1. Department of Neuroscience and Biomedical Engineering, Aalto University, FI-00076 Espoo, Finland
2. Turku PET Centre, University of Turku, FI-20520 Turku, Finland
3. Department of Computer Science, Aalto University, FI-00076 Espoo, Finland
4. Helsinki Institute for Information Technology, Aalto University, FI-00076 Espoo, Finland
5. Aalto NeuroImaging, Aalto University, FI-00076 Espoo, Finland
6. Department of Neuroscience, University Medical Center of Geneva, CH-1211 Geneva, Switzerland
7. Swiss Center for Affective Sciences, Campus Biotech, University of Geneva, CH-1211 Geneva, Switzerland
8. Department of Psychology, University of Turku, FI-20520 Turku, Finland