Contextual conditioning in rats as an animal model for generalized anxiety disorder

Animal models of psychiatric disorders are important translational tools for exploring new treatment options and gaining more insight into the disease. Thus far, there is no systematically validated animal model for generalized anxiety disorder (GAD), a severely impairing and difficult-to-treat disease. In this review, we propose contextual conditioning (CC) as an animal model for GAD. We argue that this model has sufficient face validity (there are several symptom similarities), predictive validity (it responds to clinically effective treatments), and construct validity (the underlying mechanisms are comparable). Although the refinement and validation of an animal model is a never-ending process, we want to give a concise overview of the currently available evidence. We suggest that the CC model might be a valuable preclinical tool to enhance the development of new treatment strategies and our understanding of GAD.     

Does the name-race implicit association test measure racial prejudice?

Research using the Implicit Association Test (IAT) has shown that names labeled as Caucasian elicit more positive associations than names labeled as non-Caucasian. One interpretation of this result is that the IAT measures latent racial prejudice. An alternative explanation is that the result is due to differences in in-group/out-group membership. In this study, we conducted three different IATs: one with same-race Dutch names versus racially charged Moroccan names; one with same-race Dutch names versus racially neutral Finnish names; and one with Moroccan names versus Finnish names. Results showed equivalent effects for the Dutch-Moroccan and Dutch-Finnish IATs, but no effect for the Finnish-Moroccan IAT. This suggests that the name-race IAT-effect is not due to racial prejudice. A diffusion model decomposition indicated that the IAT-effects were caused by changes in speed of information accumulation, response conservativeness, and non-decision time.     

The perception of limb orientation depends on the center of mass

Three experiments were conducted to test the hypothesis that the perception of limb orientation depends on inertial eigenvectors against the alternative that it depends on the center of mass. In all experiments, each participant pointed at visible targets with his or her occluded right arm while center-of-mass and inertial eigenvectors were manipulated independently. In Experiments 1 and 2, the arm was constrained to rotate exclusively about the shoulder, whereas in Experiment 3, the arm was allowed to rotate freely about both the shoulder and the elbow. The mechanical manipulations were applied either in the horizontal (Experiments 1 and 3) or vertical (Experiment 2) plane. Across experiments, pointing direction was affected by the center of mass and not by the inertial eigenvectors, albeit that simultaneous manipulation of both resulted in a more pronounced pointing bias than the isolated center-of-mass manipulation. These findings challenge the inertial eigenvector hypothesis and suggest that the center of mass plays a generic role in the perception of limb orientation.     

Defensive and offensive behaviours in a Kleefstra syndrome mouse model

Animal Cognition - Kleefstra syndrome in humans is characterized by a general delay in development, intellectual disability and autistic features. The mouse model of this disease (Ehmt1±)...     

Visual Geometry of Classical Japanese Gardens

Axiomathes - The concept of geometry may evoke a world of pure platonic shapes, such as spheres and cubes, but a deeper understanding of visual experience demands insight into the perceptual...