Individual differences in timing of discrete and continuous movements: a dimensional approach

This study investigated aspects of individual differences in timing of continuous and discontinuous movements to different pacing signals (auditory or visual), pacing intervals (500, 650, 800, 950 ms), and across effectors (dominant versus non-dominant hand). Correlation and principal component analysis demonstrated that a single statistical dimension accounted for up to 60 % of the explained variance in discontinuous tasks and 25 % of the variance in continuous tasks, when applied to performance obtained from tasks conducted with different effectors and at different pacing rates. Correlation analysis of factor scores representing effector and rate independent task performances showed that timing of discrete or continuous movements can be associated with modality independent mechanisms. Timing variability from discrete and continuous trials was not significantly correlated. This study goes beyond previous correlational work on individual differences in discrete and continuous movements, demonstrating that individual differences in discrete (event-based) or continuous (emergent) motor timing tasks can be modeled as distinctive statistical components with dissimilar capability to capture effector, rate, and modality independent variance.     

Trajectories of Adolescent Psychopathic Traits

There is growing evidence that psychopathic traits are stable across the adolescent developmental period. Yet, no previous studies have examined the longitudinal course of these traits across adolescence. In this study, we examined joint developmental trajectories of grandiose-manipulative traits, callous-unemotional traits, and impulsive-irresponsible behavior and how these trajectories were related to changes in parental behavior and delinquency over time. Participants were 1,068 adolescents from a community sample, who were followed annually over 4 years. Overall, our results showed that a four-class latent class growth model best represented the developmental pattern of adolescent psychopathic traits. Although the majority of adolescents showed low or moderate initial levels that also decreased over time, there was a small group of adolescents who, despite significant decreases in two out of three dimensions, still maintained relatively high levels on all three dimensions. We also found that parental behavior and delinquency developed differently for the groups over time, with the high-decreasing group engaging in more delinquent behavior over time and experiencing more negative parental behavior than any other group. In sum, our findings suggest that there is a group of adolescents at particular risk for negative development.     

Perceived sources and levels of stress,general self-efficacy and coping strategies in preclinical dental students

Dental education programs are known to be highly stressful and stress can affect general health. The aims were to identify sources of stress among preclinical students and to evaluate their perceived levels of stress, self-efficacy and effective coping strategies in a private dental school. One hundred preclinical students in a Turkish private dental school were surveyed using dental environment stress (DES), perceived stress (PSS), general self-efficacy (G-SES) and brief coping scales (Brief-COPE). Age, gender, history of psychiatric treatment, factors that affected the choice of dentistry, choice rank of dental school, scholarship and income was recorded. ‘Exams and grades’ followed by ‘Fear of failing course or year’ were found to be the most stressprovoking factors. The most and the least stressprovoking DES domains were ‘Workload’ and ‘Social stressors’, respectively. ‘Social stressors’ affected male more than female (p < .05). The most and the least common coping strategies were found to be ‘Planning’, and ‘Drug’, respectively. Female used ‘Instrumental support’ more than male (p < .05). Demographic factors had impact on the perceived stress factors and levels, as well as coping strategies. Unlike previous studies establishing high stress levels in dental students, preclinical students displayed moderate level of stress. Clinical dental education might be more responsible for creating stress.     

Short report: correlates of functional disability with disease activity in elderly patients with rheumatoid arthritis

Rheumatoid arthritis (RA) prevalence increases with age and old people are special patient population. The recognition of functional disability related to RA could be challenging in elderly patients because aging itself and potential co-morbid disease may also cause functional disability. In this study, we aimed to look at the correlation between disease activity and functional disability in elderly RA patients. Elderly RA patients, ≥65 years old at their routine visits were included in the study. The composite ‘disease activity score’ in 28 joints (DAS-28) was used to determine disease activity groups. Health assessment questionnaire (HAQ) scores were calculated to describe the functional disability and compared across the disease activity groups. Two hundred and fifty-eight RA patients with the mean age of 71 ± 5 (65–90) and a total disease duration of 8.4 ± 8.5 (.5–50) years were recruited. The proportion of patients with high and moderate disease activity was 70%. HAQ scores were significantly correlated with disease activity (p < .05). Functional disability estimated by HAQ was correlated with disease activity in elderly patients with RA     

Gender diversity and motivation in collaborative learning groups: the mediating role of group discussion quality

Collaborative learning is often used in higher education to help students develop their teamwork skills and acquire curricular knowledge. In this paper we test a mediation model in which the quality of group discussions mediates the impact of gender diversity and group motivation on collaborative learning effectiveness. Our results show that the proportion of women in groups, and the group level need for cognition and core self-evaluations (within group average) positively predict discussion quality that in turn predicts group (academic) performance. Our results show that discussion quality fully mediates the effects of need for cognition and core self-evaluations on group performance. The effect for gender diversity on group performance is only partly mediated by discussion quality.     

Peer Rejection and Internalizing Behavior: The Mediating Role of Peer Victimization in Preschool

The author examined the relationship among peer rejection, peer victimization, and internalizing behaviors. The author hypothesized that physical and relational victimization would have a different indirect effect on the relationship between peer rejection and internalizing behaviors. Participants were 94 preschool children (37 girls; average age 49.97 months) from two university preschools located in the northern part of the United States. The results indicated that internalizing behaviors predicted the mediating variables only regarding relational victimization. Relational victimization indirectly affected the association between peer rejection and internalizing behaviors. The study provides evidence of the mediating effect of victimization behaviors on the relationship among peer rejection, victimization, and internalizing behaviors.     

Directional preferences in turning behavior of girls and boys

Turning biases in humans and animals are known to be related to dopaminergic asymmetry between the brain hemispheres. A laboratory method, in which turning preference was evaluated, was adapted based upon the turning of the subject toward a particular sound in a square room. One of the aims of this study was to investigate the reliability of this method with children, and the other aim was to research the turning preference in boys and girls. 31 children between 7 and 13 yr. old volunteered as subjects, and 17 subjects were retested. The subjects tended significantly to turn leftward (60.1%), and fewer girls (53.7%) turned to the left than boys (66.2%). The correlation between the test and the retest was significant (r=.79, p< .01). Most studies have indicated that humans in childhood and adulthood exhibit left-turning preference, but conflicts between the results obtained on different types of rotation tasks have suggested that hemispheric dopaminergic activity might affect preference. That needs study.