EEG Recording and Procedure

The EEG experiment (64-electrode ActiveTwo system, BioSemi B.V., Amsterdam, Netherlands) consisted of four series, each lasting for 11 min, and additional pre- and post-experiment resting state EEG recordings. Two reference electrodes were attached to the earlobes, and four single electrodes to record eye-movements and blinks were attached to the participants face, close to the eyes. The earlobe reference electrodes were linked in post-processing. The EEG data were recorded using a 512 Hz frequency and 0.6–100 Hz filters. The auditory stimuli were presented to the headphones with custom MATLAB (MathWorks, Natick, MA, United States) programs, always with the same volume not exceeding 60 dB HL (hearing level). To distract their attention away from the presented sounds, the participants watched a soundless cartoon on the Mitsubishi Diamond Pro 2070SB 22′′ computer screen (Mitsubishi Electric, Tokyo, Japan) (participant’s chair was approximately 114 cm away from the screen).