Mirror use by African Grey parrots (Psittacus erithacus).

Two Grey parrots (Psittacus erithacus) were tested on various types of mirror use: mirror image stimulation, mirror-mediated object discrimination, and a simple form of mirror-mediated spatial locating. During exposure to a mirror, neither bird clearly demonstrated self-exploratory behavior but responded instead in ways similar to those of marmosets, monkeys, dolphins, extremely young children (     

Category learning deficits in Parkinson's disease.

Sixteen patients with Parkinson's disease (PD), 15 older controls (OCs), and 109 younger controls (YCs) were compared in 2 category-learning tasks. Participants attempted to assign colored geometric figures to 1 of 2 categories. In rule-based tasks, category membership was defined by an explicit rule that was easy to verbalize, whereas in information-integration tasks, there was no salient verbal rule and accuracy was maximized only if information from 3 stimulus components was integrated at some predecisional stage. The YCs performed the best on both tasks. The PD patients were highly impaired compared with the OCs, in the rule-based categorization task but were not different from the OCs in the information-integration task. These results support the hypothesis that learning in these 2 tasks is mediated by functionally separate systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use and maintenance of strategies: The influence of accessibility to knowledge.

Conducted 2 experiments in which the interaction between strategy use and accessibility to relevant knowledge was investigated. Ss were asked to memorize a list of categorizable words, and use of a categorization strategy was assessed. Typicality of the category exemplars was varied in a between-Ss fashion to manipulate accessibility to relevant knowledge and the S's experience with the strategy. Ss were then given a 2nd list of categorizable words to memorize, and the use of a categorization strategy was again assessed. In Exp 2, attributional data regarding strategy use were also collected. Results from the 2 experiments show that variations in accessibility to knowledge have a significant effect on strategy use on the 1st memorization trial. Experiencing highly typical items on the 1st list was found to be associated with continued use of the strategy on the 2nd list (i.e., ease of use on the 1st trial affected maintenance of the strategy). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic crack growth prediction in rails with BEM

Durability and damage tolerance calculations are typically based on experimental data or analytical studies of simplified cases. In this paper, a new numerical approach is described which can be used with the full model loading to compute the stress intensity factors and also to automatically predict how cracks will propagate.The benefits of the full numerical computation of the stress field are numerous, accurate prediction of crack growth, improved stress intensity data and more accurate prediction of life, thus providing an accurate method for the forensic analysis of failures.The crack growth process can be modelled with a variety of crack growth models relating the rate of crack growth to the computed stress intensity factors. The crack growth itself can include the effects of multiple load cases including the effect of residual stress fields.The crack growth process itself is fully automated by automatically re-meshing the crack surface and the nearby surfaces of the structure. The crack growth process is aided by the use of a fracture wizard that enables the necessary components for the analysis to be selected and the analysis to be controlled.Applications will be presented describing the potential applications of the method to the growth of cracks in rail components.     

Effects of reciprocal peer tutoring on academic achievement and psychological adjustment: A component analysis.

A component analysis of the reciprocal peer tutoring (RPT) strategy was performed, which previous research had demonstrated to be effective in producing cognitive gains, lowering subjective distress, and enhancing course satisfaction. One hundred students were randomly assigned to one of four groups designed to systematically compare the RPT strategy with its hypothesized components: dyadic, mutual exchange, and structured-learning format. Pretest analyses revealed no significant group differences in demographic variables or pretest scores on course examinations and self-report inventories of subjective distress. Further analyses supported past findings on the superiority of the RPT strategy. This superiority was attributed to the RPT group's unique combination of elements: preparing to teach a peer teaching a peer, and accountability for this process. We discuss implications for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Partner unsupportive responses, avoidant coping, and distress among women with early stage breast cancer: Patient and partner perspectives.

This 18-month longitudinal study examined the associations among partner unsupportive behavior, avoidant coping, and distress experienced by 219 women with early stage breast cancer. The role of patient and partner ratings of unsupportive behavior were evaluated. Results indicated that patient and partner ratings of unsupportive behavior were highly correlated. Growth curve modeling suggested that unsupportive behavior, from both patient and partner perspectives, predicted more avoidant coping and distress. When partner and patient perceptions were placed in the same model, patient perceptions mediated the association between partners' ratings of their unsupportive behavior and patient distress. Avoidance also mediated the association between unsupportive behavior and distress, extending prior cross-sectional findings. Results highlight the long-term detrimental effects of partners' unsupportive behavior on the quality of life of women with early stage breast cancer. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective processing of threat cues in posttraumatic stress disorder.

Vietnam combat veterans with (n?=?15) and without (n?=?15) posttraumatic stress disorder (PTSD) performed a modified Stroop task in which they named the colors of neutral words (e.g., INPUT), positive words (e.g., LOVE), obsessive-compulsive disorder (OCD) words (e.g., GERMS), and PTSD words (e.g., BODYBAGS). In contrast to normal controls, PTSD patients took significantly longer to color-name PTSD words than to color-name neutral, OCD, and positive words. Because Stroop interference reflects involuntary semantic activation, it may provide a quantitative measure of intrusive cognitive activity, the hallmark symptom of PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity issues in clinical assessment.

The data investigators should provide to support the validity of inferences they make based on scores from a measure depend on (a) whether the measure is assumed to assess a hypothetical construct or behavior and (b) the purposes for which the measure is intended. The authors distinguish between the representational phase of validity assessment, which establishes that a measure produces scores that reflect the construct or behavior it purports to assess, and the elaborative validity phase, in which the meaning and utility of scores are examined. Key issues relevant to convergent, discriminant, and criterion-related validity are examined for measures of latent traits or constructs and then for measures of behaviors or response classes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frustration, connectivity, and the glass transition

The concepts of connectivity, localization, and frustration are explored in relation to glass formation in amorphous materials. First, the concept of eigenclusters to geometrically characterize correlations in amorphous materials is introduced, and discussed in detail for both the Ising ferromagnet and Ising spin glass models. Second, a new, glass-forming percolation model that contains frustration as the essential ingredient, and exhibits two percolation transitions, is discussed. This new model gives new insights into frustrated systems, and applications to the Ising spin glass model and other glass-forming systems are discussed. In particular, we propose the possibility that the occurrence of a percolation-type transition at temperatures above the glass transition temperature may be a general feature of glass-forming systems. The important role of computer simulations in probing the mechanism of glass formation is emphasized.     

Efficacy of self-administered treatment programs: Meta-analytic review.

Using meta-analysis, we examined the efficacy of self-administered treatments. Self-administered treatments were compared with no treatment and with therapist-administered treatments. Results indicated that self-administered treatments were reliably more effective than no treatment and that differences between self-administered and therapist-administered treatments were nonsignificant. Effect sizes for type of target problem (e.g., phobias, affective disturbances) were comparable. These results suggest that self-administered treatments in general are effective in comparison with no treatment. The limitations of this review are noted, including those that preclude the conclusion that self-administered treatments are as effective as therapist-administered programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)