Aggression is suppressed by acute stress but induced by chronic stress: Immobilization effects on aggression, hormones, and cortical 5-HT1B/ striatal dopamine D2 receptor density

Although it has been established by a number of investigators that a variety of stressors are associated with the induction of aggressive behavior, two specific issues remain unanswered. First, it is unclear whether the contexts surrounding stressors (e.g., stressor length and chance of winning over opponents) change outcomes regarding aggressive behavior. Second, if a relationship exists between stress and aggressive behavior, altered levels of stress-related hormone (e.g., corticosterone [CORT]), as well as aggression-related biomarkers (e.g., testosterone [T], density of prefronto-cortical 5-HT(1B) receptor and striatal dopamine D(2) receptor [D2r]) may contribute to changes in aggressive behavior. Thus, we examined how immobilization (with a 1-, 5-, or 10-day exposure) would impact (1) a longitudinal course of aggression toward different-sized opponents, (2) levels of CORT and T, and (3) densities of 5-HT(1B) receptor (5-HT1Br) in the prefrontal cortex (PFC) and D2r in the striatum. It was found that, regardless of small or large opponents, a single 2-h exposure to immobilization reduced aggressive behavior (stress-suppressed aggression) over time, whereas repeated (10-day) exposure to immobilization escalated aggressive behavior (stress-induced aggression). These stress effects persisted up to 1 week of recovery from immobilization stress. Moreover, immobilized rats demonstrated elevated levels of T, but not CORT, as compared with controls. Finally, acute immobilization altered D2r densities in the shell of the nucleus accumbens, and chronic immobilization changed 5-HT1Br in the PFC, including the downregulation of 5-HT1Br densities in the right prelimbic and orbitolateral cortices. The potential relationships among stress, aggression, and 5-HT1Br/D2r roles are discussed.     

The persuasive “power” of stigma?

We predicted that able-bodied individuals and White Americans would have a difficult time saying no to persuasive appeals offered by disabled individuals and Black Americans, due to their desire to make such interactions proceed smoothly. In two experiments, we show that members of stigmatized groups have a peculiar kind of persuasive “power” in face-to-face interactions with non-stigmatized individuals. In Experiment 1, wheelchair-bound confederates were more effective in publicly soliciting donations to a range of charities than confederates seated in a regular chair. In Experiment 2, Whites changed their private attitudes more following face-to-face appeals from Black than White confederates, an effect mediated by their increased efforts to appear agreeable by nodding and expressing agreement. This difference was eliminated when impression management concerns were minimized – when participants viewed the appeals on video.     

Heart attack risk perception biases among hypertension patients: the role of educational level and worry

Risk biases such as comparative optimism (thinking one is better off than similar others) and risk inaccuracy (misestimating one's risk compared to one's calculated risk) for health outcomes are common. Little research has investigated racial or socioeconomic differences in these risk biases. Results from a survey of individuals with poorly controlled hypertension (N=813) indicated that participants showed (1) comparative optimism for heart attack risk by underestimating their heart attack risk compared to similar others, and (2) risk inaccuracy by overestimating their heart attack risk compared to their calculated heart attack risk. More highly educated participants were more comparatively optimistic because they rated their personal risk as lower; education was not related to risk inaccuracy. Neither race nor the federal poverty level was related to risk biases. Worry partially mediated the relationship between education and personal risk. Results are discussed as they relate to the existing literature on risk perception.     

The Expectancy Challenge Alcohol Literacy Curriculum (ECALC): A single session group intervention to reduce alcohol use

The Expectancy Challenge Alcohol Literacy Curriculum (ECALC) is a single session group-delivered program designed to modify alcohol expectancy processes and reduce alcohol use among children and young adults. The objective of this study was to demonstrate the effectiveness of the ECALC in reducing risky alcohol use among heavy drinking college men. Four fraternities at a large state university were randomly assigned to receive either the single session ECALC or a control presentation (2 fraternity houses per condition, n = 250). Alcohol expectancies were assessed before and immediately after program presentation. Results demonstrated significant changes on 5 of the 7 subscales of the Comprehensive Effects of Alcohol Scale (CEOA) among students who received the ECALC when compared with control participants. Alcohol use data were collected for 4 weeks before and 4 weeks after program presentation. Compared with those in the control condition, students who received the ECALC demonstrated significant reductions in all facets of alcohol use measured, including decreased mean and peak blood alcohol content (BAC), decreased mean number of days drinking per week, decreased mean drinks per sitting, and decreased number of binge-drinking episodes per month. This study represents 2 important advances. First is the significant reduction in risky alcohol use produced by a single session group-delivered program. The second important advance is the success in changing expectancy processes without using impractical elements common in previous expectancy challenge methods (e.g., a "barlab" environment and actual alcohol administration). (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

From alpha to omega: A practical solution to the pervasive problem of internal consistency estimation

Coefficient alpha is the most popular measure of reliability (and certainly of internal consistency reliability) reported in psychological research. This is noteworthy given the numerous deficiencies of coefficient alpha documented in the psychometric literature. This mismatch between theory and practice appears to arise partly because users of psychological scales are unfamiliar with the psychometric literature on coefficient alpha and partly because alternatives to alpha are not widely known. We present a brief review of the psychometric literature on coefficient alpha, followed by a practical alternative in the form of coefficient omega. To facilitate the shift from alpha to omega, we also present a brief guide to the calculation of point and interval estimates of omega using a free, open source software environment.     

