Fig 1.
Examples of experimental stimuli and paradigm.
(A) Top plots: Examples of a quarter (1/4) note sequence (left) and an eighth (1/8) note sequence (right) with two measures. Bottom plots: amplitude profiles of the note sequences shown on the top. Each measure consists of two beats, in which one beat corresponds to one note for the quarter note sequence and two notes for the eighth note sequence. (B) Examples of musical tone sequences (MTSs, top plots) and random tone sequences (RTSs, bottom plots) with 6 notes (left) or 10 notes (right). (C) Examples of testing sequence pairs. Left: Experiment 1, tonal discrimination task. The upper row is a match trial consisting of a pair of identical note sequences. The lower row is an example of mismatch trial, in which a note in the second sequence (gray note) is shifted up one semitone, but the pitch contour (dashed line) remains the same as the first sequence. The pitch shifts of mismatch trials happen in both directions, upwards or downwards. Right: Experiment 2, N-back tonal task. An example of N = 3 testing condition. The upper row is a match trial, in which the probe note (the last note) is the same as the reference note (the 3rd to the last note). The lower row are mismatch novel note trials where the probe note is different from any prior notes in the sequence. In the mismatch adjacent note trial (right) the probe note is the same as a note prior to the reference note ((N+1)th note condition).
Fig 2.
Results of tonal discrimination task in musical tone sequence condition.
(A, C) Performance of musicians (A) and non-musicians (C) as a function of the number of measures for quarter note (black curve) and eighth note (grey curve) conditions. The performance is plotted as the d-prime value. (B, D) Performance of musicians (B) and non-musicians (D) as a function of the number of notes for quarter note (black curve) and eighth note (grey curve) conditions. (E) Combined analyses of the quarter and eighth note conditions. Performance of musicians (solid curve) and non-musicians (dashed curve) as a function of the number of notes in a sequence. Horizontal dashed lines in all plots represent the chance level. Error bars are corrected S.E.M across participants. Stars mark the significant difference comparing to the chance level.
Fig 3.
Results of tonal discrimination task in random tone sequence condition.
(A, C) Performance of musicians (A) and non-musicians (C) as a function of the number of measures for quarter note (black curve) and eighth note (grey curve) conditions. The performance is plotted as the d-prime value. (B, D) Performance of musicians (B) and non-musicians (D) as a function of the number of notes for quarter note (black curve) and eighth note (grey curve) conditions. (E) Combined analyses of the quarter and eighth note conditions. Performance of musicians (solid curve) and non-musicians (dashed curve) as a function of the number of notes in a sequence. Horizontal dashed lines in all plots represent the chance level. Error bars are corrected S.E.M across participants. Stars mark the significant difference comparing to the chance level.
Fig 4.
(A, B) Performance of musicians (A) and non-musicians (B) as a function of the notes between the reference and probe notes (N) for quarter note (black curve) and eighth note (grey curve) conditions. (C) Combined analyses of the quarter and eighth note conditions. Horizontal dashed lines in all plots represent the chance level. Error bars are corrected S.E.M across participants. Stars mark the significant difference comparing to the chance level.
Table 1.
t-test analysis for Experiment 2.
Fig 5.
Comparison between the novel and adjacent notes in the N-back tonal task.
Performance of musicians (A) and non-musicians (B) as a function of the notes between the reference and probe notes (N) when the probe note was a novel note (black curve) or identical to a note adjacent to the reference note (grey curve). The performance is plotted as the accuracy (RAU). Horizontal dash lines in all plots represent the chance level. Error bars are corrected S.E.M across participants.
Fig 6.
Performance across testing stages.
Performance of musicians (gray box) and non-musicians (open box) is plotted for each of the four testing stages. The performance is plotted as the RAU value. Each box represents percentiles of the data. The line within the box indicates the median. Error bars represent the minimums and maximum values. Small circles indicate the outliers. The significant difference between musician and non-musicians groups is indicated by the asteroids above the two boxes for each testing stage. (A) MTS condition in Experiment 1. Musicians’ performance is significantly higher than non-musicians at all four testing stages. (B) RTS condition in Experiment 1. No significant difference between musicians and non-musicians. (C) Experiment 2. Musicians’ performance is significantly higher than non-musicians at stages 1, 2, and 3, but not at stage 4. The significant difference was marked as stars.