The Influence of Musical Rhythm on Cardiovascular, Respiratory, and Electrodermal Activity Dissertation zur Erlangung des Doktorgrades der Philosophie (Dr. phil.) vorgelegt der Philosophischen Fakult¨at der Martin-Luther-Universit¨at Halle-Wittenberg, Institut f¨ur Musik, Abteilung Musikwissenschaft von Martin Morgenstern geboren am 3. Juni 1979 in Dresden Gutachter: Professor Dr. Wolfgang Auhagen Martin-Luther-Universit¨at, Halle-Wittenberg Professor Dr. med. Hans-Christian Jabusch Hochschule f¨ur Musik Carl Maria von Weber, Dresden Tag der Verteidigung: 7. Juli 2009 iii Abstract Background. Athanasius Kircher, one of the first prominent figures to pro- pose a connection between the distinct rhythm of the heart and the state of people’s health, suggested the use of rhythmic stimuli to cure diseases. Since then, there have been various attempts to alter the heart rate by means of auditory stimuli, and for similar purposes. Be it in music or in rhythmical coordination tasks, interactions of periodic exogenous pulses and endogenous biological rhythms have been studied extensively. However, there are still limitations to understanding the regulating mechanisms in cardio-respiratory synchronisation. Aims. Various listening and bio-feedback experiments are discussed, dealing with different aspects of the influence of rhythmical auditory stimuli on cardio-respiratory regulation, biological rhythm generation and coordina- tion. A focus is on the interpretation of respective physiological adaptation processes and different relaxation strategies that might help musicians to deal with unwanted stress before, during, and after a musical performance. Dif- ferent challenges inherent to empirical musicological and music-related bio- medical research, and how they might be tackled in future experiments, are considered. The study itself aims to shed light on basic functions within the complex psycho-physiological regulatory mechanisms of subjects who are pre- sented with auditory stimuli. In different experiments, the author investigates heart rate behaviour under fixed pulse respiration ratios and during volun- tary breathing phases, the effects of rhythmical acoustic stimuli on subjects’ cardio-respiratory regulatory mechanisms, and the influence of bio-feedback on the ability to actively adapt and deflect their own heart rate to and from a steady periodic rhythmical stimulus. A set of questionnaires accompanies the experiments, providing information about musical preferences, learning issues, stage anxiety biases, and similar parameters that might contribute to a more comprehensive understanding of how subjects react to certain acoustic stimuli. Methods. Thirty-five volunteers participated in the investigation. Before the experiments took place, the subjects completed two questionnaires that covered age, gender, musical education and practises, daily rehearsal dura- tion, musical preferences, and overall expressivity. According to their musical practises and education, they were classified as musicians or controls after the experiments had taken place. When the ECG electrodes, a respiration belt, EDA electrodes and headphones had been applied, the subject’s ECG was monitored visually until a steady state was reached. The set of experiments started with a one-minute stimulus-reaction test to normalise the subject’s overall state of arousal and identify their physiological parameters at rest. A thirty minute listening experiment followed, during which the subjects lis- tened to a five minute musical sample three times, with five minute phases of silence before each musical sample was played. With every phase, the sub- iv ABSTRACT ject received different breathing instructions. After two phases of voluntary breathing, different pulse-respiration ratios had to be maintained with the help of visual ECG feedback. The subjects were instructed to listen atten- tively since a questionnaire about the musical and interpretational features of the musical sample had to be completed afterwards. This questionnaire con- tained questions about subjects’ state of arousal, involvement, and preference. When it had been completed, subjects were instructed on how to raise their heart rate by imagining stressful situations, such as a concert or an exam. A fifteen-minute experiment followed, with the subject listening to 150 seconds of metronome beat (with its frequency constantly adjusted to the subject’s obtained heart rate at rest), alternating with 150 second phases of silence. With every phase, the subject received different instructions on how to adapt or detach their heart rate (which was fed back visually and acoustically) to or from the metronome beat. Results. MATLAB data acquisition and a proprietary software tool was used to analyse the recorded physiological