(58)

REVIEW OF LITERATURE

EFFECT OF MEDITATION ON VARIOUS BODY SYSTEMS

A review of the scientific literature on meditation reveals that practice of

meditation can endowed with various benefits regarding physical, mental and

emotional health. Meditation can reduce stress and anxiety, enhance motor

reflexes, improve motor control, boost tolerance, sharpen perceptions,

enhance awareness, advance concentration, preserve good health, provide a

general positive outlook on life and help us to get control over passions. In

general, meditation produces a change in multiple biological systems resulting

in a state of relaxation. Most of the studies reveal the effects are significantly

different between meditating and non-meditating groups.

EFFECT OF MEDITATION ON RESPIRATORY SYSTEM

Wolkove et al (1984) considered the effect of transcendental meditation on

breathing using 16 experienced meditators and 16 control subjects. In

controls, there was no significant difference in minute ventilation (i.e. amount

of air a person breaths in a minute), respiratory pattern and hypercapnic

response, whether breathing with eyes open-awake or with eyes closed-

relaxing. In meditators, minute ventilation decreased significantly during quiet

breathing from 14.0 +/- 0.7 1/min with eyes open-awake (MA) to 12.4 +/- 0.6

1/min during meditation (p < 0.02). The change in ventilation during

meditation was due to a decrease in tidal volume resulting from a shortened

inspiratory time. They found meditation was linked with a decreased response

(59)

to progressive hypercapnia from 3.7 +/- 0.4 to 2.5 +/- 0.21 X min-1 X Torr-1

during meditation trials, respectively (p < 0.01). These observations suggest

that an alteration in wakefulness, more subtle than sleep or the unconscious

state, can significantly affect the chemical and neural regulation of breathing.

Vyas et al (2002) studied respiratory functions, cardiovascular parameters and

lipid profile of those practicing Raja Yoga meditation (short and long term

meditators) and compared with those of non-meditators. Vital capacity, tidal

volume and breath holding were significantly higher in short and long term

meditators than non-meditators. Long term meditators had significantly

higher vital capacity and expiratory pressure than short term meditators.

Diastolic blood pressure was significantly lower in both short and long term

meditators as compared to non-meditators. Heart rate was significantly lower

in long term meditators than in short term meditators and non-meditators.

Lipid profile showed a significant lowering of serum cholesterol in short and

long term meditators as compared to non-meditators. Lipid profile of short

and long term meditators was better than the profile of non-meditators in

spite of similar physical activity. This shows that meditation provides

significant improvements in respiratory functions, cardiovascular parameters

and lipid profile.

MEDITATION AND CARDIOVASCULAR FUNCTIONS

Zamarra et al (1996) observed that meditators have a general increased

exercise tolerance and maximal cardiac workload as compared to non-

meditators.

Richmond et al (2000) found decreased carotid artery wall thickness after six

to nine months of application of Transcendental Meditation compared to

(60)

matched control subjects. This regression was similar to that achieved by

some lipid-lowering drugs and extensive lifestyle changes.

Paul et al (2006) studied effect of transcendental meditation on the

components of metabolic syndrome and found the group performing

meditation had beneficial changes (measured as mean ± SD) in adjusted

systolic blood pressure (−3.4 ± 2.0 vs 2.8 ± 2.1 mm Hg; p = .04), insulin

resistance (−0.75 ± 2.04 vs 0.52 ± 2.84; p = .01), and heart rate variability (0.10

± 0.17 vs −0.50 ± 0.17 p = .07) compared with the health education group,

respectively. There was no effect on brachial artery reactivity testing but there

was improvement in blood pressure and insulin resistance components of the

metabolic syndrome as well as on cardiac autonomic nervous system tone

compared with a control group receiving health education. These results

illustrates that transcendental meditation may modulate the physiological

response to stress and improve coronary heart disease risk factors.

Ospina et al (2007) identified five broad categories of meditation practices

(Mantra meditation, Mindfulness meditation, Yoga, Tai Chi and Qi Gong) and

studied three conditions; hypertension, other cardiovascular diseases, and

substance abuse. Meta analyses based on low quality studies and small

numbers of hypertensive participants showed that Qi Gong and Zen Buddhist

meditation significantly reduced blood pressure. Yoga helped in reducing

stress. Yoga was no better than mindfulness-based stress reduction at

reducing anxiety in patients with cardiovascular diseases. Meta analyses of

results from 55 studies indicated that some meditation practices produced

significant changes in healthy participants.

(61)

Ankad et al (2011) found significant reduction in resting pulse rate, systolic

blood pressure, diastolic blood pressure, and mean arterial blood pressure

after practicing pranayama and meditation for 15 days. The response was

similar in both the genders, both the age groups, <40 years and >40 years and

both the groups with BMI, <25 kg/m and >25 kg/m. This study showed

beneficial effects of short term (15 days) regular pranayam and meditation

practice on cardiovascular functions irrespective of age, gender and BMI in

normal healthy individuals.

MEDITATION AND METABOLISM

Anand (1961) studied a yogi in India who could lower his oxygen metabolism

at will. A similar report was found of Zen monks in Japan who could reduce

their oxygen consumption by 20% during meditation sessions.

Wallace et al (1971) found that during the practice of meditation the amount

of carbon- dioxide elimination drops in proportion to the amount of oxygen

consumed without change in the respiratory quotient. They concluded that

the metabolic changes of meditation arise from a natural reduction in

metabolic activity at the cellular level, not from a forced reduction of

breathing.

Farrow and Herbert (1982) found a greater 40% decline in oxygen

consumption at a 50% decline in respiration rate following TM. Kesterson and

Clinch (1989) in a comprehensive study reported reduced sensitivity to CO2

during meditation.

Benson et al (1990) studied effect of meditative practices on body

metabolism and the electroencephalogram (EEG) and they noted resting

(62)

metabolism (VO2) could be both raised (up to 61%) and lowered (down to

64%) during the practices. The reduction when performing rest was the

largest ever reported. On the EEG, marked asymmetry in alpha and beta

activity between the hemispheres and increased beta activity were present.

Hence it was concluded that advanced meditative practices may produce

different alterations in metabolism.

Jevning et al (1996) exemplify a noticeable rearrangement in the blood flow

of meditators. Blood flow to the kidneys and liver decreases in practitioners

with a surprising increase in cardiac output. The increment in cardiac output

and decrement in blood flow towards kidneys and liver shows that most of the

distributed circulation must be to the brain. The redistribution of blood flow

with an increase in cardiac output has interesting significance for the pattern

of metabolic changes brought by meditation; although the response to

meditation is hypo metabolic overall, it shows possibility that there is a

simultaneous increase in the metabolism of certain tissues.

These changes, as reported in above studies, suggest that meditation is a

hypometabolic state, though similar to sleep or rest, but have unique

psychophysiological patterns. The studies of organ, tissue, and cellular

changes during meditation have become more popular in recent years,

primarily with long-term meditators in 30-40 minute sessions (Jevning 1992).

One common finding is a decline in arterial lactate levels (Jevning et al 1978,

Solberg 2000, Wilson et al 1987). A 20% increase in phenylalanine

concentrations was found in another study (Jevning 1977), compared with

insignificant blood level changes in 12 other amino acids. Although the

reasons for metabolic the changes during meditation are often unclear, they

(63)

seem to be related to a specific hypometabolic functioning unrelated to sleep

or other rest states.

MEDITATION AND AUTONOMIC NERVOUS SYSTEM

Orme-Johnson (1973) used galvanic skin response (GSR) to measure recovery

from stress showed that meditators recovered from stress more quickly than

non-meditators. Specifically, habituation of the GSR to stress was faster for

meditators than for controls and meditators made fewer multiple responses

during habituation, indicating greater stability in response to stress.

