Ronja Thieleking

I am mainly interested in the interplay of memory and food choices on a behavioural and neural level. Besides the behavioural analysis, I studied the role of the uncinate fasciculus in this interplay. The uncinate is a large white matter bundle that connects the brain’s reward areas (OFC/PFC) with the areas involved in emotion and memory processes, namely the amygdala and hippocampus. To investigate the interplay, we ran a dietary intervention study with functional, structural and diffusion-weighted MR imaging. Food choices based on reward expectation seems to influence food memory but is independent of the underlying white matter coherence. This finding furthers the field of food decision-making emphasizing the possibility that choosing unhealthy food might promote better memory of this food item and thereby lead to repetitious selection – a vicious cycle that could contribute to the development of obesity.

Following more physics-related interests, I investigated the impact of scanner, sequence and preprocessing pipeline on diffusion imaging outcome parameters. To do so, I evaluated quantitative differences in the images of matched diffusion-weighted sequences collected on two Siemens 3T Magnetom MRI scanners, Verio and Skyra. This way, we demonstrated that DTI outcome measures strongly depend on imaging site and software, and that these biases vary between brain regions. These regionally inhomogeneous biases may exceed and considerably confound physiological effects such as ageing, highlighting the need to harmonise data acquisition and analysis.

Working with diffusion-weighted images, I also compared different artefact removal tools on a quantitative level. The aim was to integrate a tool to reduce Gibbs Ringing artefact in the standard preprocessing pipeline of diffusion-weighted images.