data sets, according to po- tential activation, coordination, and synchronisation effects of heart, respi- ration and electrodermal activity with the respective musical or rhythmical stimuli. These analyses and the information gathered in the questionnaires provided the documentation of the different psycho-physiological reactions to stress upon which this study is based. Subjects in both the musicians and the control groups increased breathing frequencies when listening to both slow or activating music compared to silence. Differences in average respiration rate were higher in musicians compared to controls. Whereas the difference in elec- trodermal activity was small in controls, musicians showed an average increase of 10.1 % ± 3.492 from slow to fast music. However, the alterations of heart frequency while listening to activating or sedating music were not significant, although the questionnaires account for high subject involvements. The results of the second experiment showed that subjects were able to actively increase their heart rates (compared to their heart rates at rest) with the help of bio- feedback; while, at the same time, their electrodermal activity increased. An external acoustic stimulus (a regular metronome click) did not significantly facilitate or counteract this ability. Regarding the coordination of heart and respiration, the analysis revealed that although the subjects’ respiration rates increased significantly during the phase when activating music was played, their heart rates did not. Thus, in the complex cardio-respiratory regulatory system, the parameters of heart frequency and respiration frequency seemed to function relatively independently, although coordination and synchronisation effects might have been occurring. An investigation into heart rate variability suggested that heartbeats became more regular when the subjects listened to music. However, that the decrease of heart rate variability is time-dependent, namely that subjects’ heart rates became more regular over the course of the experiment regardless of whether any music was played to them, cannot be v ruled out since the experimental setup did not always allow a control for ha- bituation effects. Additional analyses revealed that the more severely subjects rated their stage anxiety, the higher were their average heart rates and res- piration rates during the stimulus reaction test. An analysis of the results of an Affective Communication Test (ACT) revealed no significant differences between musicians and controls. However, the higher subjects scored in the test, the more intensely they rated their experience of the music. Implications. The mechanisms though which auditory stimuli can in- fluence biological rhythms are complex and cannot be easily modelled. For a durable understanding of the influences auditory stimuli have on the car- diovascular and respiratory cycle, studies have to investigate biophysical and psycho-physiological determinants (phase transitions, possible synchronisation and coordination effects, cardiac and respiratory arrhythmias and their causes, and psycho-acoustic impacts), group interactions, musical preferences and so on, in order to form a picture that might help improve the techniques used in applied music therapy, or develop relaxation techniques for musicians. Ap- plied music therapy could be more beneficial if a reliable understanding of how rhythmic stimuli influence the cardio-respiratory system existed, and if there were medical standards in interpreting heart and respiration activity in phases of physical activity, such as musical performances. Dank Zuallererst geb¨uhrt Prof. Dr. Wolfgang Auhagen und Dr. Dirk Hoyer Dank f¨ur ihre Anregungen auf dem Gebiet der Musikpsychologie einerseits, der Medizin andererseits. Mit ihrer Hilfe konnte das Thema ausgewogen von allen Seiten beleuchtet werden. Prof. Dr. med. Hans-Christian Jabusch und Prof. Dr. med. Eckart Altenm¨uller haben mir zahlreiche wertvolle Hinweise gegeben. Prof. Dr. Veronika Busch, Dr. Kathrin Schlemmer, Dr. Clemens W¨ollner, Dr. Frede- rik Nagel und Dr. Oliver Grewe m¨ochte ich f¨ur ihre Anregungen u. a. zur technischen Durchf¨uhrung der Experimente danken. Den Teilnehmern des Hallenser Tutoriums “Psychophysiologische Aspekte des Musikh¨orens”, den Kommilitonen und Kollegen im Doktoranden- kolloquium und den Teilnehmern der Arbeitstagungen der Fachgruppe Syste- matische Musikwissenschaft in der Gesellschaft f¨ur Musikforschung verdanke ich ebenfalls viele Ideen zur Durchf¨uhrung. Im Rahmen ihrer Diplom- oder Studienarbeiten haben Dipl.-Ing. Jes´us Araguzo Rivera, Valentin Reuter und Marko Goldhardt zum reibungslosen Aufbau der Experimente beigetragen und mich bei der Durchf¨uhrung der Versuche unterst¨utzt. F¨ur die Erstellung bzw. Anpassung