“…Functional magnetic resonance imaging (fMRI) is widely used to investigate brain function during different motor tasks and various sensory stimulations in humans (Fransson et al, 1998(Fransson et al, , 1999Hofbauer et al, 2004Hofbauer et al, , 2006Hwang et al, 2005;Olausson et al, 2005;Seung et al, 2005;Elfgren et al, 2006;Pastor et al, 2006). The most commonly used technique relies on blood oxygenation level-dependent (BOLD) contrast, which is indirectly related to neuronal activity (Ogawa et al, 1993;Heeger and Ress, 2002;Thompson et al, 2003;Mukamel et al, 2005;Niessing et al, 2005).…”