Hostile attributional bias and aggressive behavior in global context

We tested a model that children’s tendency to attribute hostile intent to others in response to provocation is a key psychological process that statistically accounts for individual differences in reactive aggressive behavior and that this mechanism contributes to global group differences in children’s chronic aggressive behavior problems. Participants were 1,299 children (mean age at year 1 = 8.3 y; 51% girls) from 12 diverse ecological-context groups in nine countries worldwide, followed across 4 y. In year 3, each child was presented with each of 10 hypothetical vignettes depicting an ambiguous provocation toward the child and was asked to attribute the likely intent of the provocateur (coded as benign or hostile) and to predict his or her own behavioral response (coded as nonaggression or reactive aggression). Mothers and children independently rated the child’s chronic aggressive behavior problems in years 2, 3, and 4. In every ecological group, in those situations in which a child attributed hostile intent to a peer, that child was more likely to report that he or she would respond with reactive aggression than in situations when that same child attributed benign intent. Across children, hostile attributional bias scores predicted higher mother- and child-rated chronic aggressive behavior problems, even controlling for prior aggression. Ecological group differences in the tendency for children to attribute hostile intent statistically accounted for a significant portion of group differences in chronic aggressive behavior problems. The findings suggest a psychological mechanism for group differences in aggressive behavior and point to potential interventions to reduce aggressive behavior.Why do children in some ecological contexts and cultural groups across the world exhibit more chronic aggressive behavior problems than children in other contexts? We assert that groups differentially socialize a key psychological process of attribution of hostile intent, which mediates the display of aggression in response to threat (i.e., it statistically accounts for differences in reactive aggressive behavior), which, when repeated in interpersonal interactions over time, grows into chronic aggressive behavior problems.Some evolutionary theorists posit the adaptive function of deescalating aggressive conflict in response to ambiguous provocation or threat. Axelrod’s computer simulations and empirical tests of ambiguous conflicts in political science suggest (but do not prove) that the response strategy responsible for the containment of violence and the evolution of cooperation is a “tit for tat” tactic characterized by a benign interpretation of another’s ambiguous intentions (1). He asserts that an alternate two-step strategy of attributing hostile intent to another and retaliating with aggression leads to escalation of conflict and eventual mutual destruction.Despite Axelrod’s assertions that the long-term adaptiveness of reactive aggression is poor, certain ecological contexts have been found to encourage hostile attributions and reactive aggression in response to ambiguous provocations. For example, rhesus macaque mothers who hold high dominance ranks socialize their 9-mo-old infants to display a pattern of high vigilance to threatening faces, probably as a short-term adaptive strategy to enable the offspring to maintain high rank (2). In the US South, a unique “culture of honor” promotes vigilance toward provocateurs, perceptual readiness to attribute hostile intent to others, and retaliatory aggression in response to being dishonored (3). Qualitative accounts of urban violence among minority males also point toward the importance of retaliating against being “dissed,” as in disrespected (4). Recent “Stand Your Ground” laws in the United States excuse retaliation against a perceived provocateur.A pattern of hypervigilance to threat, hostile attribution of intent, and reactive aggression in response to provocation often comes at a cost to an individual within a society and to that society’s long-term health and well-being. A large body of psychological research in the United States indicates that, when an individual attributes hostile intent to a peer provocateur, the individual is likely to become anxious and escalate reactive aggression, leading in turn to chronic aggressive behavior problems (5). Children who consistently make hostile attributions about others have been shown to escalate aggression in response to provocation, to become chronically anxious, and to increase their aggressive behavior problems over time and grow into violent adults (6).How do we reconcile the universality of Axelrod’s tit for tat pattern of benign attributions and cooperation with known ecological group differences in chronic aggressive behavior rates? A social ecological model that embeds behavior in a widening circle of ecological contexts (e.g., family, community, culture) posits that a child’s cultural-ecological context of local norms, values, and affordances will influence that child’s attention and attribution processes, which, in turn, will account for that child’s aggressive behavior (ecological context → child hostile attribution bias → child aggression) (7). We assert that some environments socialize a pattern that consists of high vigilance to threat, hostile attributions of another’s intent, and reactive aggression. The reasons for group differences in socialization patterns are beyond the scope of this study but likely grow in response to local environmental challenges such as genuine threat from outside groups, political conflict, and relative economic disadvantage, and are perpetuated through transmission across generations.We propose a model of hostile attributional bias, depicted in Fig. 1, which builds on these ideas. We posit that Axelrod’s universal axiom that the psychological act of making a benign attribution about another’s provocation leads to the deescalation of conflict (and, reciprocally, that a hostile attribution leads to reactive aggression). We hypothesize that variation in a child’s reactive aggressive behaviors across the situations that a child experiences will co-occur within that child with the attribution of hostile intent toward a provocateur. We further hypothesize that individual differences across children in reactive aggression in response to provocation will be accounted for partially by individual differences across children in the tendency to make hostile attributions and that both hostile attributional biases and reactive aggressive responses to provocation will predict present and future individual differences in chronic aggressive behavior problems even controlling for prior individual differences in chronic aggression.Open in a separate windowFig. 1.Hypothesized model of how ecological context affects chronic aggressive behavior by influencing hostile attributional biases.Finally, and most importantly, we assert that ecological group differences in rates of chronic aggressive behavior problems are due in part to culturally socialized differences in how children are reared to become vigilant toward threat and to make hostile attributions about others under conditions of ambiguous provocation. If this model is supported, it suggests interventions to reduce a group’s rate of chronic aggressive problems, and it has implications for understanding some cross-group conflicts (e.g., Arab-Israeli conflict and racial conflict within the United States), which could be understood as a function of group differences in how attributions of outgroup intentions are socialized and used to justify cross-group violence. Study of antecedents of cross-group conflict is beyond the present scope and is not pursued further here.To test the tenets of this model, we used identical methods with large samples of children followed prospectively across diverse ecological socializing contexts around the world. The goal of the current study was to test three sets of hypotheses in a sample of 8-y-old boys and girls from 12 different groups around the world followed annually over 4 y.The first hypothesis (the within-child hypothesis) is that variation in reactive aggressive behavior in response to provocation situations within a child will be statistically accounted for by variation in the attributions that child makes across peer provocation situations. We hypothesize that this relation will hold universally in each ecological context and in each sex.The second hypothesis (the between-children hypothesis) asserts that measurements of a child’s attributions about peers’ intentions will yield internally consistent individual differences across children, called hostile attributional bias, which acts like an acquired personality trait to correlate with and predict chronic aggressive behavior. We hypothesize that variation across children in hostile attributional bias will be correlated with children’s chronic tendencies to assert that they would react aggressively in response to a provocation; furthermore, we hypothesize that children’s hostile attributional biases will predict their current and future chronic aggressive behavior problems as measured by themselves and their mothers even controlling for prior aggressive behavior problems, and these relations will hold in each ecological context and each sex.The third hypothesis (the between-context hypothesis) asserts that ecological-cultural group differences in children’s rates of mother-rated and self-rated chronic aggressive behavior problems will be partially statistically accounted for by group differences in children’s hostile attributional biases and self-predicted tendencies to react aggressively in response to ambiguous threat.     

