The role of brainstem in affect modulation during repetitive religious chanting.

Abstract

Introduction: Repetitive religious chanting is a most common practice in Mahayana Buddhism. It is assumed that the repetitively chanting the name of Amitabha Buddha can bring joyousness and calm to the practitioner. This functional magnetic resonance imaging (fMRI) study aimed to investigate the underlying neuro-mechanism of religious chanting in affective modulation. Method: Eighteen participants with more than one year of practice in religious chanting of Amitabha Buddha volunteered to do the fMRI experiment. The fMRI study was Human Research Ethics Committee at the University of Hong Kong. In the fMRI study on affective modulation is a 2x3 design, with two types of fearful and neutral pictures, three chanting conditions of religious chanting, non-religious chanting and no-chanting. A serial of fearful pictures was shown to the participants, and they were asked to viewing these pictures while repeating religious chanting of Amitabha’s name. Similarly, other conditions included neutral pictures and/or other chanting conditions. Totally there were six conditions which last 20 seconds. The sequences of these conditions were randomized. The MRI data were collected by a 3 T Philips MRI Scanner. The data were analyzed by SPM12, following its routine procedures. A flexible design was used in the second-level data analysis. Results: The results showed that the repetitive religious chanting induced more brain activities in the bilateral fusiform, medial frontal and subcortical regions including the brainstem, amygdala, thalamus when viewing the fearful pictures, as compared to viewing neutral pictures. Further comparison with non-religious chanting and no-chanting condition showed the brainstem; roughly the pons area is significantly activated during religious chanting. Conclusion: Religious chanting can significantly change the brain activities but only when viewing the fearful pictures. The brainstem, specifically the pons plays an important role in affection modulation induced by religious chanting. The interaction between fearful situation and religious chanting deserve future studies which may imply new ways of emotion regulation.