|Year : 2014 | Volume
| Issue : 3 | Page : 154-156
Electro-encephalographic changes of short-term transcendental meditation
Laishram Leimahanbi Chanu, Ksh Gomti Devi
Department of Physiology, Regional Institute of Medical Sciences and Hospital, Lamphelpat, Imphal, Manipur, India
|Date of Web Publication||5-Jan-2015|
Laishram Leimahanbi Chanu
Department of Physiology, Regional Institute of Medical Sciences and Hospital, Lamphelpat, Imphal - 795 004, Manipur
Source of Support: None, Conflict of Interest: None
Objective: We evaluated the effects of short transcendental meditation lasting ten minutes in untrained subjects. The changes in electroencephalogram (EEG), pulse rate (PR) and blood pressure (BP) were evaluated. Materials and Methods : EEG was taken after 10 minutes rest; during meditation with "AUM" chanting; and after 10 minutes of meditation, in 30 medical students. BP and PR were recorded after 10 minutes rest and after meditation. Results: The mean resting EEG was 38 Hz (range 32-48 Hz; SD: 4.3). During meditation, alpha waves were seen in 8 (26%) subjects, the rest had beta waves. The mean EEG during and after meditation were 24 Hz (range 8-35 Hz; SD 10.8) and 25 Hz (range 8-36 Hz; SD 10), respectively. The mean PR before and after meditation were 82/min (range 70-96; SD 6.6) and 74/min (range 68-88; SD 5.2), respectively, and the change was significant (P = 0.03). There was a significant drop in both systolic BP (P = 0.001) and diastolic BP (P = 0.002) following meditation. Mean systolic BP before and after meditation were 118 mm Hg (range 106-130; SD 7.4) and 112 mmHg (range 100-126; SD 7.3), respectively, and the mean diastolic BP before and after meditation were 74 mm Hg (range 60-82; SD 5.2) and 68 mmHg (range 60 - 82; SD 5.2), respectively . Conclusion: A significant reduction in PR and BP can be achieved with short transcendental meditation. Alpha waves consistent with meditative state could be achieved in 26% of the subjects.
Keywords: Blood pressure, EEG, meditation, mental stress, pulse rate
|How to cite this article:|
Chanu LL, Devi KG. Electro-encephalographic changes of short-term transcendental meditation. J Med Soc 2014;28:154-6
| Introduction|| |
Meditation offers a fascinating window into human consciousness, psychology and experience; their relationship between mental status and body physiology.  The word meditation is used to describe practices that self-regulate the body and mind, thereby affecting mental events by engaging a specific attention set.  In general, the outcome of the meditative process is associated with a sense of relaxation and positive mood with a feeling of benevolence towards oneself and others. 
Transcendental meditation is a mental stress reduction technique, which fits somewhat within the concentrative form as the practice centers on the repetition of a chant/mantra.  In transcendental meditation, the practitioner closes his eyes and silently repeats a mantra, a meaningless sequence of sounds specific to each individual to promote a natural shift of awareness to a wakeful but deeply restful state.  This technique is defined as turning the attention inwards towards subtlest levels of a thought until the mind transcends the experience of the subtlest state of the thought and arrives at the source of the thought. The technique involves no suggestion, mental control or physical manipulation. 
Numerous studies have reported changes in various brain rhythms, emphasizing the positive effects of meditative state as compared to any type of non-meditative state.  Most of these studies have indicated an overall slowing down of brain rhythm after meditation as well as some autonomic changes. Research data indicate that there are varying physiological correlation associated with meditation.  One likely contributing factor to the inconsistency across studies is the lack of standardization with respect to meditative style, assessment methodology and consideration of state effects for beginner vs. short term vs. long- term meditators.  Towards this end, the present study is designed to provide fundamental information using simple electroencephalogram (EEG) measures by a student's physiograph during meditation in subjects who have no prior knowledge/ practice of meditation.
| Aims and Objectives|| |
To compare the EEG patterns, blood pressure (BP) and pulse rate (PR) before, during and after meditation.
| Materials and Methods|| |
The study was conducted in the department of physiology, Regional Institute of Medical Sciences (RIMS), Manipur. A total of 30 medical students were enrolled for the study. Written and informed consent was taken. The study period was from, June 2012 to January 2013.
Inclusion and exclusion criteria
Subjects between the age group of 18 to 30 years were taken for the study. This included both males and females, with no prior use of any meditation techniques.
Those with history of seizure disorder or psychiatric illness were excluded from the study. Habitual alcohol drinkers were also excluded from the study.
The study was conducted in a moderately illuminated quiet room. The subjects sat erect on a comfortable mat. A suitable meditative posture of choice was adopted.
The first EEG electrode was attached to the mid forehead and the second to the mid occipital region. The ground electrode was attached to the mastoid region.
Preparation time lasted for 10 minutes. After stabilization, baseline BP, PR and EEG recordings were taken. The subjects then concentrated only on their surroundings and with their eyes closed in the meditative pose. The participants were instructed to inhale and exhale deeply while chanting "AUM" for several times during the meditative period. Meditation continued for 10 minutes during which EEG was recorded. Then they were allowed to rest for 10 minutes, after which PR, BP and EEG recording were done.
