Neurohemodynamic correlates of ′OM′ chanting: A pilot functional magnetic resonance imaging study
Bangalore G Kalyani, Ganesan Venkatasubramanian, Rashmi Arasappa, Naren P. Rao, Sunil V Kalmady, Rishikesh V Behere, Hariprasad Rao, Mandapati K Vasudev, Bangalore N Gangadhar
International Journal of Yoga April 29, 2011 DOI: 10.4103/0973-6131.78171 (opens in new tab) via DOAJ
Summary
AI-generated from the abstractAudible 'OM' chanting produces a sensation of vibration that may stimulate the vagus nerve through its auricular branches. Using fMRI in 12 healthy volunteers, the neurohemodynamic correlates of 'OM' chanting were compared with pronouncing 'ssss' and with a resting state. 'OM' chanting caused significant deactivation bilaterally in the orbitofrontal, anterior cingulate, parahippocampal gyri, thalami, hippocampi, and right amygdala, with no significant activation. The 'ssss' condition showed no such changes. These limbic deactivations resemble those seen with vagus nerve stimulation used in depression and epilepsy, suggesting a potential clinical role for 'OM' chanting.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 12 |
| Population | Right-handed healthy volunteers (nine men) |
| Topics | Meditation |
| Key finding | Audible 'OM' chanting induced significant limbic deactivation similar to vagus nerve stimulation, while the control 'ssss' condition did not. |
Abstract
Background: A sensation of vibration is experienced during audible ′OM′ chanting. This has the potential for vagus nerve stimulation through its auricular branches and the effects on the brain thereof. The neurohemodynamic correlates of ′OM′ chanting are yet to be explored. Materials and Methods: Using functional Magnetic Resonance Imaging (fMRI), the neurohemodynamic correlates of audible ′OM′ chanting were examined in right-handed healthy volunteers (n=12; nine men). The ′OM′ chanting condition was compared with pronunciation of "ssss" as well as a rest state. fMRI analysis was done using Statistical Parametric Mapping 5 (SPM5). Results: In this study, significant deactivation was observed bilaterally during ′OM′ chanting in comparison to the resting brain state in bilateral orbitofrontal, anterior cingulate, parahippocampal gyri, thalami and hippocampi. The right amygdala too demonstrated significant deactivation. No significant activation was observed during ′OM′ chanting. In contrast, neither activation nor deactivation occurred in these brain regions during the comparative task - namely the ′ssss′ pronunciation condition. Conclusion: The neurohemodynamic correlates of ′OM′ chanting indicate limbic deactivation. As similar observations have been recorded with vagus nerve stimulation treatment used in depression and epilepsy, the study findings argue for a potential role of this ′OM′ chanting in clinical practice.