Speed-accuracy trade-offs in myocontrol

Myoelectric (EMG) signals are used in assistive technology for prostheses, computer and domestic control. However, little is known about the capacity of controlling these signals. Specifically, it is unclear whether myocontrol, i.e., the control of myoelectric signals, obeys the same laws as motor control. Neurologically intact adult participants performed pointing tasks with EMG signals captured from the forehead or the hand in two modalities (sustained: stabilize the signal amplitude in the target; impulsion: produce an impulse and return to resting level). In the sustained modality, the time to reach the target (reach time) increased logarithmically with target amplitude, which is compatible with the predictions of Fitts' law. The rate of failure was not significantly affected by target amplitude. In the impulsion modality, the reach time and the rate of failure followed a bow-shaped pattern as a function of target amplitude. Stabilization time in the sustained modality followed a convex (bow-shaped) pattern for the forehead and a concave pattern for the hand. This was the only significant effect of electrode placement in this study. These findings suggest that myocontrol obeys laws that are distinct from those determining motor control, and that the muscular and intra-muscular synergies that produce EMG signals are specific of each pointing modality and target amplitude.     

The classification of violence risk

The Classification of Violence Risk (COVR) is an interactive software program designed to estimate the risk that a person hospitalized for mental disorder will be violent to others. The software leads the evaluator through a chart review and a brief interview with the patient. At the end of this interview, the software generates a report that contains a statistically valid estimate of the patient's violence risk-ranging from a 1% to a 76% likelihood of violence-including the confidence interval for that estimate, and a list of the risk factors that the program took into account to produce the estimate. In this article, the development of the COVR software is described and several issues that arise in its administration are discussed.     

Relationships among team ability composition, team mental models, and team performance

This study examined the relationship between the similarity and accuracy of team mental models and compared the extent to which each predicted team performance. The relationship between team ability composition and team mental models was also investigated. Eighty-three dyadic teams worked on a complex skill task in a 2-week training protocol. Results indicated that although similarity and accuracy of team mental models were significantly related, accuracy was a stronger predictor of team performance. In addition, team ability was more strongly related to the accuracy than to the similarity of team mental models and accuracy partially mediated the relationship between team ability and team performance, but similarity did not.     

Large-scale investigation of the role of trait activation theory for understanding assessment center convergent and discriminant validity

This study used trait activation theory as a theoretical framework to conduct a large-scale test of the interactionist explanation of the convergent and discriminant validity findings obtained in assessment centers. Trait activation theory specifies the conditions in which cross-situationally consistent and inconsistent candidate performances are likely to occur. Results obtained by aggregating correlations across 30 multitrait-multimethod matrices supported the propositions of trait activation theory, shedding a more positive light on the construct validity puzzle in assessment centers. Overall, convergence among assessment center ratings was better between exercises that provided an opportunity to observe behavior related to the same trait, and discrimination among ratings within exercises was generally better for dimensions that were not expressions of the same underlying traits. Implications for assessment center research and practice are discussed.     

Preventing Depression Among Early Adolescents in the Primary Care Setting: A Randomized Controlled Study of the Penn Resiliency Program

This study evaluated the Penn Resiliency Program's effectiveness in preventing depression when delivered by therapists in a primary care setting. Two-hundred and seventy-one 11- and 12-year-olds, with elevated depressive symptoms, were randomized to PRP or usual care. Over the 2-year follow-up, PRP improved explanatory style for positive events. PRP's effects on depressive symptoms and explanatory style for negative events were moderated by sex, with girls benefiting more than boys. Stronger effects were seen in high-fidelity groups than low-fidelity groups. PRP did not significantly prevent depressive disorders but significantly prevented depression, anxiety, and adjustment disorders (when combined) among high-symptom participants. Findings are discussed in relation to previous PRP studies and research on the dissemination of psychological interventions. An erratum to this article is available at .     

Testing the attention shift hypothesis as an account for the flanker sequence-based congruency modulation in spatial flanker tasks

Smaller Simon effects when stimulus locations are repeated on successive trials rather than alternated have been explained by the attention shift hypothesis, suggesting that shifts of attention result in interfering response codes. We investigated whether the attention shift hypothesis can also explain smaller flanker effects for repeated flankers than for alternated flankers, which occur only with directional information. In 3 peripheral letter identification tasks, target locations were cued by partial or complete flanker stimuli. Experiments 1 and 2 showed that directional flankers elicit shifts of attention. However, Experiment 3 revealed that directional flankers induced inverted cuing effects when reacting to the central target arrow was additionally required. These results are difficult to reconcile with the attention shift hypothesis as an explanation for the congruency reduction with repetitions of directional flankers.     

The selection of creative ideas after individual idea generation: Choosing between creativity and impact

It is commonly assumed that successful innovation depends on creative idea generation: the more ideas are generated, the higher the probability of selecting a very good idea should be. However, research has shown that people do not perform optimally at idea selection and that ideational output may not contribute much to creative idea selection. The present studies aim to explain this phenomenon. We identified the strong tendency of our participants to select feasible and desirable ideas, at the cost of originality, as the main reason for their poor selection performance. Two manipulations of participants' processing of the available ideas (exclusion instructions and quality ratings) had no effect on selection effectiveness. In contrast, explicitly instructing participants to select creative or original ideas did improve selection effectiveness with regard to idea originality, but at the same time decreased participants' satisfaction and the rated effectiveness of chosen ideas. Results are discussed in relation to an effectiveness‐originality trade off.     

The role of comorbid disruptive behavior in the clinical expression of pediatric obsessive-compulsive disorder

This study explored the impact of disruptive behavior disorder (DBD) comorbidity on a number of theoretically relevant outcomes among 192 children and adolescents with obsessive-compulsive disorder (OCD). Youth were divided into three groups: OCD Only, OCD+DBD comorbidity and OCD+Other comorbidity. Relative to those without a comorbid condition and those with any non-DBD comorbidity, comorbid DBD was associated with greater family accommodation and less symptom resistance. Youth with comorbid DBD exhibited greater OCD symptom severity, OCD-related impairment, anxiety, and internalizing problems than those with no comorbidity. Those with comorbid DBD were over 3.6 times as likely to be taking an atypical antipsychotic medication relative to children without comorbidity. The present results suggest that comorbid DBD contributes to more severe illness presentation above and beyond an OCD diagnosis alone, and may be associated with differing pharmacotherapy prescribing practices.