Figure 1.
Pseudospectrogram schematic of stimuli in three stimulus types with the starting point of k = 220 Hz. Time is plotted on the abscissa, whereas frequency is plotted on the ordinate. Each horizontal line represents one tone, a sine wave of a fixed frequency lasting 600 ms each. Chord progressions, each with four sequential chords and each chord consisting of three simultaneous tones, were played to participants during EEG recording. Stimuli consisted of 70% standard chord progressions, 20% deviant chord progressions (where the third chord was different from the standard), and 10% fadeout chord progressions (where 1 of the 4 chords faded out in volume). Participants' task was to detect the fadeout chords.