The effects of delayed and displaced visual feedback on motor control

Developments in television technology have made possible new approaches to the study of the role of visual feedback in motor control. In two experiments using a special videodisc recording and playback system, the effects of delaying for 66 msec a subject's view of his own hand during a target-directed movement was investigated. The observed effects of such visually delayed feedback compared to spatially distorted feedback produced by prisms led to three major conclusions: (a) despite the behavioral similarity (overshooting) induced by the two kinds of altered feedback, the role of each in the visual-motor control loop is different; (b) adaptation to and the after effect of the two kinds of altered feedback are based on different control mechanisms (c) the processing and use of visual information in hand control requires less time than previous experiments have indicated.     

Religion,psychology, and mental health: The problems of partnership

While a current and increasingly popular trend is toward partnerships between religion and psychology in the area of mental health, and especially toward the use of psychological ideas and techniques by pastoral counselors, modern psychology and traditional religion are divided in significant ways over several normative issues. Too often these issues are minimized or overlooked. But unless these issues—which carry significant sociocultural implications as well as implications for our definitions of individual well-being—are acknowledged and subjected to critical considerations, partnerships between religion and psychology must be far more cautiously constructed and must be subjected to far more systematic thinking about the differences which separate the two.This article is based on a paper delivered at the Seventh Annual Clinical-Community Conference on Psychology and Religion at the University of Maryland in November, 1978.     

Abortion: A Jewish view

A practicing physician reviews the contribution of Jewish ethics, as it relates to the structure of Jewish law, to the issue of abortion. The topics approached include the status of the fetus, the relationship of fetus to mother, abortion and murder, therapeutic abortion, and the rights of the mother. The discussion describes rabbinic answers to abortion requests and is followed by a summary of the Jewish attitudes toward termination of fetal life. An appendix is provided, dealing with central aspects of Jewish ethics, the structure of Jewish law, their relationship, and a note on abortion legislation in Israel.     

On a theorem of Feferman

Summary In this paper I have argued that Feferman's theorem does not signify the existence of skeptic-satisfying consistency proofs. However, my argument for this is much different than other arguments (most particularly Resnik's) for the same claim. The argument that I give arises form an analysis of the notion of expression, according to which the specific character of that notion is seen as varying from one context of application (of a result of arithmetic metamathematics) to another.I want to thank Dale Gottlieb, Mike Resnik, John Corcoran, Nicolas Goodman and Stewart Shapiro for careful and helpful commentary on an ancestor of this paper that was delivered at the Western Division Meetings of the APA in 1977.     

A twin study of specific behavioral problems of socialization as viewed by parents

Our study focused on the etiology of specific behavioral problems rather than on a global syndrome such as hyperactivity. As a first step in studying specific behavioral problems, we revised the Conners (1970) Parent Symptom Rating questionnaire to improve its factor structure. Our revised instrument and the testretest reliabilities of its 12 scales are described. A classical twin analysis comparing intraclass correlations for 54 pairs of identical twins and 33 pairs of same-sex fraternal twins indicated substantial genetic influence on behavioral problems in schoolaged children. We wish to express our gratitude for the Spencer Foundation's support of this research.     

Focused memory search in fact retrieval

Several studies of fact retrieval have shown that the more facts a person learns about a concept, the longer it takes him or her to retrieve any of these facts. This result has been interpreted to mean that retrieval of a fact about a concept involves a search of all facts stored in memory with that concept. In the present study, it is suggested that retrieval involves not an unfocused search of all facts stored with a concept, but rather a focused memory search that examines relevant stored facts and ignores irrelevant information. This argument is supported by three experiments in which subjects first learned simple facts (e.g., “The banker likes horses”) and then made speeded true-false decisions for test probes le.g., “The banker likes elephants”). Specifically, results suggest that facts stored with a concept may be organized into subsets. For example, a person’s knowledge about Richard Nixon might be organized into subsets concerning Nixon’s resignation, his trips to China, his family, and so on. The data further suggest that a person attempting to retrieve a fact about a concept (e.g., the name of Nixon’s wife) may simply decide which subset is most likely to contain the desired fact (e.g., the subset concerning Nixon’s family) and search that subset. If the sought-for fact is found in this subset, the search process terminates. If, however, the desired information is not located, other subsets of facts may be searched before the retrieval attempt is given up. The notion that memory search focuses on relevant stored facts and ignores irrelevant information may help to explain why experts (i.e., people who know a large number of facts about a topic) do not experience great difficulty in retrieving facts in their areas of expertise.     

Interactive presentation in multitrial free recall

This paper explores whether free recall performance and organization can be facilitated using computer-controlled interactive presentation, where stimulus presentation on Trial N+1 depends on the individual subject’s prior recall history. A series of experiments investigated the effects of two types of response-contingent presentation order manipulations and of selective tagging manipulation designed to highlight the presentation of previously nonrecalled items. An initial experiment using 20-word lists showed no differences among groups, due to a ceiling effect. Two subsequent experiments, using longer lists (30 and 40 words), found that recall and subjective organization were increased by selective tagging and by presentation orders that preserved the subject’s prior order of recall. The results demonstrate that subjects’ previous recall histories contain information that can be used to facilitate recall. The potential of other interactive manipulations is discussed.