Music stimuli
To achieve a higher level of ecological validity, the music stimuli utilized in this study were self-provided by the participants. Before the participants came to the experiment, we asked them to provide music audio files or playlists with a total duration of 40 or more minutes. These music tracks should be what the participants often liked to listen to during self-learning or reading in their daily lives. For participants who did not use to listen to music while studying, they were instructed to provide music they would not mind listening to while reading. Researchers pre-processed and standardized the music by adding fading in and fading out effects and shortening silent segments if any. The headphone was adjusted to a range from 65 to 75 dB(A), which was acceptable for learning as suggested in the literature