Cooperative selection of movements: The optimal selection model

How one selects a movement when faced with alternative ways of doing a task is a central problem in human motor control. Moving the fingertip a short distance can be achieved with any of an infinite number of combinations of knuckle, wrist, elbow, shoulder, and hip movements. The question therefore arises: how is a unique combination chosen? In our model, choice is achieved by consideration of the similarity between the task requirements and the optimal biomechanical performance of each limb segment. Two variants of the model account for the movements that are selected when subjects freely oscillate the fingertip and when they tap against an obstacle. An important feature of both is that the impulse of collision with an obstacle (as in drumming with the hand or tapping with the finger) is assumed to be controlled in part by aiming for a point beyond the surface being struck. Thus, a force-related control variable may be represented and controlled spatially.     

Hemispheric asymmetries in the identification of band-pass filtered letters

Processing of band-pass filtered letters in the left versus right cerebral hemispheres (LH vs. RH) was examined. The present experiments constituted a partial replication of a study in which Peterzell, Harvey, and Hardyck (1989) found no hemispheric differences in accuracy or reaction time (RT) as a function of spatial frequency. However, methodological limitations of their study (e.g., the possibility that subjects were engaged in a detection, not identification, task) may have obscured possible hemispheric differences. We addressed these problems in the present study, obtaining significant hemisphere × spatial frequency interactions for RT andd', with RH advantages at low frequencies and LH advantages at high frequencies; however, these effects were not large in magnitude and were often restricted to particular dependent variables, stimulus sizes, and so forth. Hemispheric differences in response bias were also found.     

Questions of criteria: Reply to Peterzell (1997)

In a reply to our report on hemispheric differences in processing band-pass filtered letters (Christman, Kitterle, & Niebauer, 1997), Peterzell (1997) argues that our results are not attributable to hemispheric asymmetries in spatial frequency processing. Rather, Peterzell argues that factors such as response criteria and stimulus visibility can account for our results. We argue that our results are attributable (at least in part) to hemispheric asymmetries in spatial frequency processing, while at the same time we acknowledge the potential influence of other factors in the determination of hemispheric differences.     

模糊再认（FR）判断—元记忆领域的新方法

Ｈａｒｔ所开创的ＦＯＫ研究范式表明,在记忆的提取阶段由客体水平的回忆能引起元水平ＦＯＫ判断,但历来的研究都忽略了由再认也能引起一种元记忆判断,这就是“模糊再认判断”（即ＦＲ判断）．本文论述了ＦＲ判断的概念,特性和研究方法并加以实验验证．ＦＲ判断发生在记忆提取阶段,有着与ＦＯＫ判断同等重要的研究价值和相似的研究方法．ＦＲ研究范式给予元记忆研究以新的思想和方法．     

Correlation,partial correlation,and causation

Philosophers and scientists have maintained that causation, correlation, and “partial correlation” are essentially related. These views give rise to various rules of causal inference. This essay considers the claims of several philosophers and social scientists for causal systems with dichotomous variables. In section 2 important commonalities and differences are explicated among four major conceptions of correlation. In section 3 it is argued that whether correlation can serve as a measure of A's causal influence on B depends upon the conception of causation being used and upon certain background assumptions. In section 4 five major kinds of “partial correlation” are explicated, and some of the important relations are established among two conceptions of “partial correlation”, the conception of “screening off”, the conception of “partitioning”, and the measures of causal influence which have been suggested by advocates of path analysis or structural equation methods. In section 5 it is argued that whether any of these five conceptions of “partial correlation” can serve as a measure of causal influence depends upon the conception of causation being used and upon certain background assumptions. The important conclusion is that each of the approaches (considered here) to causal inference for causal systems with dichotomous variables stands in need of important qualifications and revisions if they are to be justified.     

THE REBIRTH OF MEANING: A HUMAN PROBLEM

Abstract. With the rise of the social sciences, it was expected they would replace philosophy in solving practical problems and improving the human condition. Ernest Becker's The Birth and Death of Meaning describes this project to cure humankind, but also points out the failures along the way. Nonetheless, a new psychology, based on a final science of humanity, still can accomplish this task. While Becker admits an incurable religious tendency in human nature, he counts on its being satisfied through a "new heroism." However, in light of past failures, it is worthwhile taking another look at religion as a source for "the rebirth of meaning."