Data acquisition and analysis
The EEG was recorded continuously during the two sessions through
the Active Two Biosemi system from 64 active electrodes mounted on an
elastic cap (10–20 International system Electro-Cap Inc). The impedance
of all electrodes was kept below 5 kΩ. Two additional electrodes were
used to monitor eye movements and blinks (one placed at lateral canthi
and one below the eyes).