Sodium Hypochlorite and a Preparation Containing Glycocholic Acid and Surfactants Have a Synergistic Action on Organic Tissue Dissolution In Vitro

Introduction

The aim of this study was to evaluate porcine palatal mucosa dissolution by sodium hypochlorite (NaOCl) with or without an auxiliary dissolving agent containing glycocholic acid and a mixture of surfactants (Keratobacter [KB]; Saint Joseph DID, Valencia, Spain).

Image quality of mammography in Croatian nationwide screening program: comparison between various types of facilities

Purpose

The study was aimed to provide objective evidence about the mammographic image quality in Croatia, to compare it between different types of MG facilities and to identify the most common deficiencies and possible reasons as well as the steps needed to improve image quality.

Materials and methods

A total of 420 mammographic examinations collected from 84 mammographic units participating in the Croatian nationwide breast cancer screening program were reviewed in terms of four image quality categories: identification of patient and examination, breast positioning and compression, exposure and contrast, and artifacts. Those were rated using image evaluating system based on American College of Radiology and European Commission proposals. The results were compared among different types of mammographic units, and common image quality deficiencies were identified.

Results

Total image quality scores of 12.8, 16.1, 13.0 and 13.7 were found for general hospitals, university hospitals, private clinics and public healthcare centres, respectively. Average score for all mammographic units was 13.5 (out of 25 points). University hospitals were significantly better than all other mammography units in overall image quality, which was mostly contributed by better breast positioning practices. Private clinics showed the worst results in identification, exposure, contrast and artifacts.

