Development of the Social Behavior of Two Mice Species With Contrasting Social Systems

The house mouse (Mus musculus) and the mound‐building mouse (M. spicilegus) differ in their mating and social systems. The M. musculus is polygynous and females tend to breed cooperatively while M. spicilegus is known to be monogamous and famous for its unique cooperative behavior; the communal overwintering. Mus spicilegus is considered as a highly aggressive species in the genus Mus. In the present study, we attempted to analyze the development of aggressive and sociable behavior in these species and to discover how familiarity with the target moderates the development of sociable and aggressive behaviors and moderates the differences between the species. Dyadic social interaction tests in neutral cages were performed on 21‐, 60‐, and 120‐day‐old mice of both genders and both species. Each individual was tested against a sibling and an unfamiliar individual at all three ages. Our results showed that the development of aggressive and sociable behavior with age differed between the species and sexes; however, familiarity with the other mouse moderated the effect of species on aggression. At 21 days, both genders of M. spicilegus were more aggressive against strangers than siblings. This became true of both species at 60 days. When facing a stranger, both sexes of M. spicilegus were more aggressive than M. musculus at 120 days. However, when facing a sibling, neither gender of M. spicilegus was more agonistic than M. musculus, indicating that either kinship or early social experiences elicit tolerance. Aggr. Behav. 38:288‐297, 2012. © 2012 Wiley Periodicals, Inc.     

Belief in a just world, teacher justice, and bullying behavior

The relation between school students' belief in a just world (BJW) and their bullying behavior was investigated in a questionnaire study. The mediating role of teacher justice was also examined. Data were obtained from a total of N = 458 German and Indian high school students. Regression analyses revealed that the more strongly students believed in a personal just world and the more they evaluated their teachers' behavior toward them personally to be just, the less bullying behavior they reported. Moreover, students with a strong BJW tended to evaluate their teachers' behavior toward them personally to be more just, and the experience of teacher justice mediated the relation between BJW and less bullying perpetration. This pattern of results was as expected and consistent across different cultural contexts. It persisted when neuroticism, sex, and country were controlled. The adaptive functions of BJW and implications for future school research are discussed.     

Time- and space-order effects in timed discrimination of brightness and size of paired visual stimuli

Despite the importance of both response probability and response time for testing models of choice, there is a dearth of chronometric studies examining systematic asymmetries that occur over time- and space-orders in the method of paired comparisons. In this study, systematic asymmetries in discriminating the magnitude of paired visual stimuli are examined by way of log odds ratios of binary responses as well as by signed response speed. Hierarchical Bayesian modeling is used to map response probabilities and response speed onto constituent psychological process, and processing capacity is also assessed using response time distribution hazard functions. The findings include characteristic order effects that change systematically in magnitude and direction with changes in the magnitude and separation of the stimuli. After Hellstr?m (1979, 2000), sensation weighting (SW) model analyses show that such order effects are reflected in the weighted accumulation of noisy information about the difference between stimulus values over time, and interindividual differences in weightings asymmetries are related to the relative processing capacity of participants. An account of SW based on the use of reference level information and maximization of signal-to-noise ratios is posited, which finds support from theoretically driven analyses of behavioral data.     

A "view from nowhen" on time perception experiments

Systematic errors in time reproduction tasks have been interpreted as a misperception of time and therefore seem to contradict basic assumptions of pacemaker-accumulator models. Here we propose an alternative explanation of this phenomenon based on methodological constraints regarding the direction of time, which cannot be manipulated in experimental settings. In two experiments, we demonstrate the influence of the direction of a dimensional change for pitch and brightness estimates. The results support the assumption that errors in time reproduction tasks do not reflect a systematic temporal misperception, but rather a methodological artifact. Implications for contemporary models of time perception are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

SUBSTANCE-ABUSING MOTHERS IN RESIDENTIAL TREATMENT WITH THEIR BABIES: IMPORTANCE OF PRE- AND POSTNATAL MATERNAL REFLECTIVE FUNCTIONING

A residential treatment program has been developed specifically for substance-abusing pregnant and parenting women in Finland, focusing on simultaneously supporting maternal abstinence from substances and the mother-baby relationship. The aims of the study are to explore maternal pre- and postnatal reflective functioning and its association with background factors, maternal exposure to trauma, and psychiatric symptoms, postnatal interaction, child development, and later child foster care placement. Participants were 34 mother-baby pairs living in three residential program units during the pre- to postnatal period. We employed self-report questionnaires on background, trauma history, and psychiatric symptoms (Brief Symptom Inventory: L.R. Derogatis, 1993; Edinburgh Postnatal Depression Scale: J.L. Cox, J.M. Holden, & R. Sagovsky, 1987; Traumatic Antecedents Questionnaire: B. Van der Kolk, 2003), videotaped mother-child interactions coded for sensitivity, control, and unresponsiveness (Care Index for Infants and Toddlers: P. Crittenden, 2003); a standardized test of child development (Bayley Scales of Infant Development-II: N. Bayley, 1993); and semistructured interviews for maternal reflective functioning (Pregnancy Interview: A. Slade, E. Bernbach, J. Grienenberger, D.W. Levy, & A. Locker, 2002; Parent Development Interview: A. Slade et al., 2005). Pre- and postnatal maternal reflective functioning (RF) was on average low, but varied considerably across participants. Average RF increased significantly during the intervention. Increase in RF level was found to be associated with type of abused substance and maternal trauma history. Mothers who showed lower postnatal RF levels relapsed to substance use more often after completing a residential treatment period, and their children were more likely to be placed in foster care. The intensive focus on maternal RF is an important direction in the development of efficacious treatment for this very high risk population.     

