top of page

Neuro-hemodynamic effects of mantra recitation  "OM"




Authors: Bangalore G Kalyani, Ganesan Venkatasubramanian, Rashmi Arasappa, Naren P Rao, Sunil V Kalmady, Rishikesh V Behere, Hariprasad Rao, Mandapati K Vasudev, Bangalore N Gangadhar

Department of Psychiatry, Center for Advanced Yoga, National Institute of Mental Health and Neuroscience, Bangalore, Int J Yoga - 560 029, India


The opinion of the authors of the article may not correspond with the opinion of the editorial staff of the site (but we do not argue with the facts)





Background : During the recitation (chanting) of the mantra “OM” a feeling of vibration affects the stimulation of the vagus nerve through its ear branch and thus realizes the impact on the brain. The neuro-hemodynamic effects of the mantra "OM" have not yet been studied.


Materials and Methods: Neuro-hemodynamic effects of mantra 'OM' were studied in nine healthy men and three right-handed women (n = 12) using functional magnetic resonance imaging (fMRI). The effects after chanting the mantra "OM" were compared to pronouncing the sound "ssss". The analysis was performed using Statistical Parametric Image 5 (SPI5).


Results : In this study, during the chanting of the mantra "OM", a significant deactivation (changes in brain activity compared to the resting state) was observed in different parts of the brain : orbito-frontal, cingulate cortex anterior, parahippocampal gyrus, hippocampus, and thalamus. 

The right cerebellar amygdala also showed a significant decrease in activity.  


During the chanting of the mantra "OM" no significant activation was observed. And when pronouncing the sound "ssss", on the contrary, neither activation nor deactivation occurred in these parts of the brain.


Conclusion : The neuro-hemodynamic effects of mantra chanting "OM" testify to limbic deactivation. Since similar observations have been reported under the action of the vagus nerve, which is used to treat depression and epilepsy, the study results suggest a potential role for chanting the 'OM' mantra in clinical practice.



Vagus nerve stimulation is used in the treatment of depression, and epilepsy. Studies with positron emission tomography (PET) [3] have shown a reduction in blood flow in the limbic area of the brain during the line of electrical stimulation of the vagus nerve. Other studies using functional magnetic resonance imaging [4] have shown prominent limbic areas outside the brain during vagus nerve stimulation through the skin. In this procedure, an electrical impulse acts inside the left tragus - and thus the ear branch of the vagus nerve.


It is widely known to use the mantra "OM" in meditation practices [5]. Chanting the mantra "OM" creates a feeling of vibration around the ears. It is also considered that these sensations associated with the transmission of impulses through the intermediate branch of the ear to the vagus nerve. We hypothesized that chanting "OM" will cause similar neuro-hemodynamic effects off the limbic areas of the brain, amygdala, hippocampus, parahippocampal, thalamus, orbitofrontal and anterior cingulate cortex, as revealed it in the previous study [5].



Materials and methods

The study involved nine healthy, right-handed men and three women (n=12), who agreed to enter the MRI study as participants. Two qualified psychiatrists independently evaluated these volunteers to prevent: 1) psychiatric diagnoses, 2) family history of serious mental illness in the first generation, 3) pregnancy or postpartum condition 4) substance abuse or addiction , 5) severe neurological disorder, 6) any contraindication to MRI, 7) clumsiness. 

The absence of psychiatric illnesses was established thanks to a special MINI survey (Mini international neuro-psychiatric interview plus) [5]. The age range of the subjects was 22-39 years (mean ± SD = 28 ± 6 years). All participants had an education. Four of the study participants underwent formal yoga training, including meditation, for the rest this technique was new. The study protocol was verified by the ethics committee of the National Institute of Mental Health and Neurology. In addition to the consent for the current study, which has already been given by the subjects, they received the results of the current FMRT, and were taught to chant the mantra OM before proceeding with the new FMRT survey.



Participants were trained to chant the mantra "OM" with an experienced yoga teacher. An important condition is the absence of fatigue and breaks. The vowel "O" sang for 5 seconds, and for another 10 seconds - the consonant "M" . In the electro-physiological studies conducted earlier, the mental chanting of the mantra "OM" was used, in this study the chanting of the mantra was chosen aloud. This provided objective confirmation of task accomplishment during FFMT, as well as ensuring vibration sensitivity and vagus nerve stimulation through the ear canals. 