Schwartz (1975) found meditation produces specific neural activation

patterns involving decreased limbic arousal in the brain. Limbic system

contains the hypothalamus which controls the autonomic nervous system and

reduction in limbic arousal explain how meditation reduces stress and

increases autonomic stability to stress. Ultimately meditation strengthens and

enhances the ability to cope with stress.

Telles and Desiraju (1993) presented the changes in various autonomic and

respiratory variables during the practice of Brahmakumaris Raja Yoga

meditation. They showed that the heart rate during the meditation period was

increased compared to the preceding baseline period, as well as compared to

the value during the non-meditation period of control sessions. In contrast to

the change in the heart rate, there was no significant change during

meditation, for the group as a whole, in palmar GSR, finger plethysmogram

amplitude, and respiratory rate.

Yang et al (2009) examined the effects of meditation on the physical and

mental health of junior college students and found meditation to produce

(64)

positive and demonstrable stress reduction effects on brain and immune

functions. Their findings showed that the effect of the experiment treatment

was significant when student’s physical and mental distress pre-test scores

were controlled. Physical and mental symptoms in the experimental group

were lower than those in the control group. This study also promotes

meditation as one way to improve health.

MEDITATION AND SKIN TEMPERATURE

Manocha et al (2010) studied decreased mean skin temperature of the Sahaja

Yoga meditation group and compared with control group. After ten minutes of

meditation, 13 of the 16 meditators manifested a reduction in skin

temperature compared to baseline whereas 7 of the 10 participants in the

control group manifested an increase compared to baseline.

MEDITATION AND ENDOCRINE SYSTEM

The few biochemical studies conducted so far are suggestive of changes in

neurotransmitters, hormonal, immunological and stress responses. The neuro-

endocrine and immune systems are known to be influenced by the

psychosomatic interactions. A mutual regulation exists between the neuro-

endocrine and immune systems; the neuro-endocrine system influences

immune function through hormonal and neural pathways while the immune

system affects neuro-endocrine function by means of cytokines.

Wallace (1970) identified a number of endocrine reactions in the meditative

response pattern, including reduced blood levels of lactate, cortisol and

epinephrine. The reductions in these blood chemicals denote a state of

decreased tension and anxiety. They further observed that the reduction in

(65)

stress related chemicals persists into the post meditation period. The most

likely explanation of these results seems to be that the long term practice of

meditation develops a psycho physiological response of persistent.

Udupa et al (1975) found ample evidence showing meditation’s effects on

adreno cortical activity, specifically in the reduction of cortisol. Generally

higher levels of dehydroepiandrosterone sulfate (DHEA-S) have been reported

in TM meditators as compared to non-meditators. These studies suggest

greater health and adaptability to stress in meditators.

Jevning et al (1978) observed morning and evening norepinephrine (NE) and

epinephrine (E) following TM. Nor epinephrine, a hormone produced in the

adrenal medulla in response to direct nervous stimulation, increases blood

pressure due to vasoconstriction in the peripheral blood vessels. They

observed significantly lower levels of morning epinephrine levels were to be in

the TM group than in the control subjects.

Mills et al (1990) demonstrated that meditation reduces sympathetic

adrenergic receptor sensitivity, producing a decreased response to stressful

situations.

Glaser et al (1992) and Elias & Wilson (1995) studied increased levels of

gamma amino butyric acid (GABA), melatonin and dehydroepiandrosterone

sulfate and reported that meditation is associated with changes in the

secretion and release of several pituitary hormones.

Martarelli et al (2011) investigated the effects of diaphragmatic breathing on

exercise-induced oxidative stress and the putative role of cortisol and

melatonin hormones. They monitored sixteen athletes during an exhaustive

training session. After the exercise, athletes were divided in two equivalent

(66)

groups of eight subjects. Subjects of the studied group spent one hour

relaxing performing diaphragmatic breathing and concentrating on their

breath in a quiet place. The other eight subjects, representing the control

group, spent the same time sitting in an equivalent quite place. Results

demonstrate that relaxation induced by diaphragmatic breathing increases

the antioxidant defense status in athletes after exhaustive exercise. These

effects correlate with the concomitant decrease in cortisol and the increase in

melatonin. The consequence is a lower level of oxidative stress, which

suggests that an appropriate diaphragmatic breathing could protect athletes

from long-term adverse effects of free radicals.

Biochemical and hormonal studies provide a physiological basis to document

changes with meditation (Davidson et al. 2003, Infante et al. 1998, Elias et

al., 2000). Serotonin has a calming effect with important changes in mood,

behavior, attention and memory. Meditation increases the production of

serotonin and levels of its urinary metabolite increase significantly following

meditation (Bujatti, 1976). Melatonin is a hormone produced by the pineal

gland. It has circadian rhythm and is an important determinant for good sleep.

It is a potent antioxidant and has important role in mood changes, aging,

sexual maturation, reproduction, cancer, immune system response and many

diseases. Meditation is associated with increase in level of melatonin by 75%

to 300%. (Tooley et al 2000). Growth hormone is known to enhance stamina,

youthful energy, muscle tone and bone strength. Increase in its level with

meditation may counter effect of aging. Anxiolytic effect of meditation is

possibly related to increase in production of GABA. Cortisol is a major stress

and age accelerating hormone. There is ample evidence that levels of Cortisol

(67)

and corticotrophin levels and their response to stress reduces significantly

upto 50% following meditation. (Bevan 1980, Jevning et al 1978, Michaels et

al 1979, Jevning et al 1978, Subrahmanyam et al 1980, Sudsuang et al 1991,

Udupa et al 1975, Jevning et al 1975, Harte et al 1995).

In summary, meditation increases the production of growth hormone,

dehydroepiandrosterone (DHEA), gamma amino butyric acid (GABA),

melatonin, insulin, thyroid hormones, serotonin and dehydroepiandrosterone

and decrease in levels of cortisol, lactate, catecholamines (epinephrine and

norepinephrine etc)

EFFECT OF MEDITATION ON BRAIN

Jevning et al (1996) illustrates an interesting redistribution in the blood flow

of meditators. Blood flow to the kidneys and liver declined in practitioners,

with a surprising increase in cardiac output. These changes of blood flow

imply a marked redistribution of blood flow during meditation. It is

hypothesized that most of the distributed circulation must be to the brain, a

hypothesis that has been supported by direct estimation of increased relative

cerebral blood flow

The first published study using neuro imaging techniques to examine

meditative states used PET to measure regional cerebral metabolic rate of

glucose and found a sign of increased activity (Herzog 1990). This study did

not find a profound difference in regional or global CBF, but did find a slight

increase in frontal areas compared to visual centers in the occipital regions.

Lou (1999) used a measure of oxygen metabolism, which is more sensitive

than glucose when looking for changes in a relatively short period of time, to

(68)

compare a meditation group with a resting control group. Although mean

global CBF did not change for either of the groups, the meditation group

showed more activity in regions associated with imagery tasks.

Timmons et al (1972) compared different types of breathing during

meditation and discovered that diaphragmatic or deep breathing was

associated more with alpha response along with it they revealed that the

practice of meditation decreases muscle reflex time

Warshal et al (1980) found significant reductions in reflex time and improved

motor performance skill such as higher performance on perceptual-motor

speed tests, static motor performance tests, and physical task tests of

balance.

Raghuraj et al (1997) studied effect of breathing on hand grip strength. One

hundred thirty right hand dominant school children between 11 and 18 years

of age were randomly assigned to 5 groups. Each group had a specific yoga

practice in addition to the regular program for a 10 days yoga camp. The

practices were: (1) right (2) left (3) alternate nostril breathing (4) breath

awareness and (5) practice of mudras. Hand grip strength of both hands was

assessed initially and at the end of 10 days for all 5 groups. The right, left and

alternate-nostril breathing groups had a significant increase in grip strength of

both hands, ranging from 4.1% to 6.5%. These findings support that breathing

through a particular nostril or through alternate nostrils raise hand grip

strength of both hands without lateralization.

