Spatial reconstruction of human motion by means of a single camera and a biomechanical model

The value of the results of the inverse dynamic analysis procedures used in the study of human tasks is dependent on the quality of the kinematic and kinetic data supplied to the biomechanical model that supports it. The kinematic data, containing the position, velocity and acceleration of all anatomical segments of the biomechanical model, result from the reconstruction of human spatial motion by means of the evaluation of the anatomic points positions that enable to uniquely define the position of all anatomical segments. Furthermore, the motion data must be kinematically consistent with the structure of the biomechanical model used in the analysis. The traditional photogrammetric methodologies used for the spatial reconstruction of the human motion require images of two or more calibrated and synchronized cameras. This is due to the fact that the projection of each anatomical point is described by two linear equations relating its three spatial coordinates with the two coordinates of the projected point. The need for the image of another camera arises from the fact that a third equation is necessary to find the original spatial position of the anatomical point. The methodology proposed here substitutes the projection equations of the second camera with the kinematic constraint equations associated with a biomechanical model in the motion reconstruction process. In the formulation the system of equations arising from the point projections and biomechanical model kinematic constraints, representing the constant length of the anatomical segments, are solved simultaneously. Because the system of equations has multiple solutions for each image, a strategy based on the minimization of a cost function associated to the smoothness of the reconstructed motion is devised. It is shown how the process is implemented computationally avoiding any operator intervention during the motion reconstruction for a given time period. This leads to an automated computer procedure that ensures the uniqueness of the reconstructed motion. The result of the reconstruction process is a set of data that is kinematically consistent with the biomechanical model used. Through applications of the proposed methodology to several sports exercises its benefits and shortcomings are discussed.     

Do violent video games impair the effectiveness of in-game advertisements? The impact of gaming environment on brand recall, brand attitude, and purchase intention

The present study examined whether a violent video game impairs the effectiveness of in-game advertisements compared to a nonviolent video game. Participants recalled and evaluated in-game ads after navigating identical violent or nonviolent game scenarios. Participants' brand recall, recognition, and attitudes were comparatively lower after navigating the violent video game. Also, females in the violent game condition reported lower brand attitudes in comparison to males in the violent game condition, thus suggesting that the effects of gaming environment interacts with participants' gender. The findings supported the predictions of the limited capacity model of attention and cognitive priming effects. The results also extend previous studies on how violent media impair advertising effectiveness and provide practical implications for researchers and practitioners.     

Hemispheric asymmetry in recognition memory: effects of retention level on the recognition of Portuguese words

Early findings from Broca and Wernicke led to the classical view of hemispheric specialization, where the main idea relates to left-hemisphere language capabilities compared to right-hemisphere visual capabilities. Federmeier and Benjamin (2005) have suggested that semantic encoding for verbal information in the right hemisphere can be more effective when memory demands are higher. In light of this, our main goal was to study the effect of retention level of verbal information on hemispheric processes. However, regarding the cross-linguistic differences in orthography and their subsequent effects on word recognition (Frost, Katz, & Bentin, 1987), our intent was also to test prior predictions of Federmeier and Benjamin (2005) for a "shallow" orthography language, where words have a clear correspondence between graphemes and phonemes, as opposed to English, which is a "deep" orthography language. Portuguese concrete nouns were selected. The participants were submitted to a visual half-field word presentation using a continuous recognition memory paradigm. The retention level included 1, 2, 4, 8, 20 or 40 words. Results showed that recognition accuracy was higher for words studied in the right visual field, compared to those studied in the left visual field, when the retention interval included 2, 4, or 20 words. No significant differences were found for the remaining intervals. Further analysis on accuracy data for intermediate retention levels showed that recognition accuracy was higher for the 2 words retention level than for the levels including 4, 8, or 20 words; it was higher for left-hemisphere encoding as well. Our results also indicated that reaction times were slower for left-hemisphere encoding and for the 40 words retention level when compared to that of 20 words. In summary, the current results are in partial agreement with those of Federmeier and Benjamin (2005) and suggest different hemispheric memory strategies for the semantic encoding of verbal information.     

Ethical Dilemmas in Genetic Testing: Examples from the Cuban Program for Predictive Diagnosis of Hereditary Ataxias

Predictive testing protocols are intended to help patients affected with hereditary conditions understand their condition and make informed reproductive choices. However, predictive protocols may expose clinicians and patients to ethical dilemmas that interfere with genetic counseling and the decision making process. This paper describes ethical dilemmas in a series of five cases involving predictive testing for hereditary ataxias in Cuba. The examples herein present evidence of the deeply controversial situations faced by both individuals at risk and professionals in charge of these predictive studies, suggesting a need for expanded guidelines to address such complexities.     

