Effects of emotion induced by music on experimental pain Roy, Mathieu (1), Peretz, Isabelle (1), Rainville, Pierre (2)

1. Effects of emotion induced by music on experimental pain Roy, Mathieu (1), Peretz, Isabelle (1), Rainville, Pierre (2) (1) Département de psychologie, (2) Départment de stomatologie, Université de Montréal RESULTS 1. The sad and happy music and the silence condition have different effects on pain ratings. INTRODUCTION Pain is a complex experience not only made up of the initial pain sensation, but also of the emotional reactions associated. Emotional states can also influence our pain perception in an important way (Keefe, 2001). By its capacity to influence our emotional states, music seems to be specifically suited to modify our pain experience. Many studies have observed an analgesic effect of music (Maslar, 1986). However, most of these study cannot determine wich mecanisms are responsible for this effect. On one hand, music could reduce pain perception by disraction. On the other hand, the various emotions induced by music could differently modify pain perception. In order to assess the influence of the emotions conveyed by music on pain perception, we compared the effects of sad and happy music on experimental pain intensity and unpleasantness.   3. Pain INT but not UNP decreases with reductions in arousal whereas pain UNP but not INT decreases with augmentations in pleasantness. METHODS Participants:- 10 musicians (5 males, 5 females) Experimental conditions: - 15 min. of happy music selected on an individual basis; - 15 min. of sad music selected on an indivudual basis; - 15 min. of silence; Pain stimulation: - 32 stimulations (40°C, 45°C, 47°C et 49°C; length; counterbalanced orders). - duration: 4 sec.; - Inter-stimulus interval > 10 sec.; - Location: 4 spots on te volar surface of each forearm; Evaluation of stimuli: - Thermal: - non-painful: warmth scale (0 to 100; 100 = pain treshold); - painful: 1. pain intensity scale (0 to 100+) 2. pain unpleasantness scale (0 to 100+) - Music: - happiness (0 to 10) - sadness (0 to 10) - arousal (A to I, converted to 0-relaxing to 9-stimulating) - valence (A to I, converted to 0-pleasant to 9-unpleasant) Procedure: Throughout 3 experimental sessions, sequences of 32 thermal stimulations were administered to the participants during the last ten minutes of each experimental conditions (happy, sad, silence; orders counterbalanced). Participants had to evaluate separately pain intensity (INT) and unpleasantness (UNP) for stimulations that were perceived as painful and the warmth of the stimulations for the remaining. After each condition, subject rated the music or silence on four dimensions: happiness, sadness, arousal and emotional valence. Fig. 3. Correlation between the change (music–silence) in pain intensity and the differences (musique-silence) in arousal and valence ratings. Fig 1. An ANOVA (3 factors: experimental condition (Sad, Happy, Silence), temperature (40, 45, 47, 49), pain ratings (INT or UNP)) revealed a main effect of temperature (F(3, 27) = 66,175; p<0.01), pain ratings being higher for higher temperature. A main effect of the experimental condition was also observed (F(2, 18) = 5,618; p<0.05), pain ratings being higher during the presentation of sad music than happy music (F(1,9)=10,363, p<0.05). CONCLUSION The difference observed between the effects on pain ratings of sad and happy musics cannot be explained by a non-specific distracting effect of music on pain. Thus, these results suggest a role of the emotion conveyed by music in the modulating effects of music on pain. The correlation between the valence of the emotions induced by music and pain unpleasantness suggests that this dimension of music is determinant in the effects observed. However, the ambiguity of the emotional valence of sad music (pleasant but sad) might mask this effect. Music with a pleasant valence and low arousal may better relieve pain. 2. Changes in pain ratings, but not warmth ratings, are higher during the presentation of sad music than during the presentation of happy music. REFERENCES Keefe, F.J., et al. (2001), Pain and emotion: New research directions, Journal of Clinical Psychology, 57(4), pp. 587-607. Maslar, P..M. (1986), The effects of music on the reduction of pain: A review of the litterature, The Arts in Psychotherapy, 13, pp. 215-219. Fig 2. Difference in pain ratings between each music condition and the silence condition were calculated for each temperature. An ANOVA (3 factors: music (happy-silence, sad-silence), temperature (40, 45, 47, 49) and pain ratings (INT or UNP)) revealed a main effect of music (F(1,9) = 7,812; p<0.05). Differences in pain INT are similar to the differences in pain UNP represented above (F(1,9) = 11,596; p<0.01). However, changes in warmth ratings were not different for sad and happy music (t (9)=0.108; p=0,916). Mean warmth ratings for the silence condition (X axis) was 21,986.