This study examines the effects of music and positive emotional states on autonomic and immune function in normal, healthy individuals. Autonomic activity was assessed using power spectral density analysis of heart rate variability, and salivary iga was used as a marker of immunity. The effects of Rock, New Age, and Designer Music were examined alone, and in conjunction with a self-induced positive emotional state. The results indicate that only the Designer Music and the self-induced state of appreciation produced a significant increase in autonomic activity and salivary iga (S-iga). In addition, the combination of the Designer Music and the self-induced appreciation produced a much greater immunoenhancement than either of these two conditions alone. We conclude that music can be designed to enhance the beneficial effects of positive emotional states on immunity, and that this effect may be mediated by the autonomic nervous system. These data raise the tantalizing possibility that music and emotional self-management may have significant health benefits in a variety of clinical situations in which there is immunosuppression and autonomic imbalance.
It is well recognized that mental and emotional activity can alter autonomic nervous system (ANS) function [1, 2]. Similarly the ANS has been shown to profoundly affect the cardiovascular [3], neuroendocrine [4] and immune functions [5]. It has been suggested that the immunosuppression known to occur during negative emotional states, such as bereavement, depression [6, 7], or anger [8], and the immunoenhancement associated with positive emotional states [8, 9] may be mediated, in part, by the ANS [10]. It is also well recognized that music can alter mood and emotional states [11- 14]. However, few studies have examined the effects of music on the immune system [15, 16], and none have determined whether these effects are mediated by the ANS.
We investigated the effects of music on autonomic activity and immunity using power spectral density (PSD) analysis of heart rate variability (HRV). Changes in HRV have been used to characterize a number of psychological illnesses including major depression and panic disorders [17, 18], in addition to its use as a non-invasive test of integrated neurocardiac function [19]. Thus the mathematical transformation of heart rate variability into power spectral density provides a potential link between perception, emotional states, cardiovascular function and immunity. The interaction of mood, immunity and autonomic function has been highlighted by a number of studies showing that anger and hostility increase sympathetic activity [1, 20] and suppress immunity [8, 21], while positive emotional states, such as appreciation, enhance parasympathetic activity [2] and boost immunity [8, 22]. Scientific investigation of the use of music as a therapeutic modality began after World War II when its positive effects on emotionally disturbed, shell-shocked individuals were observed. Music therapy research has since demonstrated beneficial effects on the cardiovascular system [23], pain perception [24, 25] , stress [26, 27] and endocrine activity [28]. Music therapy has been shown to increase S-iga in hospitalized children after a single session [16], or after six weeks of ongoing therapy [29]. Anxiety associated with the stress of surgery was reduced after listening to music [26, 30], and music has been shown to decrease anxiety levels even in the absence of a specific stressor [31-33]. Music has not only been used to promote relaxation [14, 34-37], and improve mood [12, 38] but has also been employed in a wide variety of other medical settings [39]. The major difficulty in interpreting these data is that music was frequently used in conjunction with either relaxation therapy or guided imagery. Therefore it remains unclear to what extent music, by itself, can modify autonomic or immunological parameters. We have previously demonstrated that self-induced positive emotional states can alter sympathovagal balance [2] and increase S-iga [8]. In this study we assessed the effects of three different types of music including a new type of music called 'designer music,' which is reported by the composer to have a balancing effect on one's mental and emotional states. Specifically we investigated the effects of a single music session on autonomic function and S-iga and whether designer music could enhance the autonomic and immunological effects of positive emotional states in a synergistic manor.
