Detrended Fluctuation Analysis of the Brain Activities Related to Chanting Amitofo: A Scale-free Eeg Study

Abstract

Detrended fluctuation analysis of the brain activities related to chanting Amitofo: a scale-free EEG study Dr. Junling Gao, Centre of Buddhist Studies, The University of Hong Kong Background: Neuroimaging studies usually describe the average of brain activities while discard the variability. However, converging evidence shows that the neural signals are scale-free and contain long-term autocorrelations and 1/f structure. Detrended fluctuation analysis (DFA) can capture these features in neural signals. Our previous EEG study on religious chanting can reduce the late-positive potential induced by negative pictures. In this study, we aimed to use DFA to explore the brain activities during chanting Amitofo, a most popular Buddhism practice in East Asia. Method: Twenty-one participants with at over one year of chanting Amitofo experience were recruited. The resting-state EEG data were collected by 128-channel EGI system, with four conditions: chanting Amitofo, chanting Santa Claus, mindful breathing, no chanting, and each condition last for 10 minutes. All conditions including chanting were kept silently with eyes-closed. The EEG data were preprocessed by EEGlab for artefact reduction and filter. The DFA was calculated by NBT toolbox (www.nbtwiki.net) based on Matlab. Results: It showed that chanting Amitofo induced highest delta band (1-4Hz) DFA around the posterior cingulate cortex (PCC), whereas mindfulness breathing induce higher delta band DFA in the left dorsal lateral prefrontal. Conclusion: DFA can measure the scale-free feature and capture additional information of neural signals alteration during religious chanting of Amitofo. It demonstrated that religious chanting could induce stronger long-range temporal correlation in posterior brain regions, probably related to visualization during religious chanting.