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.     

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.     

A simple and inexpensive telemetry system for measuring deep body temperature in rodents

An easily constructed telemetry system for measuring deep body temperatures in rodents is described and data collected with the system is presented. The system allows continual monitoring of core temperature without interfering with concomitant behavioral or physiological measurements.     

A Hierarchical Ornstein–Uhlenbeck Model for Continuous Repeated Measurement Data

In this paper, we present a diffusion model for the analysis of continuous-time change in multivariate longitudinal data. The central idea is to model the data from a single person with an Ornstein–Uhlenbeck diffusion process. We extend it hierarchically by allowing the parameters of the diffusion process to vary randomly over different persons. With this approach, both intra and interindividual differences are analyzed simultaneously. Furthermore, the individual difference parameters can be regressed on covariates, thereby providing an explanation of between-person differences. Unstructured and unbalanced data pose no problem for the model to be applied. We demonstrate the method on data from an experience sampling study to investigate changes in the core affect. It can be concluded that different factors from the five factor model of personality are related to features of the trajectories in the core affect space, such as the cross-correlation and variability of the changes.     

Cross-modality matches between color and size differences

Eighteen undergraduates, 9 males and 9 females, were asked to make two geometric figures appear as different as two primary colors. They adjusted the size of one of the figures. There was a significant relation between the ratio of wave lengths of the colors and the ratios produced between the figures. Females tended to see a given color pair as more different than males.     

Assessment of Developed General Intellectual Ability with Nonverbal Measures

A canonical correlation analysis was performed between two measures of general intellectual ability: The D. 48 Test and the Standard Progressive Matrices were taken as one set of variables, and general scholastic ability, verbal and quantitative ability, English and mathematics achievement, time spent in school, and ethnic/cultural group membership were used as the second set of variables. Subjects were 180 girls attending a large urban parochial high school. The D. 48 Test performances made a substantial contribution to the first canonical variate associated with the only significant canonical correlation; quantitative ability performances made a substantial contribution to the second variate. Matrices performances and performances in mathematics achievement and general scholastic ability made lesser contributions to their respective variates.     

The linear mixed model and the hierarchical Ornstein–Uhlenbeck model: Some equivalences and differences

We focus on comparing different modelling approaches for intensive longitudinal designs. Two methods are scrutinized, namely the widely used linear mixed model (LMM) and the relatively unexplored Ornstein–Uhlenbeck (OU) process based state‐space model. On the one hand, we show that given certain conditions they result in equivalent outcomes. On the other hand, we consider it important to emphasize that their perspectives are different and that one framework might better address certain types of research questions than the other. We show that, compared to a LMM, an OU process based approach can cope with modelling inter‐individual differences in aspects that are more substantively interesting. However, the estimation of the LMM is faster and the model is more straightforward to implement. The models are illustrated through an experience sampling study.     

A hierarchical latent stochastic differential equation model for affective dynamics

In this article a continuous-time stochastic model (the Ornstein-Uhlenbeck process) is presented to model the perpetually altering states of the core affect, which is a 2-dimensional concept underlying all our affective experiences. The process model that we propose can account for the temporal changes in core affect on the latent level. The key parameters of the model are the average position (also called home base), the variances and covariances of the process, and the regulatory mechanisms that keep the process in the vicinity of the average position. To account for individual differences, the model is extended hierarchically. A particularly novel contribution is that in principle all parameters of the stochastic process (not only the mean but also its variance and the regulatory parameters) are allowed to differ between individuals. In this way, the aim is to understand the affective dynamics of single individuals and at the same time investigate how these individuals differ from one another. The final model is a continuous-time state-space model for repeated measurement data taken at possibly irregular time points. Both time-invariant and time-varying covariates can be included to investigate sources of individual differences. As an illustration, the model is applied to a diary study measuring core affect repeatedly for several individuals (thereby generating intensive longitudinal data).