Stenroos and Nummenmaa, 2016). To date, anatomically realistic and sufficiently detailed head models can be constructed from the segmentation of structural head images (usually MRI or computed tomography scans; for guidelines, see Vorwerk et al., 2014). Nonetheless, the forward model accuracy is still limited by approximations in geometry structures, uncertainty in conductivity values (Akhtari et al., 2002; Dannhauer et al., 2011), as well as errors in head-to-sensor co-registration (Adjamian et al., 2004; Troebinger et al., 2014; Chella et al., 2019).