Kevin Andersson and Eric Lindgren defended their Master thesis on 2 June 2021. Congrats!

Kevin Andersson and Eric Lindgren defended their Master thesis on 2 June 2021. Congrats!

Title: Saliency mapping of RS-fMRI data in GCNs for sex and brain age prediction
Subtitle: Identifying important functional brain networks using explainability in Graph Convolutional Networks

Insights into how biological sex and healthy ageing affects the human brain are important for an increased understanding of the brain. Healthy ageing insights are also useful for clinical applications, for instance in identifying unhealthy ageing due to neurodegenerative disease. To this end, several studies in the last few years have used machine learning methods on neuroscientific data to predict subject sex and brain age. One particularly interesting approach has been to represent functionally connected networks in the brain as graphs, and apply Graph Convolutional Networks (GCNs). To investigate which functional brain networks are connected with sex and age, we develop and analyse GCN-based models that predicts sex and age from resting-state fMRI data. The analysis of the models is done using saliency mapping techniques which gives insight into what functional brain networks in the data are relevant for the predictions. With this approach, we obtain a sex prediction accuracy of up to 79% and an age prediction MAE of 5.9 years. Furthermore, we find indications that the Sensory Motor Network and the cerebellum are among the more important functional brain networks for predicting sex and brain age.

​Master programme: Physics
Supervisor: Alice Neimante Diemante (Syntronic AB)
Examiner: Giovanni Volpe, Department of Physics, University of Gothenburg
Opponent: Rasmus Svensson

Place: Online via Zoom
Time: 2 June, 2021, 16:00

Kevin Andersson, Sofia Cvetkovic Destouni, Ebba Ekblom, Lilian Hee, Emil Jansson & Thomas Otting defended their Bachelor Thesis. Congrats!

Kevin AnderssonSofia Cvetkovic Destouni, Ebba EkblomLilian HeeEmil JanssonThomas Ottink defended their Bachelor Thesis at Chalmers University of Technology on 29 May 2019.

Title: Agenters sökförmåga i komplexa miljöer

Abstract: Tendensen hos en aktiv Brownsk agent att svänga i en viss rikting benämns i denna studie som kiralitet och ger upphov till vad som kallas cirkulär Brownsk rörelse. Denna typ av rörelse förekommer i många både naturliga och tekniska sammanhang och har potentiella applikationer inom bland annat medicin, biologi och robotik. För att undersöka hur cirkulärt Brownska agenters sökförmåga påverkas av kiralitet utförs i detta kandidatarbete en kombination av simuleringar och experiment i olika miljöer. Simuleringarna baseras på en diskretisering av Langevins ekvationer i två rumsdimensioner och experimenten utförs med hjälp av vibrerande mikrorobotar. Studien visar att agenters sökförmåga minskar vid ökande kiralitet i homogen miljö och bestämmer kiralitetsoptimum för sökförmåga i cirkulärt begränsade miljöer. I ett fall där två agenter placeras i en cirkulärt begränsad miljö identifieras effektiva kiralitetskombinationer för korta mötestider samt en möjlig koppling mellan sökförmåga och mötestid.

Supervisors: Alessandro Magazzù & Giovanni Volpe, Department of Physics, University of Gothenburg
Examiner: Lena Falk, Department of Physics, University of Gothenburg
Opponent: Matilda Hanes & Kevin Rylander
Place: FL72
Time: 29 May, 2018, 9:35-10:20