Naveen et al (1997) observed that uninostril breathing facilitates the

performance on spatial and verbal cognitive tasks, said to be right and left

brain functions, respectively. Since hemispheric memory functions are also

(69)

known to be lateralized, the present study assessed the effects of uninostril

breathing on the performance in verbal and spatial memory tests. School

children (N = 108 whose ages ranged from 10 to 17 years) were randomly

assigned to four groups. Each group practiced a specific yoga breathing

technique: (i) right nostril breathing, (ii) left nostril breathing, (iii) alternate

nostril breathing, or (iv) breath awareness without manipulation of nostrils.

These techniques were practiced for 10 days. Verbal and spatial memory was

assessed initially and after 10 days. An age matched control group of 27 were

similarly assessed. All four trained groups showed a significant increase in

spatial test scores at retest, but the control group showed no change. Average

increase in spatial memory scores for the trained groups was 84%. It appears

that yoga breathing increases spatial rather than verbal scores without a

lateralized effect.

Litscher et al (2001) studied the effects of Qi Gong on brain function with

modern neuromonitoring tools in two subjects and found similar effects on

both male and female subjects. When the expert meditator concentrated on

multimodal stimuli 22.2% increase in mean blood flow velocity (vm) in the

posterior cerebral artery and a simultaneous 23.1% decrease of vm in the

middle cerebral artery was seen in both of the subjects.

Davidson et al (2003) found significant increases in antibody titers to

influenza vaccine among subjects in the meditation compared with those in

the wait-list control group. The magnitude of increase in left-sided activation

predicted the magnitude of antibody titer rise to the vaccine. These findings

demonstrate that a short program in mindfulness meditation produces

demonstrable effects on brain and immune function. It may change brain and

(70)

immune function in positive ways. As significant activity in the insula area of

the brain was seen when the long-term meditators were meditating. The

insula is responsible for bodily representations of emotion. Activity also

increased in the temporal parietal junction, mainly in the right hemisphere.

This area of the brain is important in processing empathy, involved with

perceiving the mental and emotional state.

Lazar et al (2005) used MRI to compare 15 meditators, with experience

ranging from 1 to 30 years, and 15 non-meditators. In this study they

observed that certain areas of the brain were thicker in meditators than in

controls suggesting that regular practice of meditation is associated with

increased thickness in a subset of cortical regions. The changes were

predominately noticed at prefrontal cortex and the right anterior insula.

Further, it was observed that regular meditation may slow age related

thinning of the frontal cortex.

Yamamoto et al (2006) aimed to find out the source of alpha activity using

magneto encephalography (MEG) and electroencephalography (EEG)

simultaneously on TM practitioners and found the medial prefrontal cortex

(mPFC) and anterior cingulated cortex (ACC) play an important role in brain

activity induced by transcendental meditation.

Pagnoni and Cekic (2007) observed how the regular practice of meditation

may affect the normal age related decline of cerebral gray matter volume and

attention performance in healthy individuals. Voxel-based morphometry for

MRI anatomical brain images and a computerized sustained attention task

were employed in 13 regular practitioners of Zen meditation and 13 matched

controls. While control subjects displayed the expected negative correlation of

(71)

both gray matter volume and attention performance with age, meditators did

not show a significant correlation of either measure with age. The effect of

meditation on gray matter volume was most prominent in the putamen, a

structure strongly implicated in attention processing. These findings suggest

that the regular practice of meditation may have neuroprotective effects and

reduce the cognitive decline associated with normal aging.

Lutz et al (2008) presented emotional and neutral sounds during the

meditation and comparison periods. The presentation of the emotional

sounds was associated with increased pupil diameter and activation of limbic

regions (insula and cingulate cortices) during meditation (versus rest). During

meditation, activation in insula was greater while performing negative sounds

than positive or neutral sounds in expert than it was in novice meditators. The

strength of activation in insula was also associated with self-reported intensity

of the meditation for both groups. These results support the role of the limbic

circuitry in emotion sharing. The comparison between meditation vs. rest

states between experts and novices also showed increased activation in

amygdala, right temporo-parietal junction (TPJ), and right posterior superior

temporal sulcus (pSTS) in response to all sounds. This suggests greater

detection of the emotional sounds and enhanced mentation in response to

emotional human discourse for experts than novices during meditation..

Lutz et al (2009) observed that bold signal in the right middle insula shows a

significant association of brain with heart rate across state (compassion vs.

neutral) and group (novice, expert). This association was stronger in the left

middle/posterior insula when experts were compared to novices. The positive

coupling of heart rate and bold signal were higher within the compassion state

(72)

than within the neutral state in the dorsal anterior cingulate cortex for both

groups. This state effect was stronger for experts than novices in

somatosensory cortices and the right inferior parietal lobule. These findings

confirm that meditation enhances the emotional and somatosensory brain

representations of others' emotions and that this effect is modulated by

expertise.

Xiong and Doraiswamy (2009) in a cross-sectional study found meditation

practitioners to have a lower age related decline in thickness of specific

cortical regions.

Baerentsen (2010) investigated meditation with fMRI. Thirty-one individuals

with 1.5-25 years experience in meditation were scanned during the onset of

respectively meditation and normal relaxation. Additionally, 21 subjects were

scanned during 14.5 minutes of sustained meditation. During the onset of

meditation, activations were found bilaterally in the putamen and the

supplementary motor cortex, while deactivations were found predominately

in the right hemisphere, the precuneus, the posterior cingulum and the

parieto-temporal area. During sustained meditation, activation was noted in

the head of caudate nucleus. Extensive deactivations were observed in white

matter in the right hemisphere, i.e. mainly in the posterior occipito-parieto-

temporal area and in the frontal lobes. These findings provide tentative

support for the notion of frontal cortical-subcortical system dominance in the

initiation of Zen meditation.

Kaul et al (2010) showed that meditation provides at least a short term

performance improvement even in novice meditators and multiple hours

(73)

spent in meditation are associated with a significant decrease in total sleep

time.

Jun et al (2011) studied effect of meditation on insight. Forty eight university

students without meditation experience were recruited to learn a simple

meditation technique. They were given a list of 10 insight problems to solve

(the pre-test session). In this study, they focused on the unsolved problems

and examined if they could be successfully solved after a 20 min rest interval

with or without meditation. Results showed that relative to the control group

that listened to Chinese or English words and made a language judgment, the

groups who learned meditation successfully solved significantly more failed

problems from the pre-test session providing direct evidence for the role of

meditation in promoting insight. Further analysis showed that maintaining a

mindful and alert state during meditation (raising a hand to report every 10

deep breaths compared to every 100 deep breaths) resulted in more insight

regarding the failed items from the pre-test session.

Bhanoo (2011) took MRI brain scans before and after the participants’

meditation treatment and found increased gray matter in the hippocampus,

an area important for learning and memory. The images also showed a

reduction of gray matter in the amygdala, a region connected to anxiety and

stress. Control group that did not practice meditation showed no such

changes.

Sharma et al (2011) studied effect of meditation on stress-induced changes in

cognitive functions and showed the practice of meditation reduced the

physiologic stress responses without taking away the beneficial effect of stress

namely, improved memory scores. They investigated a significant increase in

(74)

physiologic (GSR, EMG, HR, QTc/QS2) and psychologic (acute stress

questionnaire scores) markers of stress. Meditation was associated with

relaxation (significant decrease in GSR, EMG, QTc/QS2, and acute stress

questionnaire scores). They revealed that if it is practiced before the stressful

event, it reduces the adverse effects of stress. Memory quotient significantly

increased whereas cortisol level decreased after stress and meditation. Hence

it was concluded that practice of meditation produces a relaxation response

even in the young adult subjects who had never practiced meditation before.

