Shape-from-shading depends on visual, gravitational, and body-orientation cues

The perception of shading-defined form results from an interaction between shading cues and the frames of reference within which those cues are interpreted. In the absence of a clear source of illumination, the definition of 'up' becomes critical to deducing the perceived shape from a particular pattern of shading. In our experiments, twelve subjects adjusted the orientation of a planar disc painted with a linear luminance gradient from one side to the other, until the disc appeared maximally convex-that is, until the luminance gradient induced the maximum perception of a three-dimensional shape. The vision, gravity, and body-orientation cues were altered relative to each other. Visual cues were manipulated by the York Tilted Room facility, and body cues were altered by simply lying on one side. The orientation of the disc that appeared maximally convex varied in a systematic fashion with these manipulations. We present a model in which the direction of perceptual 'up' is determined from the sum of three weighted vectors corresponding to the vision, gravity, and body-orientation cues. The model predicts the perceived direction of 'up', contributes to our understanding of how shape-from-shading is deduced, and also predicts the confidence with which the 'up' direction is perceived.     

The Parents Matter! Program Interventions: Content and the Facilitation Process

The Parents Matter! Program (PMP) has developed three interventions for parents of 4th and 5th grade African-American children (9–12 years old). The overarching goal of all three interventions is to provide parents with knowledge, skills, and support for enhancing their efforts to raise healthy children. The interventions are: (1) Enhanced Communication and Parenting (five 2 -hour sessions), (2) Brief Communication and Parenting (single 2 -hour session), and (3) General Health (single 2 -hour session). This article discusses the development of these interventions, presents an overview of the content of each intervention, and discusses issues related to the facilitation/presentation of these interventions.     

Repetition blindness: out of sight or out of mind?

Does repetition blindness represent a failure of perception or of memory? In Experiment 1, participants viewed rapid serial visual presentation (RSVP) sentences. When critical words (C1 and C2) were orthographically similar, C2 was frequently omitted from serial report; however, repetition priming for C2 on a postsentence lexical decision task was equivalent whether or not C1 was similar to C2. In Experiment 2, participants monitored RSVP sentences for a predetermined target. Participants frequently failed to detect the target when it was preceded by an orthographically similar word. In Experiment 3, the authors investigated the role of the attentional blink in this effect. These experiments suggest that repetition blindness is a failure of conscious perception, consistent with predictions of the token-individuation hypothesis.     

The effect of health value and ethnicity on the relationship between hardiness and health behaviors

Associations among hardiness, health value, and health protective behaviors were examined as a function of ethnicity among 80 African American and 100 European American college students. The role of health value as moderator versus mediator in the hardiness-health behavior link was explored. Racial differences in correlations among hardiness, control, and commitment were found, with stronger relations for African American than European Americans. Moderate positive relations between hardiness, control, commitment, and health value for African American, as contrasted with weak relations between commitment and health value for European Americans, were also shown. A partial mediational effect for health value with personal distress and moderator effects for health value with personal distress and health habits were found for African American only. Race predicted hardiness variables, tobacco and alcohol use, personal distress, and health habits beyond what was accounted for by occupation and income. The ramifications of these data with regard to future studies on hardiness, health value, and health behaviors for African American are discussed.     

School-year employment among high school students: effects on academic, social, and physical functioning

This study describes the effects of different weekly work intensity levels on adolescent functioning in a sample of 3,083 high school students in rural South Texas, where economically disadvantaged and Hispanic youth are heavily represented. Anonymous surveys were conducted in 10th- and 12th-grade students' classrooms in 1995. The following effects were associated with long hours of weekly employment during the school year: (1) decreased performance/engagement in school and satisfaction with amount of leisure time, and (2) increased health risk behaviors and psychological stress. The effects of school-year work on academic factors and health behaviors differed by grade, but not by race/ethnicity, parent education, or race/ethnicity and parent education considered together. It was concluded that parents and professionals should continue to monitor the number of weekly hours that students work during the school year.     

Cognitive behaviour therapy for eating disorders: a "transdiagnostic" theory and treatment

This paper is concerned with the psychopathological processes that account for the persistence of severe eating disorders. Two separate but interrelated lines of argument are developed. One is that the leading evidence-based theory of the maintenance of eating disorders, the cognitive behavioural theory of bulimia nervosa, should be extended in its focus to embrace four additional maintaining mechanisms. Specifically, we propose that in certain patients one or more of four additional maintaining processes interact with the core eating disorder maintaining mechanisms and that when this occurs it is an obstacle to change. The additional maintaining processes concern the influence of clinical perfectionism, core low self-esteem, mood intolerance and interpersonal difficulties. The second line of argument is that in the case of eating disorders shared, but distinctive, clinical features tend to be maintained by similar psychopathological processes. Accordingly, we suggest that common mechanisms are involved in the persistence of bulimia nervosa, anorexia nervosa and the atypical eating disorders. Together, these two lines of argument lead us to propose a new transdiagnostic theory of the maintenance of the full range of eating disorders, a theory which embraces a broader range of maintaining mechanisms than the current theory concerning bulimia nervosa. In the final sections of the paper we describe a transdiagnostic treatment derived from the new theory, and we consider in principle the broader relevance of transdiagnostic theories of maintenance.     

Personality and the predisposition to engage in risky or problem behaviors during adolescence

Longitudinal data from a representative sample of 1,978 Black and White adolescents were used to examine the role of personality in multiple risk or problem behaviors. Results indicate that covariation among diverse behaviors (educational underachievement, delinquent behavior, substance use, sexual behavior) can be adequately modeled by a single higher order factor, and that impulsivity and avoidance coping serve as generalized risk factors for involvement in these behaviors. Whereas none of the personality variables examined explained change in problem behaviors once established, avoidance coping prospectively predicted involvement among a subgroup of adolescents with little or no prior involvement. Results suggest that dysfunctional styles of regulating emotions and emotionally driven behaviors are core features of risky or problem behaviors during adolescence.