Visual perception of surface curvature: psychophysics of curvature detection induced by motion parallax

The continuous approach to optic-flow processing shows that the curvature of a moving surface is related to a second spatial derivative of the velocity field, the spin variation (Droulez & Cornilleau-Pérès, 1989). With this approach as a theoretical framework, visual sensitivity to the curvature of a cylinder in motion was measured using a task of discrimination between cylindrical and planar patches. The results confirm the predictions suggested by the theory: (1) Sensitivity to curvature was always greater when the cylinder axis and the frontal translation were parallel than when they were orthogonal. The ratio of curvature detection thresholds in the two cases was between 1.3 and 2.5; the value predicted from the spin variation theory is about 2. (2) Sensitivity to curvature increased strongly with the velocity of the motion but was only weakly affected by its amplitude and the duration of viewing for the range of values used in our experiments.     

Using item-specific instructional information in achievement modeling

The problem of detecting instructional sensitivity (item basis) in test items is considered. An illustration is given which shows that for tests with many biased items, traditional item bias detection schemes give a very poor assessment of bias. A new method is proposed instead. This method extends item response theory (IRT) by including item-specific auxiliary measurement information related to opportunity-to-learn. Item-specific variation in measurement relations across students with varying opportunity-to-learn is allowed for.This paper was presented at the 1987 AERA meeting in Washington, DC. This research was supported by grant OERI-G-86-003 from the Office of Educational Research and Improvement, Department of Education. The author thanks Michael Hollis and Chih-fen Kao for valuable research assistance, and appreciates valuable comments made by an anonymous reviewer.     

Influence of sport participation upon sex role orientation of caucasian males and their attitudes toward women

Differences in psychological androgyny and attitudes toward women were examined in male Caucasian intercollegiate contact and noncontact sport athletes and male Caucasian college nonathletes. Contact athletes in the sports of football and wrestling, noncontact athletes in the sports of baseball and track and field, and nonathletes completed the Attitudes Toward Women Scale (ATWS) and the Bem Sex Role Inventory (BSRI) to assess egalitarian attitudes toward women and sex role orientation. Results of analyses of variance (ANOVAs) on the ATWS indicate that athletes as a group possessed more conservative, traditional attitudes toward women than did nonathletes, but that no differences existed between contact sport athletes and noncontact sport athletes. Results of ANOVAs and chi-square analyses on the BSRI indicated no differences between groups regarding sex role orientation based upon self-perceptions of masculinity and femininity.     

Resistance revisited

It was a coincidence that I was asked to talk about resistance at Ground Rounds at the University of Texas, Department of Psychiatry, on the tenth anniversary of mailing the first version of Death of Resistance to a journal in 1979. Although the paper was subsequently rejected 17 times and revised six times, it was eventually published inFamily Process (de Shazer, 1984). I still insist that the concept of resistance was a bad idea for therapists to have in their heads.This paper was presented April 14, 1989, at Ground Rounds, University of Texas, Southwest Medical Center, Department of Psychiatry, Dallas, Texas.     

Factor structure in groups selected on observed scores

A new method is proposed for estimating factor means and factor covariances in a group of individuals selected on their observed scores. The selection variable is, for example, the total score on an admissions test. Given a factor model for the test items based on the group of test takers, we may be interested in the factor structure for those in the top quartile. The differences in factor means and covariances between this selected group and the full group gives useful information both on successful test performance and on test validity. The new method draws on the classic Pearson-Lawley selection formulas. It avoids the fallacy of factor analysis on the selected group, which would lead to incorrect estimates. The new method is applied to a simple factor structure model for the GMAT test. Although the majority of the GMAT items test verbal skills, it is found that a quantitative factor shows the greatest change in moving from average to top quartile test takers.     

Image Attributions and Smoking Intentions Among Seventh Grade Students

Previous research has indicated that adolescents who intend to smoke differ from those who do not intend to smoke in the imagery they associate with smoking. The present study examined relationships among self-image, ideal self-image, image of smokers in general and image of models in cigarette ads for seventh-grade students. The strongest finding was a positive correspondence of smokers image to self-image in predicting intention to smoke cigarettes. This correspondence between smokers image and self-image derived from a relative depression of self-image in combination with a relative elevation of smokers image for youth who were more likely to report intentions to smoke. There was also a trend for the ideal self-image of youth with greater intentions to smoke to be similarly depressed. It is suggested that when both self-concept and aspirations for self-improvement are diminished, smoking may seem particularly desirable as a means of enhancing identity.     

PSYCHOLOGY AND HEALTH: CONTRIBUTIONS OF PSYCHOLOGY TO THE IMPROVEMENT OF HEALTH AND HEALTH CARE

Psychology as both a science and a profession has been closely identified with other disciplines in the broad field of health since the turn of the century. Recent advances in health care have reinforced the growing belief that the promotion of health and the prevention and treatment of illness can be greatly enhanced by incorporating the scientific findings and modern technology of psychology into everyday practices. Outlining the contributions of psychology to health care throughout the world is the primary purpose of this report. In this brief survey, only some of the most timely and relevant issues can be mentioned, together with examples of current work in the field. The reader interested in pursuing these psychological contributions more thoroughly is encouraged to review pertinent references from the citations at the end of this report. After an introductory overview, special attention is given to each of the major areas within the broad field of health care where psychological applications have been particularly useful.     

On structural equation modeling with data that are not missing completely at random

A general latent variable model is given which includes the specification of a missing data mechanism. This framework allows for an elucidating discussion of existing general multivariate theory bearing on maximum likelihood estimation with missing data. Here, missing completely at random is not a prerequisite for unbiased estimation in large samples, as when using the traditional listwise or pairwise present data approaches. The theory is connected with old and new results in the area of selection and factorial invariance. It is pointed out that in many applications, maximum likelihood estimation with missing data may be carried out by existing structural equation modeling software, such as LISREL and LISCOMP. Several sets of artifical data are generated within the general model framework. The proposed estimator is compared to the two traditional ones and found superior.The research of the first author was supported by grant No. SES-8312583 from the National Science Foundation and by a Spencer Foundation grant. We wish to thank Chuen-Rong Chan for drawing the path diagram.