The prevalence of obesity, defined as a body mass index (BMI) > 30 kg/m2, is increasing to epidemic proportions. In 2014, 11% of men and 15% of women worldwide were obese. Thus, more than... Show moreThe prevalence of obesity, defined as a body mass index (BMI) > 30 kg/m2, is increasing to epidemic proportions. In 2014, 11% of men and 15% of women worldwide were obese. Thus, more than half a billion adults worldwide are classed as obese. The fundamental cause of obesity is an imbalance between energy intake (excessive intake of energy-dense foods) and energy expenditure (reduced physical activity). People with obesity are at risk for a range of chronic conditions including cardiovascular disease (CVD) and nonalcoholic fatty liver disease (NAFLD). Furthermore, obesity is a major risk factor for the development of type 2 diabetes, which is one of the most common chronic diseases in nearly all countries. According to the World Health Organization, the global prevalence of diabetes in 2014 was estimated to be 9%, of which 90% was comprised of type 2 diabetes. This thesis focuses on cardiovascular and cerebral dimensions and function in people with obesity and type 2 diabetes. State-of-the-art imaging techniques are used to investigate links between the heart, liver, abdominal fat, and brain to elucidate parts of the complex relationships between these organs. Show less
This thesis aims at providing insights in the neural mechanisms and brain structures underlying individual differences in second language acquisition. It reports on a series of experiments... Show moreThis thesis aims at providing insights in the neural mechanisms and brain structures underlying individual differences in second language acquisition. It reports on a series of experiments investigating neural correlates of novel grammar learning and of the analytical component of language aptitude, using a variety of neuroimaging methods: functional magnetic resonance imaging, diffusion tensor imaging and electroencephalography. This thesis aims at providing insights in the neural mechanisms and brain structures underlying individual differences in second language acquisition. It reports on a series of experiments investigating neural correlates of novel grammar learning and of the analytical component of language aptitude, using a variety of neuroimaging methods: functional magnetic resonance imaging, diffusion tensor imaging and electroencephalography. Show less
Peer influence plays a crucial role in the rise of health-risk behaviors during adolescence. However, there is increasing evidence that peer influence can also lead to positive psychosocial... Show morePeer influence plays a crucial role in the rise of health-risk behaviors during adolescence. However, there is increasing evidence that peer influence can also lead to positive psychosocial outcomes, such as prosocial behavior. The main goal of this thesis was to investigate peer influence on risk-taking and prosocial behavior in adolescence and to unravel its underlying neural processes. Findings showed that effects of peers on risk-taking behavior are dependent on the context. Adolescents take into account both social norms from peer feedback and the uncertainty associated with outcomes in risky decisions. Moreover, peers can both increase and decrease prosocial behavior in typically developing (TD) adolescents and those with autism spectrum disorders (ASD), illustrating that peer influence can also lead to more adaptive outcomes. Finally, we studied the neural processes underlying prosocial peer feedback and results indicate that prosocial peer influence is underlined by the social brain network, regions involved in thinking about the self and others. Eventually, the results of this thesis can contribute to interventions aimed at decreasing risk-taking and promoting prosocial behavior in adolescence, with possibly long lasting effects into adulthood. Show less
