Effects of Canon chord progression on brain activity and motivation are dependent on subjective feelings, not the chord progression per se

A number of studies have indicated that relaxing and pleasant melodies are useful for the treatment of patients with psychiatric disorders, including schizophrenia, depression, and dementia. However, few studies have investigated what constitutive elements of the music had an effect on brain activity. As Canon chord progression is one of critical elements for pleasant melodies, we sought to examine the effects of Canon chord progression and pitch-shifted Canon chord progression on brain activity using performance on the auditory oddball task during event-related potentials (ERPs) in 30 healthy subjects. Unexpectedly, we found no differences in ERP components between subjects listening to Canon chord progression (n=15) or pitch-shifted Canon chord progression (n=15). Next, we divided participants into two groups: those who found the melody pleasant (n=17) and those who did not (n=13), for both Canon chord progression and pitch-shifted Canon chord progression. The average of P300 amplitude was higher at Fz in subjects found the music pleasant versus those finding it unpleasant. Moreover, subjects who found it pleasant exhibited higher motivation scores than those who felt it was unpleasant, whereas listening to Canon chord progression did not matter. These findings suggest that the effects of Canon chord progression on brain activity and motivation depend on subjective feelings, not the chord progression per se.