The state of control was the reproduction of the sound "  ssss  »  for the same duration (15 seconds). The sound "ssss" was chosen for comparison with the exhalation while chanting the mantra "OM", but without the sensation of vibration around the ears. Both practices were performed in the supine position. Similarly, all study participants were familiar with performing the task in the MRI tube.



At the end of the mission, one of the researchers established that the subjects felt the vibration only during the chanting of "OM", but not with the sound "  ssss  »  .

The FFMT procedure consisted of several blocks. The steps of the experiment: 1) first a high-resolution structural study of the brain 2) followed by a series of echoplane imaging (EPO), in which the level of oxygen in the blood was analyzed . Echoplane imaging was repeated every 3 seconds. Within 10 minutes, 200 EPO exams were performed. These 10 minutes were made up of "OM" and "sss" blocks of 15 seconds. These blocks were mixed with 15 second rest periods. In total there were 10 OM blocks, 10"  ssss  and 20 rest blocks [Figure 1].



Figure 1. 1 cycle: "Rest-"OM"-Rest-"sss", 10 cycles were performed by each subject during the FFRI test.

Image sequence

The visualization was carried out through the MRI scanner (3 Tesla) of the National Institute of Mental Health and Neurology. This high-resolution structural image was used to locate activation of brain regions, as well as to rule out significant brain abnormalities in the subjects. The total duration of echoplane imaging was 10 minutes. During echoplane imaging, subjects alternated between different states (such as "OM", "  ssss" and "rest") every 15 seconds (as described above) , via an MRI compatible monitor synchronized with the image obtained by means of e-prime software, built in the eloquence fMRI hardware installation.


Image analysis

MRI analysis was performed for all patients using Parametric 5 Conversion (SPP5) statistics ( Images were adjusted for variations in cut-off time and normalized [7, 8, 9], as well as smoothed with an 8 mm filter core width at half maximum full power.


Table 1. Areas of the brain with significant deactivation during chanting "OM" compared to the state of "  REST".


Compared to resting state, oxygen level in blood parameters showed no significant fMRI brain activation while chanting “OM”. However, while chanting "OM", significant deactivation was observed in the amygdala, parahippocampal gyrus, hippocampus, brain island orbitsphere frontal cortex, parahippocampal gyrus, and thalamus [Table 1] and [Figure 2]. Pronouncing the sound "ssss" did not cause significant activation/deactivation in any of these brain areas.



The Talairach frame of reference is a coordinate system for pinpointing the position of any point in the brain

Figure 2. Compared to rest, chanting “OM” causes deactivation of the thalamus (A) and limbic structures - the anterior part of the cingulate gyrus (B), hippocampus (C), brain islet (D) and the parahippocampus (E). Whereas the control state - the pronunciation of the sound "ssss" - did not cause any deactivation in any of these regions (F). The color bar represents the T-test values shown in the table.


Compared to the resting state, in this study, there is a significant deactivation in both hemispheres of the brain during the chanting of “OM”:  in the frontal orbitsphere, the anterior cingulate cortex, the parahippocampal gyrus, the hippocampus and the thalamus. Furthermore, the right cerebellar amygdala also showed significant deactivation. No significant activation was observed during the chanting of "OM". 

In contrast, activation or deactivation occurred in these brain areas during the search for states comparing - namely, to the pronunciation of "ssss".


Although the effect of 'OM' repetition on the hemodynamic response of the brain has been demonstrated, in one study, Kraus et al. [4] investigated the effect of electrical stimulation of vagus nerve branches through the skin to change blood oxygen levels using fMRI. Due to the involvement of the vagus nerve (as proposed in the study), we compared our study with the first [4].


It is interesting that our research results are consistent with the previous one. Using a different methodology (positron emission tomography), other researchers have shown reductions in blood flow to both sides in the hippocampus, amygdala, and isthmus cingulate gyrus extending from the left side of the spine. cervical spine in patients with epilepsy with vagus nerve stimulation. Similarly, treatment of vagus nerve stimulation in patients with depression decreases regional cerebral blood flow in the amygdala, left hippocampus, subgenual anterior cingulate cortex to the left front of the ventral cingulate on both sides , the right side of the thalamus and the brainstem, as measured by single photon emission computed tomography [13].  