MEDITATION AND DISEASE

Deepak et al (1994) studied effect of meditation on epilepsy and found

significant reduction in seizure frequency and duration. They observed an

increase in the dominant background EEG frequency, a reduction in mean

spectral intensity of the 0.7-7.7 Hz segment, and an increment in mean

spectral intensity in the 8-12 Hz segment of the EEG. All these changes were

statistically significant. During the observation period of one year, control

patients did not show any significant changes in seizure frequency. The results

indicate that continued meditation practice is of substantial help in improving

the clinico-electrographic picture in drug-resistant epileptics.

Maclean et al. (1997) studied changes in baseline levels and acute responses

to laboratory stressors were examined for four hormones-Cortisol, growth

hormone, thyroid-stimulating hormone and testosterone-before and after 4

months of either the TM technique or a stress education control condition. At

pre- and post-test, blood was withdrawn continuously through an indwelling

catheter, and plasma or serum samples were frozen for later analysis by

(75)

radioimmunoassay. The results showed significantly different changes for the

two groups, or trends toward significance, for each hormone over the 4

months. In the TM group, but not in the controls, basal Cortisol level and

average Cortisol across the stress session decreased from pre- to post-test.

Cortisol responsiveness to stressors, however, increased in the TM group

compared to controls. The baselines and stress responsiveness for TSH and GH

changed in opposite directions for the groups, as did the testosterone

baseline. Overall, the Cortisol and testosterone results appear to support

previous data suggesting that repeated practice of the TM technique reverses

effects of chronic stress significant for health.

Panjwani et al (1996) showed effect of sahaja yoga meditation on seizure

control and electroencephalographic alterations on patients of idiopathic

epilepsy. The subjects were randomly divided into 3 groups. Group I (n = 10)

practiced sahaja yoga for 6 months, Group II (n = 10) practiced exercises

mimicking sahaja yoga for 6 months and Group III (n = 12) served as the

epileptic control group. Group I subjects reported a 62 per cent decrease in

seizure frequency at 3 months and a further decrease of 86 per cent at 6

months of intervention. Power spectral analysis of EEG showed a shift in

frequency from 0-8 Hz towards 8-20 Hz. The ratios of EEG powers in delta (D),

theta (T), alpha (A) and beta (B) bands i.e., A/D, A/D + T, A/T and A + B/D + T

were increased. Per cent D power decreased and per cent A increased. No

significant changes in any of the parameters were found in Groups II and III,

indicating that sahaja yoga practice brings about seizure reduction and EEG

changes.

(76)

Stephen (1982) studied effects of meditation-relaxation on symptoms of

anxiety and depression. 36 female volunteers (aged 63–79 years) participated

in a 20-week training programmers. Subjects were randomly assigned to 1 of 3

groups: relaxation-meditation, relaxation-meditation with a 10-week follow-

up consisting of instructions to practice on a daily basis using relaxation-

meditation tapes, and a pseudo-relaxation control group. The treatment

groups received 1 week of baseline evaluation, 10 weeks of 30-min training

sessions, and a 10-wk follow-up with taped relaxation sessions for the 2nd

group. The control group followed an identical schedule for 10 weeks but did

not participate in the follow-up. The State-Trait Anxiety Inventory and Self-

Rating Depression Scale were administered prior to treatment, at the end of

training and at the end of the follow-up period. In comparison to the control

group, the treatment groups manifested a significant pre–post treatment

decrement for both state and trait anxiety. The practice group continued to

show a decrement in state anxiety, while the no-practice group exhibited a

return toward baseline levels. However, trait anxiety continued to decrease

for both groups. When questions that correlated highly with anxiety and

somatic symptoms were removed and analyzed separately, a significant pre-

to post treatment decrement in depression was noted.

Speca et al (2000) found mindfulness meditation effective in decreasing mood

disturbance and stress symptoms in both male and female patients with a

wide variety of cancer diagnoses, stages of illness and ages. The treatment

group had fewer symptoms pertaining to cardiopulmonary systems and

gastrointestinal system, less stress, less emotional irritability, less depression,

and less cognitive disorganization.

(77)

Schneider et al (2005) found the transcendental meditation program reduced

death rates by 23%. Compared with combined controls, the transcendental

meditation group showed a 23% decrease in the primary outcome of all cause

mortality after maximum follow-up (relative risk 0.77, p = 0.039). Secondary

analyses showed a 30% decrease in the rate of cardiovascular mortality

(relative risk 0.70, p = 0.045) and a 49% decrease in the rate of mortality due

to cancer (relative risk 0.49, p = 0.16) in the meditation group compared with

combined controls. These results suggest that a specific stress-decreasing

approach used in the prevention and control of high blood pressure, can help

to decrease mortality from all causes and cardiovascular disease in older

subjects who have systemic hypertension.

Rainforth et al (2007) conducted an updated systematic review of the

published literature and identified 107 studies on stress reduction and BP.

Seventeen trials with 23 treatment comparisons and 960 participants with

elevated BP met criteria for well-designed randomized controlled trials and

were replicated within intervention categories. Meta-analysis was used to

calculate BP changes for biofeedback (−0.8/−2.0 mm Hg (P = NS); relaxation-

assisted biofeedback, (+4.3/+2.4 mm Hg (P = NS); progressive muscle

relaxation, (−1.9/−1.4 mm Hg (P =NS); stress management training, −2.3/−1.3

mm (P = NS); and the transcendental meditation program, −5.0/−2.8 mm Hg

(P = 0.002/0.02). Available evidence indicates that among stress reduction

approaches, the transcendental meditation program is associated with

significant reductions in BP, CVD risk factors and better clinical outcomes.

Oh et al (2010) observed that the medical Qigong (MQ) group significantly

improved overall quality of life (t144 = −5.761, P < 0.001), fatigue (t153 = −5.621,

(78)

P < 0.001), mood disturbance (t122 =2.346, P = 0.021) and inflammation (CRP)

(t99 = 2.042, P < 0.044) compared with usual care after controlling for baseline

variables. This study indicates that MQ can improve cancer patients’ overall

QOL and mood status and reduce specific side-effects of treatment. It may

also produce physical benefits in the long term through reduced

inflammation.

Chesia and Seretti (2010) aimed to find efficacy of mindfulness based

cognitive therapy (MBCT) on psychiatric patients and showed that it was

significantly better for reducing major depression. Their findings included: 1)

MBCT as adjunct to usual care was significantly better than usual care alone

for reducing major depression (MD) relapses in patients with 3 or more prior

depressive episodes, 2) MBCT plus gradual discontinuation of maintenance

ADs was associated to similar relapse rates at one year as compared with

continuation of maintenance antidepressants and 3) the augmentation of

MBCT could be useful for reducing residual depressive symptoms in patients

with MD and for reducing anxiety symptoms in patients with bipolar disorder

in remission and in patients with some anxiety disorders.

Manocha et al (2011) investigated the effect of meditation on work stress,

anxiety and mood in full-time workers and they found a significant

improvement for the meditation group compared to both the relaxation

control and the wait-list groups the PSQ (P = .026), and DD (P = .019). Hence

they concluded that mental silence-orientated meditation, is a safe and

effective strategy for dealing with work stress and depressive feelings. 178

adult workers participated in an 8-week, 3-arm randomized controlled trial

comparing a “mental silence” approach to meditation (n = 59) to a

(79)

“relaxation” active control (n = 56) and a wait-list control (n = 63). Participants

were assessed before and after using psychological strain questionnaire (PSQ),

a subscale of the larger occupational stress inventory (OSI), the state

component of the state/trait anxiety inventory for adults (STAI), and the

depression-dejection (DD) subscale of the profile of mood states (poms).

Salmoirago-Blotcher et al (2011) explored the characteristics of dispositional

mindfulness in unhealthy populations and evaluated its associations with

psychological morbidity and disease severity in 30 outpatients with

implantable cardioverter defibrillators who were naïve to mindfulness

training. They used the five facets of mindfulness and the hospital anxiety and

depression scale to measure dispositional mindfulness and

anxiety/depression, respectively. Associations were estimated using linear

regression models. Higher dispositional mindfulness was observed in patients

with lower anxiety scores (β = −1.10, CI = −1.71, −0.49) and no history of

depression (β = −7.95; CI = −14.31, −1.6) by univariate analysis. No

associations were observed with disease severity or other covariates. In

conclusion, psychological well-being and psychological morbidity, and not

disease severity, appear to be associated with dispositional mindfulness in

patients with implantable cardioverter defibrillators.