Effects of an Internet-based intervention for subthreshold eating disorders: a randomized controlled trial

BackgroundWomen reporting initial eating disorder (ED) symptoms are at highest risk for the development of an eating disorder. Preventive interventions should, therefore, be specifically tailored for this subgroup.AimsTo adapt and evaluate the effects of the Internet-based prevention program “Student Bodies?” for women with symptoms of disordered eating and/or subthreshold eating disorder (ED) syndromes.Method126 women, reporting subthreshold ED symptoms (high weight and shape concerns and below threshold bingeing, purging, chronic dieting or several of these symptoms) were randomly assigned to a Student Bodies?+ (SB+) intervention or a wait-list control group and assessed at pre-intervention, post-intervention, and 6-month follow-up. “Student Bodies?” was adapted to be suitable for subthreshold EDs. Main outcome measures were attitudes and symptoms of disordered eating. Pre-follow-up data were analyzed by ANCOVAS with mixed effects.ResultsAt 6-month follow-up, compared to participants in the control group, participants in the intervention group showed significantly greater improvements on ED-related attitudes. Intervention participants also showed 67% (95% CI = 20–87%) greater reductions in combined rates of subjective and objective binges, and 86% (95% CI = 63–95%) greater reduction in purging episodes. Also, the rates of participants abstinent from all symptoms of disordered eating (restrictive eating, binge eating and any compensatory behavior) were significantly higher in the intervention group (45.1% vs. 26.9%). Post-hoc subgroup analyses revealed that for participants with binge eating the effect on EDE-Q scores was larger than in the pure restricting subgroup.ConclusionThe adapted “SB+” program represents an effective intervention for women with subthreshold EDs of the binge eating subtype.     

Investigating trajectories of change in psychological distress amongst patients with depression and generalised anxiety disorder treated with internet cognitive behavioural therapy

Internet based cognitive behavioural therapy (CBT) is efficacious for the treatment of anxiety and depression. The current study aimed to examine the effectiveness of internet based CBT prescribed by primary care clinicians for the treatment of depression and generalised anxiety disorder. Psychological distress data from 302 patients who completed an online CBT course for depression and 361 patients who completed an online CBT course for generalised anxiety disorder were subjected to growth mixture analysis. For both disorders psychological distress decreased across each lesson in a quadratic trend. Two classes of individuals were identified with different trajectories of change: a large group of individuals who responded well to the courses and a smaller group of individuals with a lower response. Both groups were similar with respect to socio-demographic characteristics however the Low Responders tended to have higher levels of symptom severity and psychological distress at baseline in comparison to the responders. For the majority of patients (75-80%) the internet CBT courses for depression and generalised anxiety disorder were effective. Further research is required to identify and effectively treat the smaller proportion of patients who did not improve during internet CBT.     

Cognitive models of risky choice: parameter stability and predictive accuracy of prospect theory

In the behavioral sciences, a popular approach to describe and predict behavior is cognitive modeling with adjustable parameters (i.e., which can be fitted to data). Modeling with adjustable parameters allows, among other things, measuring differences between people. At the same time, parameter estimation also bears the risk of overfitting. Are individual differences as measured by model parameters stable enough to improve the ability to predict behavior as compared to modeling without adjustable parameters? We examined this issue in cumulative prospect theory (CPT), arguably the most widely used framework to model decisions under risk. Specifically, we examined (a) the temporal stability of CPT’s parameters; and (b) how well different implementations of CPT, varying in the number of adjustable parameters, predict individual choice relative to models with no adjustable parameters (such as CPT with fixed parameters, expected value theory, and various heuristics). We presented participants with risky choice problems and fitted CPT to each individual’s choices in two separate sessions (which were 1 week apart). All parameters were correlated across time, in particular when using a simple implementation of CPT. CPT allowing for individual variability in parameter values predicted individual choice better than CPT with fixed parameters, expected value theory, and the heuristics. CPT’s parameters thus seem to pick up stable individual differences that need to be considered when predicting risky choice.     

Dopamine, working memory, and training induced plasticity: implications for developmental research

Cognitive deficits and particularly deficits in working memory (WM) capacity are common features in neuropsychiatric disorders. Understanding the underlying mechanisms through which WM capacity can be improved is therefore of great importance. Several lines of research indicate that dopamine plays an important role not only in WM function but also for improving WM capacity. For example, pharmacological interventions acting on the dopaminergic system, such as methylphenidate, improve WM performance. In addition, behavioral interventions for improving WM performance in the form of intensive computerized training have recently been associated with changes in dopamine receptor density. These two different means of improving WM performance--pharmacological and behavioral--are thus associated with similar biological mechanisms in the brain involving dopaminergic systems. This article reviews some of the evidence for the role of dopamine in WM functioning, in particular concerning the link to WM development and cognitive plasticity. Novel data are presented showing that variation in the dopamine transporter gene (DAT1) influences improvements in WM and fluid intelligence in preschool-age children following cognitive training. Our results emphasize the importance of the role of dopamine in determining cognitive plasticity.