2.5. EEG Recording
EEG data were continuously recorded through all phases via 32 Ag-AgCl scalp electrodes placed according to the International 10–20 system (ANT, Neuro, The Netherlands). The signals were recorded and online filtered at 0.3–30 Hz with reference to CPz at a sampling rate of 1000 Hz. All electrode impedances were below 10 kΩ.