Lengacher et al (2011) a pilot study within-subject design was used to

investigate whether a mindfulness-based stress reduction program for cancer

(MBSR-C) improved psychological and physical symptoms, quality of life (QOL)

and stress markers among advanced-stage cancer patients and caregivers.

Patients were previously diagnosed with advanced-stage breast, colon, lung,

or prostate cancer and on treatment were recruited from the Moffitt Cancer

(80)

Center and Research Institute. Twenty-six patients and caregivers completed a

modified 6-week, self-study MBSR-C program based on the Kabat–Zinn model.

Psychological and physical symptoms and QOL were compared pre– and post–

MBSR-C sessions. Salivary cortisol and interleukin-6 were assessed pre– and

post–MBSR-C session at 1, 3, and 6 weeks. Following the 6-week MBSR

program patients showed improvements in stress and anxiety (p < .05);

caregivers’ psychological and QOL also improved but were not statistically

significant. Both patients and caregivers had decreases in cortisol at weeks 1

and 3 (p < .05) but not at Week 6. Similar to cortisol levels at week 6, salivary

interleukin-6 levels were lower overall (before/after an MBSR-C session),

compared with week 1 for patients and caregivers. It was concluded that

MBSR-C may be a beneficial intervention for reducing stress, anxiety, cortisol

levels and symptoms in advanced-stage cancer patients and may also benefit

caregivers.

Barrett et al (2012) studied effect of meditation on acute respiratory infection

(ARI). For this 154 adults randomized into the study, 149 completed the trial

(82% female, 94% white, mean age 59.3 ± 6.6 years). There were 27 ARI

episodes and 257 days of ARI illness in the meditation group (n = 51), 26

episodes and 241 illness days in the exercise group (n = 47), and 40 episodes

and 453 days in the control group (n = 51). Mean global severity was 144 for

meditation, 248 for exercise, and 358 for control. Compared with control,

global severity was significantly lower for meditation (p = .004). Both global

severity and total days of illness (duration) trended toward being lower for the

exercise group (p=.16 and p=.032, respectively), as did illness duration for the

meditation group (p=.034). Viruses were identified in 54% of samples from

(81)

meditation, 42% from exercise and 54% from control groups. Neutrophil count

and interleukin-8 levels were similar among intervention groups. The study

shows that training in meditation or exercise can be effective in reducing ARI

illness burden.

Matchim (2012) examined the effects of a MBSR program on physiological

and psychological outcomes among early-stage breast cancer survivors. A

quasi-experimental, pre-and posttest control group design was selected. The

intervention group received the MBSR intervention. The control group

received no MBSR intervention. The intervention group demonstrated

statistically significant improvement in physiological and psychological

outcomes including reduced blood pressure, heart rate, and respiratory rate

and increased mindfulness state at the level of p = .05 to p = .001. The effects

of MBSR on reducing stress in this sample were statistically significant on the

physiological outcome (morning cortisol) at the measurement after the

intervention completion but this effect was not sustained at 1-month follow-

up. MBSR showed a trend toward improving psychological outcomes by

reducing mood disturbance in this sample.

MEDITATION AND EEG WAVES

Changes in EEG with meditation have been described for last 50 years but well

controlled scientific studies are still lacking. Here we describe important

studies related to different meditation techniques.

Zen meditation and EEG

Kasamatsmu (1957) recorded electroencephalograms on two expert

practitioners of "Zen" and "Yoga" during their performances and were

(82)

compared with those of two control subjects, The control subjects, whose

resting EEGs were similar to those of practitioners, were selected. With

progress of "Zen" and "Yoga" performances, alpha waves of practitioner's EEG

increased remarkably, even if their eyes were kept open .The above

phenomena had a clear contrast to the poor alpha waves of the controls in the

same stage. The alpha waves during "Zen" or "Yoga" performance were hardly

depressed by the sounds of hand claps or bells.

Kasamatsmu and Hiraim (1966) studied brain wave activity of 16 Zen priests

and 32 of their disciples were recorded during a period of Sesshin at a

traditional Zen Buddhist training hall. While meditating, novice disciples with 1

to 5 years of Zazen training were found to produce a steady pattern of alpha

waves, even with their eyes open. More intermediate disciples with 5 to 20

years of training had a tendency to exhibit a slowing of their brain waves, as

indicated by drops in alpha wave frequency. They found that in the beginning

of meditation, alpha waves appeared strongly but after sometimes the theta

waves appeared as Zen meditation progressed. These changes were clearly

shown in EEG of another Zen master of 60 years of age who showed large

alpha waves in 8-9/sec frequency after 24 minutes of his Zen meditation. And

30 seconds later, the rhythmical theta train (6-7/sec. 60-70pV.) begins to

appear. Some subjects only showed the appearance of alpha waves through

the all meditation period and others showed the typical series of

electrographic changes. The author classified the changes of

electroencephalogram during Zen meditation in the following four stages:

i. A slight change which is characterized by the appearance of alpha

waves in spite of opened eyes.

(83)

ii. The increase in amplitude of persistent alpha waves.

iii. The decrease of alpha frequency.

iv. The appearance of the rhythmical theta train, which is the final change

of EEG during Zen meditation but does not always occur.

Tomio Hirai (1989) studied the practice of Zazen by seasoned priest

practitioners and controls using EEG and various physiological measures. He

found that there were four distinct phases in the meditation of the

experienced priests:

Stage I—appearance of alpha waves,

Stage II—increasing alpha amplitude,

Stage III—decreasing alpha frequency, and

Stage IV—appearance of rhythmical theta trains.

He introduced various sounds, clicks and names, to see what happened to the

brain waves of the meditators and controls. While both the experienced

meditators and the controls initially reacted to these stimuli by blocking the

then dominant rhythm, the meditators' blocking time was a matter of a few

seconds and the controls much longer. However, whereas the controls

habituated to the sounds very quickly, the experienced meditators did not.

This indicated that the controls got caught up by the stimuli with associations,

but eventually ignored the stimuli, whereas the experienced meditation

quickly let go of whatever associations that may have occurred to them and

remained open to new stimuli.

Kubota (2001) studied simultaneous EEG and ECG recordings in persons

practicing Zen meditation which required sustained attention and breath

(84)

control. They specifically looked into frontal midline theta rhythm (Fm theta)

which reflects mental concentration as well as meditative state or relief from

anxiety. For the subjects in which Fm theta activities were provoked (six men,

six women, 48% of the total subjects), peripheral autonomic activities were

evaluated during the appearance of Fm theta as well as during control

periods. Successive inter-beat intervals were measured from the ECG to assess

cardiac sympathetic and parasympathetic functions separately. Both

sympathetic and parasympathetic indices were increased during the

appearance of Fm theta compared with control periods. Theta band activities

in the frontal area were correlated negatively with sympathetic activation. The

results suggest a close relationship between cardiac autonomic function and

activity of medial frontal neural circuitry.

Murata et al (2004) compared 20 monks (10 with extensive experience, 10

with moderate experience) to 10 controls prior to and during Zen meditation

and found that slow alpha appeared in all the groups but that theta activity

only appeared in the experienced group affecting the frontal region, with the

likelihood of it occurring increasing proportionally to the level of experience.

They further investigated the relationship between trait anxiety levels,

relaxation response and internalized attention (alpha synchronization) during

a Zen meditation technique known as ‘susoku’ using 22 novice meditators.

Their findings showed increased frontal alpha (slow) coherence (frontal to

central), with lower levels of trait anxiety correlating with internalized

attention meditation, whereas higher trait anxiety induced meditation

characterized predominantly by a relaxation response.

