2.5. EEG Recording
BRAIN
A full report of the EEG recording and processing is available in the Sixty Ag/AgCl active electrodes were mounted into an elastic cap (actiCAP, Brain Products GmbH, Gilching, Germany) and placed in accord with the 10-10 system at scalp sites FP1, FP2, AF7, AF3, AFz, AF4, AF8, F7, F5, F3, F1, Fz, F2, F4, F6, F8, FT7, FC5, FC3, FC1, FCz, FC2, FC4, FC6, FT8, C5, C3, C1, Cz, C2, C4, C6, TP9, TP7, CP5, CP3, CP1, CPz, CP2, CP4, CP6, TP8, TP10, P7, P5, P3, P1, Pz, P2, P4, P6, P8, PO7, PO3, POz, PO4, PO8, O1, Oz, and O2. Four additional electrodes were used to record horizontal (HEOG) and vertical electrooculograms (VEOG). The VEOG was recorded by placing electrodes above and below the right eye. HEOG was recorded by placing electrodes at the right and left outer canthi. The ground electrode was placed at scalp location Fpz, and electrode Cz was used as the recording reference. The EEG and EOG signal was DC recorded continuously (filter: {type: IIR Butterworth 2nd order causal lowpass; high cutoff frequency: 280 Hz (−3 dB); sampling rate: 1000 Hz; resolution: 0.0488281 µV}). An actiCHamp amplifier (Brain Products, Gilching, Germany) and BrainVision Recorder software (v1.22.0001, Brain Products, Gilching, Germany) were used for recording. Impedances were kept <10 kΩ.