The rewarding aspects of music listening are related to degree of emotional arousal

Abstract

Background: Listening to music is amongst the most rewarding experiences for humans. Music has no functional resemblance to other rewarding stimuli, and has no demonstrated biological value, yet individuals continue listening to music for pleasure. It has been suggested that the pleasurable aspects of music listening are related to a change in emotional arousal, although this link has not been directly investigated. In this study, using methods of high temporal sensitivity we investigated whether there is a systematic relationship between dynamic increases in pleasure states and physiological indicators of emotional arousal, including changes in heart rate, respiration, electrodermal activity, body temperature, and blood volume pulse.

Methodology: Twenty-six participants listened to self-selected intensely pleasurable music and "neutral" music that was individually selected for them based on low pleasure ratings they provided on other participants' music. The "chills" phenomenon was used to index intensely pleasurable responses to music. During music listening, continuous real-time recordings of subjective pleasure states and simultaneous recordings of sympathetic nervous system activity, an objective measure of emotional arousal, were obtained.

Principal findings: Results revealed a strong positive correlation between ratings of pleasure and emotional arousal. Importantly, a dissociation was revealed as individuals who did not experience pleasure also showed no significant increases in emotional arousal.

Conclusions/significance: These results have broader implications by demonstrating that strongly felt emotions could be rewarding in themselves in the absence of a physically tangible reward or a specific functional goal.

Figure 1. Assessment of Pleasure and Emotional Arousal.

Emotional arousal was assessed through psychophysiological measurements of galvanic skin response (GSR), temperature, heart rate, blood volume pulse (BVP) amplitude, and respiration rate. Pleasure states were continuously obtained through subjective ratings of “neutral”, “low pleasure”, and “high pleasure” using a button box. Chills were also indicated through button presses. Psychophysiological correlates of each pleasure state were analyzed to determine systematic relationships between increases in pleasure and emotional arousal.

Figure 2. Relationship between Pleasure and Emotional Arousal.

Data showed significant positive correlations between subjectively reported pleasure states and objectively measured increases in autonomic nervous system activity for all physiological measures. Participants who reported “no pleasure” on the same epochs of the same musical excerpts revealed no significant changes in physiological activity.

Figure 3. Relationship between Pleasure and the Chills Response.

Real-time pleasure ratings plotted against the time-course of the chills response reveal that chills are experienced at the peak of pleasure ratings. Individuals who experienced no pleasure to the same excerpts showed no increases in pleasure during the epochs that chills were experienced in individuals who found the music highly pleasurable.

Figure 4. Time-Course of the Chills Response.

Real-time physiological recordings plotted against the time-course of the chills response reveal that chills are experienced during the peak of sympathetic nervous system activity. Individuals who experienced no pleasure to the same excerpts did not show significant changes in psychophysiological responses during the epochs that chills were experienced in individuals who found the music highly pleasurable.

Figure 5. Perceived versus Felt Emotions.

Post-listening ratings of valence and arousal revealed significant differences amongst the self-selected and experimenter-selected musical pieces. Self-selected excerpts revealed higher correlations between perceived and felt valence and arousal than experimenter-selected pieces. Furthermore, participants generally reported lower arousal and a more “neutral” valence on experimenter-selected pieces than self-selected pieces.