Early neural responses underlie advantages for consonance over dissonance

Abstract

Consonant musical intervals tend to be more readily processed than dissonant intervals. In the present study, we explore the neural basis for this difference by registering how the brain responds after changes in consonance and dissonance, and how formal musical training modulates these responses. Event-related brain potentials (ERPs) were registered while participants were presented with sequences of consonant intervals interrupted by a dissonant interval, or sequences of dissonant intervals interrupted by a consonant interval. Participants were musicians and non-musicians. Our results show that brain responses triggered by changes in a consonant context differ from those triggered in a dissonant context. Changes in a sequence of consonant intervals are rapidly processed independently of musical expertise, as revealed by a change-related mismatch negativity (MMN, a component of the ERPs triggered by an odd stimulus in a sequence of stimuli) elicited in both musicians and non-musicians. In contrast, changes in a sequence of dissonant intervals elicited a late MMN only in participants with prolonged musical training. These different neural responses might form the basis for the processing advantages observed for consonance over dissonance and provide information about how formal musical training modulates them.

Keywords: Consonance; Dissonance; MMN; Music processing; Musical training.

Fig. 1

Graphical depiction of interval sequences used in the present study (see Table 1 for abbreviations). In both the Consonance condition and the Dissonance condition, sequences of standard, frequent, stimuli are interrupted by deviant, infrequent, stimuli.

Fig. 2

ERPs and scalp topographies elicited for changes in consonant and dissonant sequences for non-musicians. Difference waves (black line) are the result of substracting the averaged response to standard stimuli (continuous line) from the averaged response to deviant stimuli (dashed line) in the Fz electrode. In the consonance condition two significant components were observed, an early positivity (P1) and a later negativity (MMN). For the dissonance condition no significant components were found. Scalp topographies reflect the activity for all the participants during the timing consistent with a MMN component.

Fig. 3

ERPs and scalp topographies elicited for changes in consonant and dissonant sequences for musicians. Difference waves (black line) are the result of substracting the averaged response to standard stimuli (continuous line) from the averaged response to deviant stimuli (dashed line) in the Fz electrode. In the Consonance condition two significant components were elicited, a MMN and a later negativity (N5). In the dissonance condition a MMN component was also elicited. Scalp topographies reflect the activity for all the participants during the timing consistent with a MMN component.

Fig. 4

ERPs for consonant intervals (left panel) and dissonant intervals (right panel) in the Fz electrode depending on whether they are presented as standard or as deviant stimuli.

Fig. 5

ERPs for standard (left panel) and deviant (right panel) stimuli in the Fz electrode depending on whether they are implemented over consonant or dissonant intervals.

Fig. 6

Difference waves after changes in consonant and dissonant sequences for musicians and non-musicians.