Abrupt luminance change pops out; abrupt color change does not

The present studies investigated whether an isoluminant color change pops out, indicating that it can be detected preattentively in parallel. The results of Experiment 1 show that an abrupt color change presented on an equiluminant background does not pop out. However, when the color change is accompanied by a small luminance change, it does pop out. The results of Experiment 2 show that the pop-out is fully due to the luminance change and not to the color change. The results of Experiments 3 and 4 show that the failure to find a pop-out at equiluminance cannot be attributed to the limited temporal resolution for chromatic stimuli. The results of Experiment 5 show that particular search strategies cannot be responsible for the obtained results. The results are in agreement with physiological findings regarding the parvo and magno systems.     

Legal and ethical issues in conducting research on alcohol and drug use with children: a reaction to Havey and Dodd

Although research pertaining to alcohol and drug use by children clearly is very important for our field, it also presents a number of difficult ethical and legal challenges. In this article we react to Havey and Dodd's research (1995, this issue), commenting specifically on their use of a passive consent procedure. Problems with this aspect of their methodology are reviewed in relationship to best research practices, the U.S. Constitution, case law, federal statutes, and the ethical codes of the American Psychological Association, the National Association of School Psychologists, and the American Educational Research Association.     

MENTAL PROCESSES INVOLVED IN RAPID LOGICAL REASONING

S medslund , J. Mental processes involved in rapid logical reasoning. Scand. J. Psychol ., 1968, 9, 187–205.—Approximate reaction times of adult subjects were recorded in three studies of addition and subtraction of units, and in one of transitive inference. Transformations such as from 'V has more than H' to 'H has less than V' were found to be important determinants of RT in additionlsubtraction. Under some conditions subjects preferred to combine the first two elements in a triad of operations first, under other conditions they seemed to select inversions (V + 1 & V−1) first. Symmetries (V + 1 & H +1) were apparently never preferred. All transitive tasks seemed to be converted into normal form (A>B ∓ B>CorA < B & B < C) before they were solved.     

THE ACQUISITION OF CONSERVATION OF SUBSTANCE AND WEIGHT IN CHILDREN

S medslund , J. The acquisition of conservation of substance and weight in children. I. Introduction. Scand. J. Psychol ., 1961, 2 , 11–20.—This is the first in a series of articles concerning the problem of how children acquire the concepts of conservation of substance and weight. The four alternative interpretations of nativism, maturation theory, learning theory and equilibration theory are discussed. It is concluded that nativism and maturation theory do not account for the known facts. An important issue is whether the concepts are established by external reinforcement (learning theory) or by a process of inner equilibration, as maintained by Piaget.     

The relationship of young adolescent Children's Depression Inventory (CDI) scores to their social and cognitive functioning

The relationship of young adolescents' scores on the Children's Depression Inventory (CDI) to subjective and objective indices of their social and cognitive functioning was examined. Subjects were 89 young adolescents (11–15 years old), their parents, and their social studies teachers. The correlations of adolescents' CDI scores with recent school grades, objective ratings of overt social behavior, and measures of adolescent social and cognitive competence as perceived by the adolescent, both parents, and the teacher were examined. CDI scores were significantly and negatively correlated with school grades, behavioral ratings of positive social communication, and adolescent, mother, father, and teacher perceptions of the adolescents' social and cognitive competence. The relationship of these findings to those of other CDI validity studies is discussed.This research was supported, in part, by the William T. Grant Foundation and the University of Georgia's Institute for Behavioral Research.     

A generalization of Takane's algorithm for dedicom

An algorithm is described for fitting the DEDICOM model for the analysis of asymmetric data matrices. This algorithm generalizes an algorithm suggested by Takane in that it uses a damping parameter in the iterative process. Takane's algorithm does not always converge monotonically. Based on the generalized algorithm, a modification of Takane's algorithm is suggested such that this modified algorithm converges monotonically. It is suggested to choose as starting configurations for the algorithm those configurations that yield closed-form solutions in some special cases. Finally, a sufficient condition is described for monotonic convergence of Takane's original algorithm.Financial Support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged. The authors are obliged to Richard Harshman.     

Aiming at the top? Upward social comparison of abilities after failure

This study examined the effects of feedback on a task on information seeking and partner preferences as forms of social comparison. It was predicted that subjects who experienced failure and perceived control over future performance would, for reasons of self-improvement, choose more strongly upward a comparison other than subjects who experienced success or perceived no control. In the experiment, 121 college students were given either failure, average, or success feedback on a bogus test for either a stable or a controllable ability. Next, the subjects choose a comparison other whose test material they would examine, and a comparison other as a partner for writing an evaluation of the test. As predicted, the preferences for information seeking and affiliation were more strongly upward when subjects experienced failure than when subjects experienced success. Perceived control partly resulted in more strongly upward choices in information seeking for subjects experiencing failure.     

Turbo Pascal timing routines for the IBM microcomputer family

Two Turbo Pascal (versions 3.0 and 4.0) software timers for the IBM microcomputer family are described: one with a 55-msec resolution and another with a 1-msec resolution. Both can be implemented without additional hardware requirements. The 55-msec timer makes use of the system-time-of-day clock; the 1-msec timer is a Turbo Pascal translation of the timer described by Bührer, Sparrer, and Weitkunat (1987). The logic of each timer is shown by a short demonstration program.