[1] Univ Turku, Div Clin Neurosci, POB 52, FIN-20521 Turku, Finland
[2] Turku Univ Hosp, POB 52, FIN-20521 Turku, Finland
[3] Massachusetts Gen Hosp, Athinoula A Martinos Ctr Biomed Imaging, Boston, MA 02114 USA
[4] Harvard Med Sch, Boston, MA USA
[5] Beth Israel Deaconess Med Ctr, Berenson Allen Ctr Noninvas Brain Stimulat, Boston, MA 02215 USA
[6] Univ Turku, Turku PET Ctr, Turku, Finland
[7] Univ Turku, Dept Biostat, Turku, Finland