Simone Walser

Motor Processes in Children's Mental Rotation

Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a mental rotation task while simultaneously rotating their hand (guided by a handle). The direction of the manual rotation was either compatible or incompatible with the direction of the mental rotation. Response times increased with increasing stimulus orientation angles, indicating that participants of all age groups used mental rotation to perform the task. A differential effect of the compatibility of manual rotation and mental rotation was found for 5-year-olds and 8-year-olds, but not for 11-year-olds and adults. The results of this study suggest that the ability to dissociate motor from visual cognitive processes increases with age.

Homicide clearance in Western Europe

This study provides an overview of homicide clearance in four West European countries: Finland, the Netherlands, Sweden and Switzerland. Using data from the European Homicide Monitor, employing similar definitions and uniform coding schemes, this study allowed for unique cross-country comparisons in factors influencing differences in homicide clearance rates. Findings based on homicides occurring in the period 2009–14 revealed overall low homicide rates in all countries, with a wide variety in homicide clearance rates, ranging from 77 percent in the Netherlands to 98 percent in Finland. Results further showed that both event-based as well as victim-based characteristics significantly influenced the likelihood of homicide clearance, suggesting that homicide clearance rates can, for a large part, be attributed to the prevalent types of homicide in each of these European countries.