Achievement in mathematics in grades 9 and 11 in Limpopo Province of South Africa: introduction of a problem-based approach

800 students in Grades 9 and 11 of schools in the Central Region of the Limpopo Province of South Africa completed the Study Orientation Questionnaire in Mathematics. Mean age in Grade 11 was 17.5 yr. (SD = 1.4) and in Grade 9 15.1 yr. (SD = 1.2). Intervention was aimed at teachers and students in this group. Teachers in the trained group received training in a problem-based approach to teaching and learning in mathematics and introduced these principles into their classes. Analysis of variance on the differences between post- and pretest scores of the six subscales and the marks in mathematics and English yielded no effects for grade, sex, or grade after 6 mo. Pearson correlations for students in Grade 11 were positive between study orientation and achievement in mathematics. Improving teachers' training and expertise, transforming disadvantaged learning environments, and developing necessary formal and informal mathematical knowledge seem both essential and difficult.     

Information along contours and object boundaries

F. Attneave (1954) famously suggested that information along visual contours is concentrated in regions of high magnitude of curvature, rather than being distributed uniformly along the contour. Here the authors give a formal derivation of this claim, yielding an exact expression for information, in C. Shannon's (1948) sense, as a function of contour curvature. Moreover, they extend Attneave's claim to incorporate the role of sign of curvature, not just magnitude of curvature. In particular, the authors show that for closed contours, such as object boundaries, segments of negative curvature (i.e., concave segments) literally carry greater information than do corresponding regions of positive curvature (i.e., convex segments). The psychological validity of this informational analysis is supported by a host of empirical findings demonstrating the asymmetric way in which the visual system treats regions of positive and negative curvature.     

Visual identification and spatial location in Alzheimer's disease

Twelve patients with Alzheimer's disease (AD) and 15 healthy elderly control subjects were shown sets of luminance-defined letters, texture-defined letters, luminance-defined squares, and texture-defined squares. They were asked to name the letters or point to the target square on each page. The stimuli were graded into four levels of difficulty based on the amount of contrast between the figure and the background. Performance was measured in terms of the maximum level of difficulty at which the participant correctly identified or located the three figures. Contrary to expectations, no significant difference was found between the performance of AD patients and control subjects on texture discrimination tasks vs. luminance discrimination tasks. However, results indicate that AD patients are impaired in performing a task requiring them to locate a texture-defined target of known shape in a noisy background field. By contrast, AD patients show no significant deficit in a task requiring them to locate a texture-defined shape in a known location. This argues that the observed deficit in the location task is not due to a failure in the system that discriminates target texture from background texture (since both location and identification tasks require the same textural discriminations), but rather to an impairment of the system responsible for "finding things" (i.e., locating known targets at unknown locations). This observation suggests that AD patients may suffer selective damage to the dorsal "Where" pathway, which is responsible for localizing objects in space.     

Influences of Marital Conflict on Child Adjustment: Review of Theory and Research

This review summarizes the literature on the relationship between marital conflict and child maladjustment with an emphasis on variables that qualify, explain the association, or both. Following a historical review, the modest findings on the strength of the association between marital conflict and child maladjustment is explored. The definition of marital conflict is clarified through specification of its various dimensions (frequency, intensity, content, resolution). The role of variables that serve to moderate and/or mediate the relationship between marital conflict and child maladjustment are elaborated. Mediating models include exposure theories (Modeling, Cognitive–Contextual effects: appraisal of threat and blame, and Emotional Insecurity) and changes in the parent–child relationship (Spillover). Variables that moderate or qualify the relationship include children's cognitions and behaviors, contextual factors, and demographic differences. A model is presented summarizing these mechanisms. Research recommendations are proposed and the clinical implications of this literature are addressed.     

Differentiation of Self, Stress, and Emotional Support as Predictors of Psychological Distress

We explored the relations among stress, emotional support, and differentiation of self from the family of origin as predictors of psychological distress in a sample of 200 college students. First, we investigated the discrepant findings of Murdock and Gore (Contemp Fam Ther 23: 319–335, 2004) and Skowron et al. (J Couns Dev 82: 69–78, 2004) regarding the relationships among stress, differentiation, and symptoms (a question of mediation vs. moderation). Second, we examined the role of emotional support in concert with stress and differentiation. When both stressful events and perceived stress were measured, differentiation of self was found to be a significant partial mediator of their effects on psychological distress. Emotional support was also found to partially mediate the relationship between differentiation of self and psychological distress. Differentiation of self partially mediated the relationship between actual and perceived stress, and perceived stress partially mediated the relationship between differentiation of self and psychological distress.     

The Personality Psychopathology-Five (PSY-5): recent constructive replication and assessment literature review

The Personality Psychopathology-Five (PSY-5; Harkness & McNulty, 1994) is a model of individual differences relevant to adaptive functioning in both clinical and non-clinical populations. In this article, we review the development of the PSY-5 model (Harkness, 1992; Harkness & McNulty, 1994) and discuss the ways in which the PSY-5 model is related to and distinct from other 5-factor models. Using different methods and measures, the dimensions of the PSY-5 model have been constructively replicated (Lykken, 1968) by Tackett, Silberschmidt, Krueger, and Sponheim (2008) and by Watson, Clark, and Chmielewski (2008), and dimensions congruent with the PSY-5 have even been suggested for the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; Krueger et al., 2011). PSY-5 Scales can be scored from the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher et al., 2001), the MMPI-Adolescent version (MMPI-A; Butcher et al., 1992), and the Restructured Form of the MMPI-2 (MMPI-2-RF; Ben-Porath & Tellegen, 2008). Because the largest body of research exists for the MMPI-2-based scales, we focus our review of the literature on the MMPI-2-based PSY-5 scales (Harkness, McNulty, & Ben-Porath, 1995), but we briefly cover the small, but growing, body of MMPI-A and MMPI-2-RF PSY-5 scales research. We show that the PSY-5 research literature includes a wide variety of psychometric methodologies as well as diverse samples and clinical problems. An integrative summary reprises the theory behind each PSY-5 construct and links it to the reviewed literature. Advantages and limitations of MMPI-2-based PSY-5 scales are discussed.