Conclusions

Serious deficiencies in identification and breast positioning, which might compromise breast cancer screening outcome, were detected in our material. They occur mainly due to subjective reasons and could be corrected through additional staff training and improvement of working discipline.     

The effect of a gadolinium-based contrast agent on diffusion tensor imaging

Objective

The aim of this study was to investigate in detail the effect of gadolinium contrast on diffusion tensor imaging scans. As the present literature offers conflicting results, we have included a large selection of indices in the analysis.

Materials and methods

Sixteen patients harboring an intra-axial contrast enhancing brain tumor were included in this study. Two diffusion tensor imaging scans were performed—one natively, and the second following a gadolinium contrast agent application. Maps of the invariant indices fractional anisotropy (FA), linear, planar, and spherical indices, trace, eigenvalues λ₁, λ₂, λ₃ as well as of the components of the diffusion tensor matrix Dxx, Dyy, Dzz, Dxy, Dxz and Dyz were co-registered and compared statistically with matching ROI pairs in the contrast enhancing areas, peritumoral edema and the normal appearing white matter.

Results

We have observed a significant increase in the FA and disproportional decrease of the eigenvalues in the post-contrast scans. In accordance with these findings, the spherical index was decreased and the linear and planar indices were increased. There was a significant decrease of all diagonal components of the diffusion tensor matrix. These changes have been strongest in the contrast enhancing areas, but there were also significant changes in the peritumoral edema and the normal appearing white matter.

Conclusion

Diffusion tensor imaging scans performed after gadolinium contrast agent administration may display artificially increased FA values due to disproportional changes of the measured eigenvalues. The distortion of the diffusion measurement is strongest in, but not limited to the contrasting areas.     

On multiple alternating steady states induced by periodic spin phase perturbation waveforms

Direct measurement of neural currents by means of MRI can potentially open a high temporal resolution (10–100 ms) window applicable for monitoring dynamics of neuronal activity without loss of the high spatial resolution afforded by MRI. Previously, we have shown that the alternating balanced steady state imaging affords high sensitivity to weak periodic currents owing to its amplification of periodic spin phase perturbations. This technique, however, requires precise synchronization of such perturbations to the radiofrequency pulses. Herein, we extend alternating balanced steady state imaging to multiple balanced alternating steady states for estimation of neural current waveforms. Simulations and phantom experiments show that the off‐resonance profile of the multiple alternating steady state signal carries information about the frequency content of driving waveforms. In addition, the method is less sensitive than alternating balanced steady state to precise waveform timing relative to radiofrequency pulses. Thus, multiple alternating steady state technique is potentially applicable to MR imaging of the waveforms of periodic neuronal activity. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.     

Adipose stromal vascular fraction improves cardiac function in chronic myocardial infarction through differentiation and paracrine activity

Fresh adipose-derived cells have been shown to be effective in the treatment of acute myocardial infarction (MI), but their role in the chronic setting is unknown. We sought to determine the long-term effect of the adipose derived-stromal vascular fraction (SVF) cell transplantation in a rat model of chronic MI. MI was induced in 82 rats by permanent coronary artery ligation and 5 weeks later rats were allocated to receive an intramyocardial injection of 10(7) GFP-expressing fresh SVF cells or culture media as control. Heart function and tissue metabolism were determined by echocardiography and (18)F-FDG-microPET, respectively, and histological studies were performed for up to 3 months after transplantation. SVF induced a statistically significant long-lasting (3 months) improvement in cardiac function and tissue metabolism that was associated with increased revascularization and positive heart remodeling, with a significantly smaller infarct size, thicker infarct wall, lower scar fibrosis, and lower cardiac hypertrophy. Importantly, injected cells engrafted and were detected in the treated hearts for at least 3 months, directly contributing to the vasculature and myofibroblasts and at negligible levels to cardiomyocytes. Furthermore, SVF release of angiogenic (VEGF and HGF) and proinflammatory (MCP-1) cytokines, as well as TIMP1 and TIMP4, was demonstrated in vitro and in vivo, strongly suggesting that they have a trophic effect. These results show the potential of SVF to contribute to the regeneration of ischemic tissue and to provide a long-term functional benefit in a rat model of chronic MI, by both direct and indirect mechanisms.