Investigating emotional changes induced by chords: A psychophysiological approach

Although it is well known that the elements that make up music influence human physiological information and the direction of emotions after listening to music, the underlying mechanisms remain unclear. Clarifying this mechanism requires identifying musical elements involved in emotional transitions. It also requires accurately capturing the emotional processing that occurs during music listening. Previous studies have only clarified the relationship between musical elements and either psychological or physiological indicators, and the relationship between the three has not been clarified. These studies focused on temporal characteristics such as tempo and melody. However, the influence of chords, a frequency domain component conveying emotional impressions, has not been sufficiently studied. This study aims to clarify the physical properties of chords related to emotional transitions as measured by psychological and physiological indicators during music listening with manipulated chords. Participants listened to stimuli with systematically manipulated chords while their emotional responses were assessed via self-report tests (e.g., STAI, PANAS, TDMS) and physiological measurements (e.g., pulsebeat variability, skin conductance). The results indicated a relationship between the physical properties of chords and both psychological and physiological responses, which was quantitatively demonstrated through structural equation modeling.