Ps (Mehring el al.. 2003. 2004; Leuthardt et al.. 2004; Rickert et at. 2005: Scherberger et al., 2.005; Schalk et al., 2007: Pistohl et al., 2008; Sanchez et al., 2008). In the late 1990s, pioneering work on the macroscale began to relate scalp potentials acquired non-invasively to hand movement (Kelso et a