Autopoiesis and Darwinism

The purpose of this paper is to offer a critical approach to the theory of autopoiesis in order to see how it challenges mainstream Darwinism. In the first part of the paper, I characterize Darwinism from the concepts of natural selection, heredity, reproduction, and evolution. This characterization is absolutely schematic, and I hope not controversial at all, since my aim is to provide a general background for the discussion of the rest of the paper. The second part presents the main tenets of the theory of autopoiesis, also paying special attention to the concepts of natural selection, heredity, reproduction, and evolution. The third and final part considers some criticisms that have been directed against the theory and suggests some new ones. As I said, my intention is to offer a critical approach, so that I pretend to assess neither autopoiesis nor Darwinism. The assessment, it seems to me, would be a matter of scientific debate—not properly of philosophy. Therefore, given that my approach attempts to be a conceptual clarification, my contribution to the contemporary debate about Darwinism is twofold. On the one hand, I show that conceptually autopoiesis constitutes an important challenge to Darwinism, but on the other, I also show that some fundamental aspects of the theory appear to be both epistemologically and empirically problematic, which perhaps helps to understand why autopoiesis is not widely accepted in mainstream Darwinism.     

Intergroup time bias and racialized social relations

Within the framework of intergroup relations, the authors analyzed the time people spent evaluating ingroup and outgroup members. They hypothesized that White participants take longer to evaluate White targets than Black targets. In four experiments, White participants were slower to form impressions of White than of Black people; that is, they showed an intergroup time bias (ITB). In Study 1 (N = 60), the ITB correlated with implicit prejudice and homogeneity. Study 2 (N = 60) showed that the ITB was independent of the type of trait in question (nonstereotypical vs. stereotypical). Study 3 (N = 100) demonstrated that ITB correlates with racism measured 3 months beforehand, is independent of motivation to control prejudice, and is not an epiphenomenon of homogeneity. In Study 4 (N = 40) participants not only showed the ITB in a racialized social context but also displayed it following a minimal group manipulation.     

The learning and motor development transfer process

The aim of this study is to analyze the transference process in motor skill learning. For this purpose, 320 boys and girls, with ages ranging from 3 to 12 years (M= 7.61; SD= 2.61), took part in nine object movement reception drills in which the following variables were cross-examined: the presence-absence of displacement (static or in motion), the corporal segments utilized (hands or arms), the movement direction (right or left), and the moving object (volleyball or tennis ball). The results indicate that what is being transferred is the common factor among them, the ocular-kinesthetic regulating system, which is constructed according to a generalized motor program and a predictive strategy of continuous control. The way that individuals group by levels of skill that represent the developmental levels of the aforementioned regulating system can also be observed. Lastly, the results are discussed, and strategies to improve the learning process in sports and physical education are provided.     

Cultural inertia: The effects of cultural change on intergroup relations and the self-concept

Throughout the world, immigration and the ensuing political reactions have become dominant social problems in the 21st century. One contributor to these problems includes the continual social change. In the United States, ethnic minority populations are growing while the White majority is becoming proportionally smaller. It is proposed that change, in and of itself, can produce intergroup tension. Here, the concept of cultural inertia is introduced as one contributor to intergroup prejudice. Cultural inertia entails a resistance to change, unless change is already occurring. Change is perceived differently across groups as a function of how well the groups already match the current dominant culture. Cultural inertia causes differential preferences for cultural change as a function of the extent to which people identify with a cultural group, their sense of esteem for a cultural group, and the perception that a culture is (or is not) already changing. Three studies manipulated participants' perception of cultural change and show that cultural change influences inter-group prejudice, group esteem, and engagement with the culture. The implications of cultural inertia for models of intercultural ideologies are discussed.     

What counts as evidence for working memory training? Problems with correlated gains and dichotomization

The question of whether computerized cognitive training leads to generalized improvements of intellectual abilities has been a popular, yet contentious, topic within both the psychological and neurocognitive literatures. Evidence for the effective transfer of cognitive training to nontrained measures of cognitive abilities is mixed, with some studies showing apparent successful transfer, while others have failed to obtain this effect. At the same time, several authors have made claims about both successful and unsuccessful transfer effects on the basis of a form of responder analysis, an analysis technique that shows that those who gain the most on training show the greatest gains on transfer tasks. Through a series of Monte Carlo experiments and mathematical analyses, we demonstrate that the apparent transfer effects observed through responder analysis are illusory and are independent of the effectiveness of cognitive training. We argue that responder analysis can be used neither to support nor to refute hypotheses related to whether cognitive training is a useful intervention to obtain generalized cognitive benefits. We end by discussing several proposed alternative analysis techniques that incorporate training gain scores and argue that none of these methods are appropriate for testing hypotheses regarding the effectiveness of cognitive training.     

EFFECTS OF AN INDEPENDENT GROUP CONTINGENCY SPECIAL ACTIVITY PROGRAM ON INAPPROPRIATE BEHAVIOR IN A RESIDENTIAL SETTING

Group contingencies targeting inappropriate behavior may be especially useful in residential settings where the staff to client ratio makes individualized behavior plan implementation difficult. The purpose of the current study was to evaluate an independent group contingency on inappropriate behavior in a secure residential facility for offenders with disabilities. The independent group contingency involved differential reinforcement of low rate and differential reinforcement of other behavior via access to a special activity (a catered weekly lunch). The group contingency was alternated with non‐activity weeks for a total of 48 weeks. Results were analyzed across and within residents and showed lower overall rates of inappropriate behavior on activity weeks than non‐activity weeks for the majority of residents. Copyright © 2014 John Wiley & Sons, Ltd.