(85)

Takahashi et al (2005) monitored EEG, ECG (to measure heart rate variability)

and respiratory rate in 20 novice meditators and found increased theta and

slow alpha wave activity in frontal areas and decreased sympathetic and

increased parasympathetic activity during meditation. The authors point out

that alpha and theta waves are independently involved in behaviors of the

mind during meditation and suggest that successful meditation involves

slower frontal alpha synchronization coupled with reduced sympathetic

activity and that mindfulness may activate fast theta activity in the frontal

areas as well as increased parasympathetic activity.

Chang and Lo (2005) studied EEG changes in Zen meditators at various levels

of experience who meditated over a 40 minute period. They distinguished five

different meditation states: delta, delta plus theta, theta plus slow alpha, high

amplitude alpha, and an amplitude suppressed wave state. Five different

"meditation scenarios" were observed in the meditators studied.

Persistent alpha activity dominates the entire meditation session. The

meditators reported flights of thought throughout the meditation session with

abrupt shifts to peaceful states accompanied by feelings of light.

Four EEG patterns--alpha, delta, theta and amplitude suppressed wave state

rotationally. Meditators reported switches among sensations of interference

of mental activities, alertness and tenseness, subliminal consciousness and

feelings of sacred, peaceful light. Their conclusions were :

i. EEG signals of background amplitude suppressed wave state

predominate with very few alpha activities and scattered delta. This

occurred with very experienced meditators.

(86)

ii. Background amplitude suppressed wave state was sprinkled with alpha

rather than delta. The meditators reported a bright light and feelings of

being fully relaxed during the session.

iii. The amplitude suppressed wave state dominates from the beginning of

meditation and no other activity is observed to be significant.

Liu and Lo (2006) investigated the spatial distribution of alpha power during

meditation. They studied Zen meditation practitioners (the experimental

group) and compared them with non-practitioners (the control group). They

found that (1) the alpha power in the control group decreased dramatically

but not in the experimental group, (2) after meditation alpha power in the

frontal area of meditators increased more than that of the control subjects

(after resting-EEG recording). They speculated that activating the medial

prefrontal cortex and the anterior cingulate cortex during meditation may be

the reason for increasing frontal alpha power.

Electroencephalogram investigations of Zen meditation consistently showed

increased alpha and theta power, increased alpha coherence and overall

frequency slowing, and the less consistent finding of gamma band effects.

Increased alpha power is generally observed in frontal regions. There are

mixed findings relating to alpha blocking and habituation. However, theta

activity was shown to have a close positive association with the level of

practice. Neuroimaging research of Zen meditation has shown increased

activation of the frontal cortical-subcortical system, including prefrontal

cortex, basal ganglia and reduced activation across a number of other brain

regions. Four Zen EEG changes :

1. Control subjects show no alpha increases.

(87)

2. Beginner Zen subjects show increased alpha amplitude mainly at the

back of the head (occipitals).

3. Intermediate Zen subjects show increased alpha amplitudes which

spread forward on the head and which slow in frequency.

4. Advanced Zen subjects show the above changes, but in addition also

show rhythmic trains of theta EEG, which are morphologically different

from the theta of drowsiness. The theta wave criterion is a stringent

one for alpha feedback, since only advanced Zen with 21-40 years

showed it.

Transcendental meditation and EEG

Banquet (1973) studied effect of transcendental meditation on subjects (9

males, 3 females) and a group of twelve matched controls. Three of the

controls (2 males and 1 female) were also experimental subjects and were

tested before and after starting meditation. The results were derived from the

comparative interpretation of the conventional EEG and frequency spectrum

arrays, for both control and experimental subjects. They concluded that :

1. Alpha rhythm increased in amplitude, slowed down in frequency and

extended to anterior channels at the beginning of mediation.

2. In second stage, theta frequencies different from those of sleep

diffused from frontal to posterior channels. They took the form of short

theta periods or longer rhythmic theta trains.

3. Rhythmic amplitude-modulated beta waves were present over the

whole scalp in a third stage of deep meditation by advanced subjects.

(88)

4. The most striking topographical alteration was the synchronization of

anterior and posterior channels.

They further concluded that EEG records from meditators practicing TM

distinguish the meditative state from other states of consciousness. The

combination of sequential EEG changes in relation to topographical alterations

produces a particular pattern.

Hebert and Lehmann (1977) surveyed the EEG characteristics of persons

practicing the transcendental meditation technique. Twenty one of seventy

eight people demonstrated irregular prominent bursts of frontally dominant

theta activity. On the average across subjects, the theta bursts occurred about

every 2 minutes had an average duration of 1.8 second and average maximal

amplitude of 135 µV. typically the bursts were preceded and followed by

alpha rhythm. Subjective impressions elicited that during theta bursts was

associated with pleasant states with intact situational orientation and not s

related to sleep. In contrast fifty four non meditating controls showed no

theta bursts during relaxation and sleep onset. They hypothesized that theta

burst may be the manifestation of a state adjustment mechanism which

comes into play during prolonged low-arousal states, and which may be

related to EEG patterns of relaxation in certain behavioural conditions

Travis (2001) compared autonomic and EEG variables during 10-min, order-

balanced eyes-closed rest and Transcendental Meditation (TM). TM sessions

were distinguished by (1) significantly lower breath rates, (2) lower skin

conductance levels, (3) higher respiratory sinus arrhythmia amplitudes and (4)

higher alpha anterior–posterior and frontal EEG coherence. Alpha power was

not significantly different between conditions. These results were seen in the

(89)

first minute and were maintained throughout the 10-min sessions. These

findings suggest that monitoring patterns of physiological variables may index

dynamically changing inner experiences during meditation practice.

Travis et al (2010) brain wave differences between students practicing the

Transcendental Meditation (TM) and those simply resting with their eyes

closed. They concluded below:

1. TM produces alpha-1 (7-9 Hz) EEG mainly in frontal areas. This brain

wave activity is characteristic of reduced mental activity and physical

relaxation occurring simultaneously while remaining alert.

2. TM produces a unique state of "restful alertness," as seen in the

markedly higher alpha power in the frontal cortex and lower beta and

gamma waves in the same frontal areas during TM practice.

3. Creates greater alpha coherence between the left and right

hemispheres of the brain suggesting the brain is working as a whole.

Various EEG studies indicate that when sit quietly with eyes closed and focus

on mantra, many TM meditators show a steady pattern of alpha waves. A

small number of them may show a drop in wave frequency to the lower part

of the alpha spectrum (8 to 9 Hz) followed by the brief appearance of a theta

wave pattern (Banquet 1973, Cahn and Polich 2006, Davidson 1976,

Ferguson 1975, Jevning et al 1992, Stigsby et al 1981, Wallace 1970, West

1980, Woolfolk 1975). These patterns are often recorded from electrode sites

located over the frontal lobes and near the brain’s midline (Wallace et al.

1971). This suggests that, as they meditate, the brain waves of TM

practitioners tend to gradually slow down and approach frequencies that are

typically associated with low mental arousal, which would be consistent with a

(90)

calming effect. In addition, some TM practitioners may show patterns of

synchronized brain waves, a phenomenon often known as EEG coherence

(Ferguson 1975, Jevning et al 1992, West 1980).

Qigong and EEG

Pan et al (1994) studied the differences in EEG theta waves between

concentrative and non-concentrative Qigong states by means of power

spectrum analysis and EEG mapping. The adult subjects included 20

practitioners of concentrative Qigong, 30 practitioners of non-concentrative

Qigong and 23 control subjects. The results showed that frontal mid-line theta

rhythm was related to concentrative Qigong state. As the theta rhythm has

been suggested to be one of the normal EEG patterns occurring in mental

concentration, it is concluded that the theta rhythm is an indicator of mental

concentration.

