Effects of music on gastric myoelectrical activity

Electrogastrography (EGG) is an attractive noninvasive method for investigating gastric motility, still it has not gained a role in the clinical routine. On the other hand, music therapy is spreading in the care of pain and anxiety although the pathophysiological route of its effectiveness has not been elucidated. The demonstration of changes in gastric myoelectrical activity while listening to music by Lin et al. (1) may therefore open new issues in the research of both fields.

The authors found that the power of the gastric myoelectrical activity increased in the persons when they were listening to some music they enjoyed but on the contrary the power of the gastric myoelectrical activity decreased in those who listened to the same music but did not enjoy it. They conclude that music therapy may be used to stimulate gastric emptying. As the study was carried out only in fasting state although the registration of the gastric myoelectrical activity after a standard meal is the important part of the EGG examination (2), this conclusion seems to be premature. We would like to show our results to reach a more detailed opinion.

Electrogastrography was performed for two groups of eight healthy young adult volunteers. Group 1 underwent two EGGs, once in silence and once while listening to a self-chosen relaxing music. Group 2 underwent two EGGs, once while listening to Mozart and once while listening to a hard rock mix. Registrations were done with a Synectics HR 8 channel Polygraph (Synectics, Stockholm, Sweden). After 30 min registration in fasting state people got a standard meal (400 kcal) and drink (2 dl) and the registration was continued for 60 min. Period dominant power, period dominant frequency and percentage of bradygastria (< 2.4 cycle/min), normal rhythm (2.4–3.6 cycle/min) and tachygastria (> 3.6 cycle/min) were calculated with the software provided by the manufacturer after the careful visual analysis of the raw records.

In group 1, tachygastria was significantly lower in the fasting state while listening to music compared with registration in silence (11% vs. 25%, p < 0.03). The other parameters showed a tendency of slower dominant frequency under music listening without being statistically significant. In group 2, we could not find any significant change in the observed parameters.

These results suggest three important observations. First, the slowing of gastric myoelectrical activity while listening to music in fasting state confirms the public opinion about the relaxing effect of music. Secondly, the absence of change in gastric myoelectrical activity upon music after eating suggests that music does not play any role in gastric emptying. Thirdly, the findings of Lin et al. (1) suggest that the effect of music depends on the preference of the person. It may explain why our original hypothesis that Mozart would have a slowing and hard rock an accelerating if any effect on gastric myoelectrical activity was not correct. After the study, it turned out that all but two young participants preferred rock to Mozart.