Enculturation to musical pitch structure in young children: evidence from behavioral and electrophysiological methods

Children learn the structure of the music of their culture similarly to how they learn the language to which they are exposed in their daily environment. Furthermore, as with language, children acquire this musical knowledge without formal instruction. Two critical aspects of musical pitch structure in Western tonal music are key membership (understanding which notes belong in a key and which do not) and harmony (understanding which notes combine to form chords and which notes and chords tend to follow others). The early developmental trajectory of the acquisition of this knowledge remains unclear, in part because of the difficulty of testing young children. In two experiments, we investigated 4‐ and 5‐year‐olds' enculturation to Western musical pitch using a novel age‐appropriate and engaging behavioral task (Experiment 1) and electroencephalography (EEG; Experiment 2). In Experiment 1 we found behavioral evidence that 5‐year‐olds were sensitive to key membership but not to harmony, and no evidence that 4‐year‐olds were sensitive to either. However, in Experiment 2 we found neurophysiological evidence that 4‐year‐olds were sensitive to both key membership and harmony. Our results suggest that musical enculturation has a long developmental trajectory, and that children may have some knowledge of key membership and harmony before that knowledge can be expressed through explicit behavioral judgments.     

Short-Term Violent Video Game Play by Adolescents Alters Prefrontal Activity During Cognitive Inhibition

Prior research has indicated an association between exposure to violent media and aggressive thoughts, feelings, and behavior, potentially as a result of effects on inhibitory mechanisms. However, the role of violence in video games in modulating subsequent neural activity related to cognitive inhibition has received little attention. To examine short-term effects of playing a violent video game, 45 adolescents were randomly assigned to play either a violent or a nonviolent video game for 30 minutes immediately prior to functional magnetic resonance imaging (fMRI). During the fMRI procedure, participants performed a go/no-go task that required them to press a button for each target stimulus and withhold the response for non-target stimuli. Participants who played the violent game demonstrated a lower BOLD response in right dorsolateral prefrontal cortex (DLPFC) when responses were appropriately inhibited. The DLPFC is involved with executive functioning, including suppression of unwanted thoughts and behaviors. In addition, responses in the DLPFC demonstrated stronger inverse connectivity with precuneus in the nonviolent game players. These results provide evidence that playing a violent video game can modulate prefrontal activity during cognitive inhibition.     

A randomized wait-list controlled pilot study of dialectical behaviour therapy guided self-help for binge eating disorder

This study examined the efficacy of guided self-help based on dialectical behaviour therapy (DBTgsh) for binge eating disorder (BED). Individuals (88.3% female; mean 42.8 years) were randomized to DBTgsh (n = 30) or wait-list (WL; n = 30). DBTgsh participants received an orientation, DBT manual, and six 20-min support calls over 13 weeks. All participants were assessed pre- and post-treatment using interview and self-report; also, DBTgsh participants were re-assessed six months post-treatment. At treatment end, DBTgsh participants reported significantly fewer past-month binge eating episodes than WL participants (6.0 versus 14.4) and significantly greater rates of abstinence from binge eating (40.0% versus 3.3%). At six-month follow-up, DBTgsh participants reported significantly improved quality of life and reduced ED psychopathology compared to baseline scores. In addition, most improvements in the DBTgsh group were maintained, although binge eating abstinence rates decreased to 30%. These preliminary positive findings indicate that DBTgsh may offer an effective, low-intensity treatment option for BED.     

A Social Exchange Model of Employee Reactions to Electronic Performance Monitoring

The primary goal of this study was to develop and test a social exchange model of employee reactions to electronic performance monitoring (EPM) to help managers use EPM more effectively. This study proposed that certain EPM practices are related to perceptions of interpersonal and informational justice, which in turn build trust in the manager, along with other important attitudes and outcomes. In a sample of 257 call center representatives, the purpose for using EPM, development versus control, was associated with interpersonal justice perceptions, but EPM-based feedback characteristics, whether the feedback was timely, specific, and constructive, were not. Furthermore, the presence of an explanation for EPM was positively related to perceptions of informational justice. Moreover, interpersonal and informational justice perceptions were positively related to trust in the manager, which in turn was positively related to job performance and job satisfaction.     

Psychological Model of Military Aggressive Behavior: Findings From Population-Based Surveys

The U.S. military has expressed concern about the influence of deployment and combat exposure on the criminal behavior of personnel returning from Iraq and Afghanistan. This study examines the role of behavioral health risk and protective factors associated with combat exposure and criminal and aggressive behavior in active duty Army and Naval personnel. Data from this cross-sectional study are based on two large anonymous, population-based health-related behavior surveys. Findings show that the proportion of all active duty Army and Naval service personnel who reported encounters with law enforcement or committed one or more aggressive acts in the past year increased from 19.41% in 2005 to 22.58% in 2008. Substance use, especially illicit drug use, and mental health problems were significant correlates of criminal and aggressive behavior, as were younger age, male sex, high impulsivity, and work/family stress. Path modeling suggested that several variables, notably combat exposure and history of childhood abuse, appeared to manifest their influence on criminal or aggressive behavior through increases in substance use and mental health problems. The potential mediating influence of substance use and mental health on combat and other trauma experiences has significant implications for preventing criminal and aggressive behavior among U.S. active duty military personnel.