Qin (2009) did a follow-up EEG study was conducted on a subject with 50

years of experiences in Qigong. Resting EEG at present showed frontally

dominant alpha-1 as compared to occipitally dominant alpha-2 described in

1962. During the Qigong practice alpha-1 enhanced quickly and became

far more prominent than 50 years ago. Compared with baseline, these

activities remained to be higher at rest after the Qigong practice. These

findings suggest that extended practice in meditation may change the EEG

pattern and its underlying neurophysiology. It remains to be explored as to

what biological significance and clinical relevance do these physiological

changes might mean.

(91)

Sahaja Yoga and EEG

Aftanas and Golosheykin (2002) used non-linear analysis to investigate the

dynamical properties underlying the EEG in the model of Sahaja Yoga

meditation. They investigated 20 experienced meditators during rest and

meditation using 62-channel EEG. When compared to rest, the meditation was

accompanied by a focused decrease of DCx estimates over midline frontal and

central regions. By contrast, additionally computed linear measures exhibited

the opposite direction of changes: power in the theta-1 (4-6 Hz), theta-2 (6-8

Hz) and alpha-1 (8-10 Hz) frequency bands was increased over these regions.

The DCx estimates negatively correlated with theta-2 and alpha-1 and

positively with beta-3 (22-30 Hz) band power.. Overall, the results point to the

idea that dynamically changing inner experience during meditation is better

indexed by a combination of non-linear and linear EEG variables.

Aftanas and Golosheykin (2005) studied EEG activity in long-term meditators

under conditions of non-emotional arousal (eyes-closed and eyes-open

periods, viewing emotionally neutral movie clip) and while experiencing

experimentally induced negative emotions (viewing aversive movie clip). The

62-channel EEG was recorded in age-matched control individuals (n=25) and

Sahaja Yoga Meditators (SYM, n=25). Findings from the non-emotional range

show that at the lowest level of arousal (eyes closed) SYM manifested larger

power values in theta-1 (4-6 Hz), theta-2 (6-8 Hz) and alpha-1 (8-10 Hz)

frequency bands. During eyes-closed and eyes-open periods the controls were

marked by larger right than left hemisphere power, indexing relatively more

active left hemisphere parieto-temporal cortex whereas meditators

manifested no hemisphere asymmetry. When contrasted with the neutral, the

(92)

aversive movie clip yielded significant alpha desynchronization in both groups,

reflecting arousing nature of emotional induction. In the control group along

with alpha desynchronization emotional movie clip synchronized gamma

power over anterior cortical sites. This was not seen in the SYM. Overall, the

presented report emphasizes that the revealed changes in the electrical brain

activity associated with regular meditation practice are dynamical by nature

and depend on arousal level. The EEG power findings also provide the first

empirical proof of a theoretical assumption that meditators have better

capabilities to moderate intensity of emotional arousal and this can be

summarized as below:

1. Meditation resulted in increase power values in theta and alpha

frequency bands.

2. Changes EEG waves with emotion and arousal are less in meditators

then in control group. It suggests that changes in meditators are more

permanent and not effected by environment.

Baijal and Srinivasan (2010) investigated the temporal dynamics of oscillatory

changes during Sahaj Samadhi meditation. EEG was recorded during

Sudarshan Kriya yoga meditation for meditators and relaxation for controls.

Spectral and coherence analysis was performed for the whole duration as well

as specific blocks extracted from the initial, middle and end portions of Sahaj

Samadhi meditation or relaxation. The generation of distinct meditative states

of consciousness was marked by changes in spectral powers especially

enhanced theta band activity during deep meditation in the frontal areas.

Interestingly, increased frontal theta activity was accompanied reduced

activity (deactivation) in parietal–occipital areas signifying reduction in

(93)

processing associated with self, space and, time. Meditators also exhibited

increased theta coherence compared to controls. The emergence of the slow

frequency waves in the attention-related frontal regions provides strong

support to the existing claims of frontal theta in producing meditative states

along with quality effects in attention processing. Interestingly, increased

frontal theta activity was accompanied reduced activity in parietal-occipital

areas.

Acem Meditation and EEG

Lagopoulos (2009) examined EEG changes during nondirective meditation.

The investigational paradigm involved 20 minutes of acem meditation, where

the subjects were asked to close their eyes and adopt their normal meditation

technique, as well as a separate 20-minute quiet rest condition where the

subjects were asked to close their eyes and sit quietly in a state of rest. Both

conditions were completed in the same experimental session with a 15-

minute break in between. They found significantly increased theta power for

the meditation condition when averaged across all brain regions. On closer

examination, it was found that theta was significantly greater in the frontal

and temporal–central regions as compared to the posterior region. There was

also a significant increase in alpha power in the meditation condition

compared to the rest condition, when averaged across all brain regions, and it

was found that alpha was significantly greater in the posterior region as

compared to the frontal region. Findings from this study suggest that

nondirective meditation techniques alter theta and alpha EEG patterns

significantly more than regular relaxation. The greater theta in frontal and

temporal-central regions than in posterior regions was thought to reflect

(94)

neural processing in the frontal midline (anterior cingulate cortex) and limbic

areas, which have a prominent role in emotional processing (relaxed attention

with theta). The abundance of posterior alpha waves was thought to be

related to reduce cognitive processing in sensory-related areas (silent

experiences with alpha).

Vipasana Meditation and EEG

As a way to compare mindfulness with concentration meditation, psychologist

Bruce Dunn and his associates at the University of West Florida had taught a

group of 10 college students how to meditate using a concentrative technique

(focusing on their breaths, similar to TM) and a mindfulness technique that

closely resembles Vipasana (Dunn et al. 1999). After a little over a month of

practice with each technique, the students were asked to meditate using each

technique while their EEGs were recorded. Compared to concentrative

meditation, the Vipasana like mindfulness meditation was associated with

more brain wave activity in the delta, theta, alpha, and beta frequencies. The

theta activity was localized primarily to the frontal lobes, while the delta,

alpha, and beta activity was spread out more across the frontal, temporal, and

parietal lobes. Curiously, many of these wave patterns appeared

simultaneously in their respective brain regions. Investigators suggested that

this may be consistent with the idea of meditation of being a state of "relaxed

awareness": slow brain waves (e.g., theta) appearing in the front of the brain

may contribute to the meditator’s calming of their mind, while faster brain

waves (e.g., alpha, beta) occurring in the back of the brain may at the same

time keep the meditator alert and aware of their surroundings.

(95)

Cahn et el (2010) observed decrease in frontal delta power, especially in those

participants not reporting drowsiness during meditation and relative increase

in frontal theta power during meditation. Greater frontal theta activity in

mindfulness meditation has presumed association with resting relaxation and

focused concentration. In addition, there was significantly increased parieto-

occipital gamma (35–45 Hz) power, but no changes were observed for the

theta (4–8 Hz), alpha (8–12 Hz), or beta (12–25 Hz) bands. Cross-experimental

session occipital gamma power was the greatest in meditators with a daily

practice of 10+ years, and the meditation-related gamma power increase was

similarly the strongest in such advanced practitioners. The findings suggest

that long-term Vipasana meditation contributes to increased occipital gamma

power related to long-term meditational expertise and enhanced sensory

awareness.

Chiesa (2010) observed a significant increase in alpha and theta activity during

meditation. Neuroimaging studies showed that meditative practice activates

the prefrontal cortex (PFC) and the anterior cingulate cortex (ACC) and that

long-term meditation practice is associated with an enhancement of cerebral

areas related to attention.

MISCELLANEOUS

Bagchi and Wenger (1957) studied traditional Indian Yogis using a portable

transistor polygraph to measure changes in the autonomic nervous system.

Compared to a group of yoga students, the Yogis showed faster heart rates,

higher blood pressure and skin conductance in their palms and lower finger

temperatures while meditating. Their breaths were also noted to become very

(96)

slow and shallow, to the point where they would sometimes not be countable.

The EEG recordings tended to show a steady alpha wave pattern throughout

the meditation period with little sign of any other change.

