Resting EEG was recorded while subjects sat quietly in a sound attenuated booth during four 2-minute resting EEG periods (eyes-closed [C] and eyes-open [O] counterbalanced across blocks: COOC or OCCO; order alternated across subjects in each group). Subjects were instructed to remain still and inhibit blinks or eye movements during each recording period. During the eyes-open condition, subjects fixated on a central cross. Continuous EEG was acquired at 256 samples/s using the 24-bit Biosemi system and nose-referenced data were exported into 16-bit Neuroscan format using Polyrex (43) to remove offsets, optimize scaling, and rereference the EEG.
