Employing an extended 10–20 system (e.g., Jurcak et al., 2007; Pivik et al., 1993) 67-channel montage, continuous EEG was acquired with a 24-bit Biosemi ActiveTwo system (256 samples/s; DC-128 Hz) using a Lycra stretch electrode cap and external electrodes for nose tip (used as off-line reference) and for monitoring bipolar eye activity (left and right outer canthi; above and below right eye). Volume-conducted blink artifacts were effectively removed from the continuous EEG by means of spatial PCA (NeuroScan, 2003; for further details, see Kayser et al., 2010).
