Motion, not masking, provides the medium for feature attribution

ABSTRACT— Understanding the dynamics of how separate features combine to form holistic object representations is a central problem in visual cognition. Feature attribution (also known as feature transposition and feature inheritance) refers to the later of two stimuli expressing the features belonging to the earlier one. Both visual masking and apparent motion are implicated in feature attribution. We found that when apparent motion occurs without masking, it correlates positively with feature attribution. Moreover, when apparent motion occurs with masking, feature attribution remains positively correlated with apparent motion after the contribution of masking is factored out, but does not correlate with masking after the contribution of apparent motion is similarly factored out. Hence, motion processes on their own provide the effective medium for feature attribution. Our results clarify the dynamics of feature binding in the formation of integral and unitary object representations in human vision.     

Eating disorder pathology among overweight treatment-seeking youth: clinical correlates and cross-sectional risk modeling

Preliminary research suggests that pediatric overweight is associated with increased eating disorder pathology, however, little is known about which overweight youth are most vulnerable to eating disorder pathology. We therefore investigated 122 overweight treatment-seeking youth to describe eating disorder pathology and mental health correlates, and to identify psychopathological constructs that may place overweight youth at increased risk for eating disorder pathology. Youth participated in a comprehensive assessment of eating disorders, mood and anxiety disorders, general psychopathology, and risk variables involving semi-structured clinical interviews and self- and parent-report questionnaires prior to the initiation of weight-loss treatment. Ten youth met criteria for an eating disorder, and over one-third endorsed recent binge eating. Eating disorder pathology was associated with depressive and anxious symptoms (p's<0.001). Structural equation modeling indicated increased negative affect, teasing experience, and thin-ideal internalization, and decreased perfectionism were associated with increased eating disorder pathology. Findings corroborate earlier work indicating that eating disorder pathology is elevated and clinically significant in overweight treatment-seeking youth, bolstering the need for mental health assessment of such individuals. Cross-sectional modeling proposed key variables that relate to eating disorder pathology in overweight treatment-seeking youth, which following prospective replication, may inform the development of effective interventions for overweight and eating disorders.     

Decomposition of variability in the execution of goal-oriented tasks: three components of skill improvement

A central ability of the motor system is to achieve goals with great reliability, although never with zero variability. It is argued that variability is reduced with practice by 3 separate means: reduction of stochastic noise (N), exploitation of task tolerance (T), and covariation (C) between central variables. A method is presented that decomposes variability into these components in relation to task space that is defined by the execution variables. Successful variable combinations form the solution manifold. In a virtual skittles task, it is demonstrated that participants' improvement over repetitions, indicated by increasing accuracy, is accounted for by N, T, and, to a lesser degree, C. The relative contribution of these components changes over the course of practice and task variations.     

History dependence of skeletal muscle force production: implications for movement control

In this study, we review existing evidence on the history dependence of skeletal muscle force production. Specifically, we investigate the steady-state forces following shortening or stretching of an activated skeletal muscle preparation and compare these forces to the corresponding steady-state forces obtained for purely isometric contractions at identical lengths. Force depression following shortening and force enhancement following stretch can reach values of almost 50% of the corresponding isometric reference force, and thus might affect movement control. We also show novel results on history-dependent effects for voluntary contractions in human skeletal muscles, thereby emphasizing that voluntary force production is affected by the contractile history of the target muscles. These results lead to the conclusion that history-dependent force production should be considered in models of movement control and voluntary force production.     

Testing quantitative models of backward masking

We analyzed the relationship between U-shaped and monotonic-shaped masking functions, using both computer simulations of quantitative models and experimental data. Our analysis revealed that quantitative models of backward masking predict that U-shaped masking functions should appear for weak masks and monotonic masking functions should appear for strong masks. The models predict, moreover, that for a fixed target and experimental task, as the mask changes it is possible to go from U-shaped to monotonic-shaped masking functions. Significantly, the models predict that at each stimulus onset asynchrony between the target and the mask, the U-shaped function must have weaker masking than the monotonic-shaped function. Contrary to the predictions of the models, we show an experimental situation that generates masking functions that violate this prediction.     

Pretreatment task persistence predicts smoking cessation outcome

R. Eisenberger's (1992) learned industriousness theory states that individuals display differing degrees of persistence depending on their history of reinforcement for effortful behavior. These differences may influence the development, maintenance, and cessation of addictive behaviors. In cross-sectional studies, E. P. Quinn, T. H. Brandon, and A. L. Copeland (1996) found that cigarette smokers were less persistent than nonsmokers, and R. A. Brown, C. W. Lejuez, C. W. Kahler, and D. R. Strong (2002) found that smokers who had previously abstained for 3 months were more persistent than those who had never quit. The present study extended these findings by using a prospective design. A pretreatment measure of task persistence (mirror tracing) completed by 144 smokers predicted sustained abstinence throughout 12 months of follow-up. Moreover, persistence predicted outcome independent of other significant predictors: gender, nicotine dependence, negative affect, and self-efficacy.     

Elternschaft, Krebs und Kindersorgen

Background

The diagnosis of parental cancer may destabilize the whole family, parents and children as well. The Hamburg children of somatically ill parents (COSIP) intervention supports parental skills and adaptation of children to the situation. There is currently no evidence for criteria to determine which family members should be involved in the COSIP intervention, predominantly the parents (parent setting), the children (child setting) or both (family setting).

Aim of the study

Data from a multicentre study were analyzed with respect to the predominant intervention settings, the correlation between setting and aims of intervention as well as variables that predict the involvement of children in the intervention.

Material and methods

A total of 203 documented cases were analyzed. Different variables that had been documented by the therapists were included in a regression analysis model in order to identify predictive variables.

Results

In 142 cases the intervention was carried out in a specific intervention setting. In 57?% of the cases children were involved (32?% family setting and 25?% child setting). A systematic relationship between the reported intervention aims and the intervention setting was not detected. The most powerful predictor was the existence of emotional problems of children as reported by the child itself.

Conclusions

Decision-making on intervention settings should therefore take the assessment of emotional symptoms of children by the means of age-appropriate self-reporting tools into consideration. Further investigations are needed to reveal variables concerning needs, motivation and capabilities of the family members as well as institutional conditions.