Interestingly, these brain regions are overactive in patients with depressive disorders [14], for whom vagus nerve stimulation is used as therapy. However, our observations supporting for vagus nerve stimulation as a mechanism of "OM repeat" are preliminary, and further research is needed to confirm our hypothesis.


Alternatively, chanting "OM" can be a means of relaxation. Since meditation, as shown in the test, it (OM) activates the structures involved in the relaxation response, namely the front girdle cortex, parietal and prefrontal cerebral cortex, hippocampus and temporal lobes [15], we cannot not exclude the mixed effect of relaxation.


Thus, the hemodynamic effects of "OM" chanting indicate limbic deactivation. Given that similar observations have been reported using Ibn-therapy (vagus nerve stimulation) used in depression and epilepsy, the clinical value of repeating
  "OM" deserves further investigation.





List of literature used:  


1. Nahas Z, Marangell LB, Husain MM, Rush AJ, Sackeim HA, Lisanby SH, et al. Two-year outcome of vagus nerve stimulation (VNS) for treatment of major depressive episodes. J Clin Psychiatry 2005;66:1097-104. [PUBMED]   [FULLTEXT]


Jobst BC. Electrical stimulation in epilepsy: Vagus nerve and brain stimulation. Curr Treat Options Neurol 2010;12:443-53. [PUBMED]   [FULLTEXT]


Henry TR, Bakay RA, Pennell PB, Epstein CM, Votaw JR. Brain blood-flow alterations induced by therapeutic vagus nerve stimulation in partial epilepsy: II, prolonged effects at high and low levels of stimulation. Epilepsia 2004;45:1064-70. [PUBMED]   [FULLTEXT]


Kraus T, Hosl K, Kiess O, Schanze A, Kornhuber J, Forster C. BOLD fMRI deactivation of limbic and temporal brain structures and mood enhancing effect by transcutaneous vagus nerve stimulation. J Neural Transm 2007;114:1485-93.


Kumar S, Nagendra H, Manjunath N, Naveen K, Telles S. Meditation on 'OM': Relevance from ancient texts and contemporary science. Int J Yoga 2010;3:2-5. [PUBMED]


Sheehan DV, Lecrubier Y, Sheehan KH, Amorim P, Janavs J, Weiller E, et al. The Mini-International Neuropsychiatric Interview (MINI): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry 1998;59:22-33;quiz 4-57.


Friston K, Ashburner J, Frith CD, Poline JB, Heather JD, Frackowiak RS. Spatial registration and normalization of images; 1995.


Venkatasubramanian G, Hunter MD, Wilkinson ID, Spence S. Expanding the response space in chronic schizophrenia: The role of left prefrontal cortex. NeuroImage 2005;25:952-7.


Venkatasubramanian G, Spence SA. Schneiderian first rank symptoms are associated with right parietal hyperactivation: A replication using fMRI. Am J Psychiatry 2005;162:1545. [PUBMED]   [FULLTEXT]


Evans A, Collins DL, Mills SR, Brown RD, Kelly RL, Peters TM. 3D statistical neuroanatomical models from 305 MRI volumes. IEEE Nucl Sci Symp Med Imag Conf Proc 1993;108:1877-8.


Maldjian J, Laurienti PJ, Kraft RA, Burdette JH. An automated method for neuroanatomic and cytoarchitectonic atlas-based interrogation of FMRI data sets. Neuroimage 2003;19:1233-9.


Talairach P, Tournoux JA. A Stereotactic Co-Planar Atlas of the Human Brain. Thieme; 1988.


Zobel A, Joe A, Freymann N, Clusmann H, Schramm J, Reinhardt M, et al. Changes in regional cerebral blood flow by therapeutic vagus nerve stimulation in depression: An exploratory approach. Psychiatry Res 2005;139:165-79. [PUBMED]   [FULLTEXT]


Malhi GS, Lagopoulos J, Ward PB, Kumari V, Mitchell PB, Parker GB, et al. Cognitive generation of affect in bipolar depression: An fMRI study. Eur J Neurosci 2004;19:741-54. [PUBMED]   [FULLTEXT]


Lazar SW, Bush G, Gollub RL, Fricchione GL, Khalsa G, Benson H. Functional brain mapping of the relaxation response and meditation. Neuroreport 2000;11:1581-5. [PUBMED]   [FULLTEXT]



bottom of page