Outcomes of Parent Education Programs Based on Reevaluation Counseling

We report two studies in which a parent education program based on Reevaluation Counseling was field-tested on mothers randomly assigned to treatment groups or equivalent, no-treatment comparison groups. The goal was to evaluate the program's viability, whether there were measurable effects, whether those effects were sustained over time, and whether the program was effective among diverse populations. The first study involved middle income, married mothers (n = 25) with at least one child younger than age five. Eleven members of the no-treatment group participated in the program three months later. Pretest, posttest, and follow-up measures included a parental attitude survey and a parenting stress index. The second study involved 18 black mothers with children enrolled in Head Start. Six members of the no-treatment group participated in the program two months later. Added to the pretest, posttest, and follow-up measures were a parent attitude research instrument and a parenting practices questionnaire. Results were replicated within and across studies. Significant effects suggest that the program can reduce parenting-related stress, improve parental attitudes, and encourage authoritative parenting practices, although some effects tend to diminish somewhat over time. The program appears viable with mothers of various social status groups.     

Cross-sectional and prospective associations between cognitive appraisals and posttraumatic stress disorder symptoms following stroke

This study examined cross-sectional and prospective associations between cognitive appraisals and posttraumatic stress disorder (PTSD) symptoms following stroke. While in hospital, stroke patients (n=81) completed questionnaires assessing cognitive appraisals (i.e., negative cognitions about the self, negative cognitions about the world, and self-blame) and PTSD symptoms. PTSD symptoms were assessed again 3 months later when all patients had been discharged from hospital (n=70). Significant correlations were found between the time 1 measures of negative cognitions about the self and the world, but not self-blame, and the severity of PTSD symptoms measured at time 1 and at time 2. Regression analyses revealed that cognitive appraisals explained a significant amount of variance in the severity of PTSD symptoms at time 1, with negative cognitions about the self-emerging as a significant predictor. In contrast, time 1 cognitive appraisals were unable to explain additional variance in time 2 PTSD severity over and above that explained by time 1 PTSD severity. The findings therefore provide only weak support for Ehlers and Clark's cognitive model of PTSD.     

Visual working memory represents a fixed number of items regardless of complexity

Does visual working memory represent a fixed number of objects, or is capacity reduced as object complexity increases? We measured accuracy in detecting changes between sample and test displays and found that capacity estimates dropped as complexity increased. However, these apparent capacity reductions were strongly correlated with increases in sample-test similarity (r= .97), raising the possibility that change detection was limited by errors in comparing the sample and test, rather than by the number of items that were maintained in working memory. Accordingly, when sample-test similarity was low, capacity estimates for even the most complex objects were equivalent to the estimate for the simplest objects (r= .88), suggesting that visual working memory represents a fixed number of items regardless of complexity. Finally, a correlational analysis suggested a two-factor model of working memory ability, in which the number and resolution of representations in working memory correspond to distinct dimensions of memory ability.     

Redness enhances perceived aggression, dominance and attractiveness in men's faces

In a range of non-human primate, bird and fish species, the intensity of red coloration in males is associated with social dominance, testosterone levels and mate selection. In humans too, skin redness is associated with health, but it is not known whether - as in non-human species - it is also associated with dominance and links to attractiveness have not been thoroughly investigated. Here we allow female participants to manipulate the CIELab a* value (red-green axis) of skin to maximize the perceived aggression, dominance and attractiveness of photographs of men's faces, and make two findings. First, participants increased a* (increasing redness) to enhance each attribute, suggesting that facial redness is perceived as conveying similar information about a male's qualities in humans as it does in non-human species. Second, there were significant differences between trial types: the highest levels of red were associated with aggression, an intermediate level with dominance, and the least with attractiveness. These differences may reflect a trade-off between the benefits of selecting a healthy, dominant partner and the negative consequences of aggression.     

The biasing of figure-ground assignment by shading cues for objects and faces in prosopagnosia

Prosopagnosia is defined by impaired recognition of the identity of specific faces. Whether the perception of faces at the categorical level (recognizing that a face is a face) is also impaired to a lesser degree is unclear. We examined whether prosopagnosia is associated with impaired detection of facial contours in a bistable display, by testing a series of five prosopagnosic patients on a variation of Rubin's vase illusion, in which shading was introduced to bias perception towards either the face or the vase. We also included a control bistable display in which a disc or an aperture were the two possible percepts. With the control disc/aperture test, prosopagnosic patients did not generate a normal sigmoid function, but a U-shaped function, indicating that they perceived the shading but had difficulty in using the shading to make the appropriate figure-ground assignment. While controls still generated a sigmoid function for the vase/face test, prosopagnosic patients showed a severe impairment in using shading to make consistent perceptual assignments. We conclude that prosopagnosic patients have difficulty in using shading to segment figures from background correctly, particularly with complex stimuli like faces. This suggests that a subtler defect in face categorization accompanies their severe defect in face identification, consistent with predictions of computational models and recent data from functional imaging.     

The role of occlusion in the perception of depth, lightness, and opacity

A theory is presented that explains how the visual system infers the lightness, opacity, and depth of surfaces from stereoscopic images. It is shown that the polarity and magnitude of image contrast play distinct roles in surface perception, which can be captured by 2 principles of perceptual inference. First, a contrast depth asymmetry principle articulates how the visual system computes the ordinal depth and lightness relationships from the polarity of local, binocularly matched image contrast. Second, a global transmittance anchoring principle expresses how variations in contrast magnitudes are used to infer the presence of transparent surfaces. It is argued that these principles provide a unified explanation of how the visual system computes the 3-D surface structure of opaque and transparent surfaces.     

Amygdala size and hypothalamus size predict social play frequency in nonhuman primates: a comparative analysis using independent contrasts

The amygdala and hypothalamus become sexually differentiated by gonadal hormones giving rise to sexually differentiated behaviors, which include play behavior. Phylogenetic comparative analyses test for relationships between social play and brain structure volumes. Relative volume of the amygdala and hypothalamus correlated with social play, but not nonsocial play, even after controlling for the size of other brain structures. The authors propose that behaviors such as social assessment, recognizing and responding to facial expression, and social response appropriateness, which are mediated by the amygdala, are developed through social play. Additionally, the hypothalamus may regulate the motivation to engage in play through positive reinforcement of pleasurable activity. Thus, the instinctive socio-emotive aspects of play in primates appear to be those regulated by the amygdala and hypothalamus.     

Toward a perceptual theory of transparency

Theories of perceptual transparency have typically been developed within the context of a physical model that generates the percept of transparency (F. Metelli's episcotister model, 1974b). Here 2 fundamental questions are investigated: (a) When does the visual system initiate the percept of one surface seen through another? (b) How does it assign surface properties to a transparent layer? Results reveal systematic deviations from the predictions of Metelli's model, both for initiating image decomposition into multiple surfaces and for assigning surface attributes. Specifically, results demonstrate that the visual system uses Michelson contrast as a critical image variable to initiate percepts of transparency and to assign transmittance to transparent surfaces. Findings are discussed in relation to previous theories of transparency, lightness, brightness, and contrast-contrast.