather than lined up with the CoG, as is the case in static tasks.     

Analysing and evaluating problem-solving discussions

In this article, the conceptual instrument that pragma-dialectical argumentation theory offers is elaborated for the analysis and evaluation of problem-solving discussions. The elaboration is aimed expressly at taking into account the discussion character of the discourse, in order to show how the developing process evolves and what the obstacles are therein. In addition, it focuses expressly on the verbal behaviour of the participants and on showing how this behaviour controls the evolving process. The analysis and evaluation is based on insights and methods of conversational analysis and discourse analysis. One fragment of a problem-solving discussion is analysed and evaluated.     

Children's capacity to agree to psychological research: knowledge of risks and benefits and voluntariness

A series of studies investigated the capacity of children between the ages of 7 and 12 to give free and informed consent to participation in psychological research. Children were reasonably accurate in describing the purpose of studies, but many did not understand the possible benefits or especially the possible risks of participating. In several studies children's consent was not affected by the knowledge that their parents had given their permission or by the parents saying that they would not be upset if the children refused. In contrast, other studies found that children were much more likely to stop their participation if the experimenter said explicitly that she would not be upset if they stopped. We suggest that experimenters should pay more attention to describing the possible risks and benefits of participation in research, and that they should also make it clearer to children that they are free to stop once they have begun.     

The equalitarian dogma revisited

Henry Garrett (1961), a president of the American Psychological Association, claimed that “the equalitarian dogma,” the belief that Blacks and Whites are genetically equal in cognitive ability, was the “scientific hoax of the century.” Since then, the dogma has become more ingrained, despite increased contrary evidence. The dogma has been perpetuated by intimidation as well as by pious thinking. Its long endurance is a scandal of great proportion and illuminates how science works, and sometimes does not. I discuss (a) current international data on race differences; (b) their genetic and evolutionary origins; (c) political fallout from my presentations; (d) corruption of scholarship that has occurred, illustrated partly by the example of Cyril Burt; and (e) what should be done to improve matters.     

Conditional Control of Fluid Consumption in an Occasion Setting Paradigm Is Independent of Pavlovian Associations

Drug states, flavors, and contextual cues were each trained as conditional discriminative stimuli to control a saccharin-LiCl association. In transfer tests, drug states transferred control over consumption to other flavored solutions and to food. Contexts and flavors transferred control only to other flavored solutions. Pavlovian control groups given direct pairings of context-LiCl or flavor-LiCl did not show reliable transfer. However, these control groups did show greater or the same aversion to the specific context or flavor predicting LiCl compared to the context or flavor discrimination groups. The dissociation of the discrimination and Pavlovian groups on transfer versus preference tests suggests that performance on the occasion setting task cannot be due to simple excitation or learning about a unique compound cue. Data from extinction procedures provide further support for the dissociation between simple excitation and occasion setting.     

Are beliefs brain-states? And if they are what might that explain?

Philosophical Studies -