The instrument used for recording the EEG was Student's Physiograph of Recorders and Medicare Systems Pvt Ltd. The sampling frequency was 250 Hz and cutoff frequency was 50 Hz. Impedence was less than 10 KΩ for each electrode. Time constant was set at 0.3 seconds and the sensitivity at 0.1 mv. Single channel EEG machine was used for recording EEG.
For analytical purposes, statistical techniques like mean, standard deviation, t-test and correlation co-efficient are used whenever found suitable and necessary through Statistical Package for the Social Sciences software (SPSS software version 16), and accordingly the interpretations were made. A probability value of <0.05 was considered for statistical significance.
| Results|| |
The number of subjects enrolled in the study was 30. The median age was 22 years (range 18-29 years) and the male: Female ratio was 1.5:1. History of mental stress was presented in 6 (20%) patients. The baseline characteristics is as shown in [Table 1]. The PR dropped down significantly from a baseline median value of 82/minute to 74/minute, P = 0.03. Systolic and diastolic BP decreased significantly from 118 mm Hg to 112 mm Hg and from 74 mm Hg to 68 mm Hg after meditation (P = 0.001 and P = 0.002, respectively). The median baseline EEG was 38 Hz (range 32-48 Hz; SD 4.3). This significantly dropped down to 24 Hz during meditation. [Table 2] shows the PR, BP and EEG change before, during and after meditation. Alpha waves were seen in 8 (26%) subjects during meditation, but was absent during baseline or post-meditation period. The presence of alpha wave did not vary significantly with age, sex, body mass index (BMI) or the presence/absence of mental stress, as shown in [Table 3].
| Discussion|| |
0Significant slowing down of EEG wave rhythm was seen with the short-term meditation. This was consistent with the works of Tebesis. 
Previous studies of meditation by experienced subjects using multi-channel EEG have shown presence of Alpha and Theta waves during deep meditative state.
The EEG pattern during meditation showed predominance of alpha waves in a few subjects. In a study by Wallace,  the predominant EEG wave during meditation was alpha wave. The alpha waves were seen in 30% of the subjects in this study.
Many subjects displayed no or minor changes. Thus, pronounced and reliable physiological changes do not necessarily occur during transcendental meditation, as has been claimed. 
No theta or delta waves were seen. This may be due to the inexperience of the subjects or the short period of mediation. Earlier studies of the EEG during meditation by Indian yogis and zen practitioners also report considerable variation between individuals.  Achievement of meditative state did not differ by age, sex, BMI or the presence of mental stress.
Short-term meditation by previously untrained subjects significantly reduces both the systolic and diastolic blood pressure. This may be because transcendental meditation has been associated with the reduction in sympathetic nervous system tone, hypothalamic-pituitary-adrenocortical axis activation and cortisol level reduction.  Transcendental meditation has also been shown to reduce BP reactivity to acute behavioral stress in the laboratory setting.  There was also significant reduction in the PR.
| Conclusion|| |
Short-term meditation can have certain significant physiologic effects. Alpha waves consistent with the meditative state could be achieved in 30% of the subjects, which was detected using a simple instrument (Student's Physiograph).
A significant reduction in BP and PR can be achieved with the short duration of transcendental meditation.
The results seem to distinguish the state produced by transcendental meditation from commonly encountered states of consciousness and suggest that it may have practical applications especially in the life of medical students. But, we need to devote more time to meditation to achieve higher levels of mental relaxation.
| References|| |
Newberg AB, Iversen J. The neural basis of the complex mental task of meditation: Neurotransmitter and neurochemical considerations. Med Hypotheses 2003;61:282-91.
Cahn BR, Polich J. Meditation states and traits: EEG, ERP and neuroimaging studies. Psychol Bull 2006;132:180-211.
Aftanas LI, Golocheikine SA. Non-linear dynamic complexity of the human EEG during meditation. Neurosci Lett 2002;330:143-6.
Yamamoto S, Kitamura Y, Yamada N, Nakashima Y, Kuroda S. Medial prefrontal cortex and anterior cingulated cortex in the generation of alpha activity induced by transcendental meditation: A magnetoencephalographic study. Acta Med Okayama 2006;60:51-8.
Wallace RK. Physiological effects of transcendental meditation. Science 1970;167:1751-4.
Bhatia M, Kumar A, Kumar N, Pandey RM, Kochupillai V; EEG study; BAER study; P300 study. Electrophysiological evaluation of sudharshan kriya: An EEG, BAER, P300 study. Indian J Physiol Pharmacol 2003;47:157-63.
Cahn BR, Delorma A, Polich J. Occipital gamma activation during vipassana meditation. Cogn Process 2010;11:39-56.
Tebecis AK. A controlled study of the EEG during transcendental meditation: Comparison with hypnosis. Folia Psychiatr Neurol Jpn 1975;29:305-13.
Bagchi, BK, Wenger MA. Electrophysiological correlates of some Yogi exercises, Electroencephalogr Clin Neurophysiol 1957;7:132-49.
Kasamatsu A, Hirai T. An electroencephalographic study on the Zen meditation (Zazen). Folia Psychiat Neurol Jpn 1966;20:315-36.
Wallace RK, Benson H, Wilson AF. A wakeful hypometabolic physiologic state. Am J Physiol 1971;221:795-9.
Barnes VA, Treiber FA, Davis H. Impact of transcendental meditation on cardiovascular function at rest and during acute stress in adolescents with high normal blood pressure. J Psychosom Res 2001;51:597-605.
[Table 1], [Table 2], [Table 3]