The EEG was recorded from 67 expanded 10–20 system locations (40) with a Lycra stretch electrode cap (ActiveTwo EEG system; 41) using an active reference at sites PO1 (common mode sense) and PO2 (driven right leg). Along with 11 midline sites, the montage consisted of 28 homologous pairs over the left and right hemisphere, extending laterally to include the inferior temporal lobes (cf. 42). Electrode placement was optimized by direct measurement of landmarks (nasion, inion, auditory meatus, vertex). The scalp placements were prepared using a conventional water-soluble electrolyte gel, and the interface verified (ActiView; 41). Additional electrodes above and below the right eye, and at the left and right outer canthi provided bipolar electrooculogram recordings for identification and rejection of blinks and eye movements.
