Wearable EEG Monitoring Protocol

EEG activity was acquired with a SOMNOwatch + EEG-6 (Somnomedics GmbH, Randersacker, Germany) at a sampling rate of 256 Hz with a band pass filter of 0.1–80 Hz. For a detailed description of this wearable EEG device, see Ref. [2 (link)]. We used a monopolar montage with gold cup electrodes (Natus Neurology Incorporated—Grass Products Warwick, US) at six active scalp sites—F3, F4, T3, T4, O1, and O2—placed according to the international 10/20 system [63 ] and using CZ as a reference. The ground was placed at FpZ. Impedance was kept lower than 5 kΩ. We chose these specific sites keeping in mind helmet-based physiological monitoring system applications [64 (link),65 (link)]. Electrooculography (EOG) activity was also recorded using a golden cup electrode placed in the outer canthus of the right eye (horizontal EOG channel) and another one below the left eye (vertical EOG channel) using a bipolar configuration. The device collected the raw EEG data internally. DOMINO Light software (version 14.0, Somnomedics GmbH, Randersacker, Germany) was used to export raw data to EDF+ files. From 4 out of 39 participants, due to log system failures during the EEG recordings, we only analyzed performance and subjective data.