Stereo-motion cooperation and the use ofmotion disparity in the visual perception of 3-D structure

When an observer views a moving scene binocularly, both motion parallax and binocular disparity provide depth information. In Experiments lA-1C, we measured sensitivity to surface curvature when these depth cues were available either individually or simultaneously. When the depth cues yielded comparable sensitivity to surface curvature, we found that curvature detection was easier with the cues present simultaneously, rather than individually. For 2 of the 6 subjects, this effect was stronger when the component of frontal translation of the surface was vertical, rather than horizontal. No such anisotropy was found for the 4 other subjects. If a moving object is observed binocularly, the patterns of optic flow are different on the left and right retinae. We have suggested elsewhere (Cornilleau-Pérès & Droulez, in press) that this motion disparity might be used as avisual cue for the perception of a 3-D structure. Our model consisted in deriving binocular disparity from the left and right distributions of vertical velocities, rather than from luminous intensities, as has been done in classical studies on stereoscopic vision. The model led to some predictions concerning the detection of surface curvature from motion disparity in the presence or absence of intensity-based disparity (classically termedbinocular disparity). In a second set of experiments, we attempted to test these predictions, and we failed to validate our theoretical scheme from a physiological point of view.     

Mental rotation as a mediator for sex-related differences in visualization

This study was designed to analyze whether Mental Rotation (MR) played a role as a mediating variable for sex-related differences in Visualization (VZ). Two psychometric tests measuring MR and VZ were applied to a representative sample of 309 males and 390 females in their last year of high school. Three non-zero correlations between sex and MR, sex and VZ, and MR and VZ were found, and the effect of sex on VZ was eliminated when MR was introduced as a covariable. When three subgroups of different VZ ability were made by dividing up the VZ distribution by the first and third quartiles, sex-differences were only found for the high-scorers group, for which previous results were replicated. Results clearly indicate that MR is a plausible mediator variable for sex differences in VZ when such differences do exist. Theoretical, methodological and practical consequences of these results are discussed.     

Latinas with Arthritis: Effects of Illness, Role Identity, and Competence on Psychological Well-Being

Tested a theoretical model on the effects of social role identity, illness intrusion, and competence on psychological well-being among 109 low-income Latinas with arthritis. All six roles studied were rated as highly important identities. Sex-role nontraditionalism was associated with less importance of the homemaker, mother, and grandmother roles. Negative affect increased as a function of intrusions into valued identities. Having important role identities contributed to feelings of competence (i.e., self-esteem and self-efficacy), which in turn, contributed to psychological well-being. Competence also mediated the effects of pain, identity, and illness intrusions on psychological well-being. Results suggest competence processes play an important role in well-being.     

Personality and Job Performance in Financial Services Managers

This article presents research in which the Five Factor Model of personality was tested as a predictor of job performance. 125 financial services managers who had enrolled in a potential evaluation programme were given the NEO-FFI, a questionnaire designed for measuring the Big Five. Job performance was assessed using nine rating scales and they were grouped into two components: job problem-solving ability and job motivation. Also, one single scale for measuring global job performance was used. The results show that Neuroticism and Conscientiousness correlated with the two components and with the global measure of job performance. Extraversion, Openness and Agreeableness are correlated with one facet or with the global rating of job performance. Taken together, the results suggest that the Five Factor Model is a valid predictor of job performance. The implications of the results for practice and future research are discussed.     

BEHAVIORAL CUSPS: A DEVELOPMENTAL AND PRAGMATIC CONCEPT FOR BEHAVIOR ANALYSIS

Most concepts of development explain certain behavior changes as products or markers of the invariable succession of emerging periods, stages, refinements, or achievements that define and order much of an individual's life. A different but comparable concept can be derived from the most basic mechanisms of behavior analysis, which are its environmental contingencies, and from its most basic strategy, which is to study behavior as its subject matter. From a behavior-analytic perspective, the most fundamental developmental questions are (a) whether these contingencies vary in any systematic way across the life span, and thus make behavior change in a correspondingly systematic way; and (b) whether some of these contingencies and their changes have more far-reaching consequences than others, in terms of the importance to the organism and others, of the behavior classes they change. Certain behavior changes open the door to especially broad or especially important further behavior change, leading to the concept of the behavioral cusp. A behavioral cusp, then, is any behavior change that brings the organism's behavior into contact with new contingencies that have even more far-reaching consequences. Of all the environmental contingencies that change or maintain behavior, those that accomplish cusps are developmental. Behavior change remains the fundamental phenomenon of development for a behavior-analytic view; a cusp is a special instance of behavior change, a change crucial to what can come next.     

Axiomatic justifications of the utility principle: A formal investigation

It is argued that existing axiomatic theories of utility do not provide the utility principle or the principle of maximising expected utility with a formal justification. It is also argued that these theories only put mild constraints on a decision-maker in a decision-context. Finally, it is argued that the prospects are not particularly bright for finding formal non-circular arguments for the utility principle that do not rely on the law of large numbers.