Niedermeyer (1997) studied brain physiology during meditation had most

frequently employed the electroencephalograph (EEG) for the measurement

of brain wave electrical activity. With most meditative practices the EEG

patterns exhibit a slowing and synchronization of brain waves, with alpha

waves predominating. More advanced practitioners of meditation

demonstrate an even greater slowing of their brain waves with the possible

emergence of theta wave patterns.

Oliveros et al (1994) recorded EEG in 11 patients graded by Silva’s method

under basal conditions and under dynamic meditation. They reported

significant increase in the mean values of alpha potency in occipital (O1, O2)

and temporal (T3, T4) region while practising dynamic meditation.

Lee et al (1997) investigated the effects of ChunDoSunBup (CDSB) Qi-training,

one of the Korean popular Qi-training systems, on EEG patterns. CDSB Qi-

training procedure consists of 3 stages: sound exercise, reciting Chunmoon

which is similar to a mantra; haeng-gong, a kind of body motion; and

mediation. Compared to the control state (resting state before Qi-training),

subjects reported less state anxiety, their activation coefficients decreased

significantly in the occipital regions. Mean relative power and changes of

mean absolute power of alpha wave increased significantly in the occipital

regions. These results suggest that sound exercise and meditation reduce

activation of the visual cortex and influence the thalamus and other functions

(97)

of the brain. These could reduce anxiety levels and modulate the

psychological, neurological and physiological functions in man.

Mason et al (1997) found the experimental group to have theta-alpha activity

simultaneously with delta activity and decreased chin electromyograph (EMG)

during deep sleep (p = 0.002) compared to short-term practitioners. Spectral

analysis fast Fourier transform (FFT) data of the first three cycles showed that

the experimental subjects had significantly greater theta 2 (6-8 Hz)-alpha 1 (8-

10 Hz) relative power during stages 3 and 4 than the combined control groups

[t(30) = 5.5, p = 0.0000008] with no difference in time in delta. There was a

graded difference across groups during stages 3 and 4 in theta 2-alpha 1

power with experimental having greater power than short-term practitioners,

who in turn had greater power than non-practitioners [t(30) = 5.08, p =

0.00002]; and 5) experimental also had increased rapid eye movement (REM)

density during REM periods compared to short-term practitioners (p = 0.04).

Inanaga (1998) studied the correlation of mental activity and theta rhythm at

the midline of the frontal area in normal subjects during mental task

performance, rest and sleep. Frontal midline theta rhythm (Fm theta) is a train

of rhythmic waves at the frequency of 6- Hz and can be induced by various

mental tasks. Fm theta is provoked not only during mental tasks but also

during nocturnal sleep in which it was most frequent during rapid eye

movement (REM). It was second most frequent during stage 1 of non-REM

(NREM) sleep and the relationship of Fm theta to dream images was also

found. Therefore it is concluded that the appearance of Fm theta is related to

mental activity even during sleep.

(98)

Klimesch (1999) presented EEG oscillations of alpha and theta band and

explored good performance is related to two types of EEG phenomena (i) a

tonic increase in alpha but a decrease in theta power, and (ii) a large phasic

(event-related) decrease in alpha but increase in theta, depending on the type

of memory demands.

Khare and Nigam (2000) carried a study on 30 normal healthy individuals and

found prominence of alpha wave activity and increment in its voltage

compared to control group. Percentage of alpha waves was also higher in

persons performing meditation. Alpha rhythm was significantly more and with

good coherence in meditators which was showing good homogeneity,

uniformity and increased orderliness of the practitioners’ brain.

Kamei et al (2001) studied changes in brain waves and blood levels of serum

cortisol during yoga exercises given by seven instructors. This study revealed

that exercises increased alpha waves and decreased serum cortisol in exercise

practitioner.

Arambula et al (2001) found development of alpha with shift in breathing.

Visual analyses of the data showed a decrease in respiration rate during the

meditation from a mean of 11 breaths/min for the pre- and 13 breaths/min

for the post baseline to a mean of 5 breaths/min during the meditation with a

predominance of abdominal/diaphragmatic breathing. There was also more

alpha EEG activity during the meditation (M = 1.71 mV) compared to the pre-

(M = .47 mV) and post baseline (M = .78 mV) periods. An increase in theta EEG

activity was observed immediately following the meditation (M = .62 mV)

compared to the pre-baseline and meditative periods (each with M = .26 mV).

(99)

These findings suggest that a shift in breathing patterns may contribute to the

development of alpha EEG.

Jacobs and Friedman (2004) studied effects of relaxation techniques on

central nervous system using spectral analysis of EEG activity. Thirty-six

subjects were randomized to either relaxation technique or a music

comparison condition. After listening to relaxation technique audio tape or

music audiotapes daily for 6 weeks, the acute central nervous system effects

of relaxation technique and music were measured using power spectral

analysis of alpha and theta EEG activity in all cortical regions. Relaxation

technique produced significantly greater increases in theta activity in multiple

cortical regions compared to the music condition. These findings are

consistent with widespread reductions in cortical arousal during relaxation

technique. They extend previous findings and suggest that theta, and not

alpha, EEG may be the most reliable marker of the central nervous system

effects of relaxation technique. These findings demonstrate that relaxation

technique produces greater reductions in central nervous system activity than

a credible comparison condition. The findings suggest that relaxation

technique represent a hypoactive central nervous system state that may be

similar to Stage 1 sleep and that it may exert their therapeutic effects in part

through cerebral energy conservation/restoration.

Beauregard and Paquettea (2008) studied EEG pectral power and coherence

in 14 Carmelite nuns during a mystical experience. These experiences, which

are characterized by a sense of union with God, are commonly reported

across all cultures. EEG activity was recorded during a control condition and a

mystical condition. In the mystical condition compared to control condition,

(100)

there was greater theta power at frontal, central and parietal regions of brain

and greater gamma1 power temporal and parietal regions. In addition, there

was greater coherence for theta and alpha bands.

Vialatte (2009) observed paroxysmal gamma waves (PGW) in eight subjects

practicing a yoga technique of breathing control called Bhramari Pranayama

(BhPr).

Ganpat et al (2011) aimed to measure the effect of self management of

excessive tension (SMET), a yoga based stress management program on brain

wave coherence. Brain wave recordings were taken with Brain Master 2

Channel EEG (version-2.0). The subjects for the study were 72 corporate

executives, 48.75±3.86 years of mean age. EEG data was recorded on the first

and sixth day of 5 days SMET program. A complete statistical and spectral

analysis showed 19.31% increase (p=0.03) in delta, 5.04% increase (p=0.65) in

theta, 15.40% increase (p=0.09) in alpha, 1.67% decrease (p=0.54) in beta and

18.68% increase (p=0.07) in gamma wave coherence between pre and post

intervention measurements. These results suggest that participation in a

SMET program was associated with improvement in emotional stability and

may have implications for ‘Executive Efficiency’.

Abdullah and Omar (2011) studied the effect of religious activities to the

human brain. EEG signals from subject at rests, as well as in different cognitive

states; listening to Quran recitation and listening to hard music were

measured and analysed. Their analysis showed that listening to Quran

recitation can generate alpha wave and can help a person always in relax

condition compared with listening to hard rock music.

(101)

Vijayalakshmi et al (2011) analyzed the variation in mean and standard

deviation of alpha and theta waves and found that the mean value of alpha

wave for thirteen subjects showed an increase whereas two subjects showed

a decrease after meditation. The amplitude of theta parameters for 14

subjects showed an increase while one subject showed a decrease. The

amplitude of delta shows an increase of 73.34% and a decrease of 26.67%.

Thus increase in the alpha and theta parameters showed the suggestive of

relaxation after meditation.

Doufesh (2012) investigated the proposition of relaxation offered by

performing the Muslim prayers by measuring the alpha brain activity in the

frontal (F3–F4), central (C3–C4), parietal (P3–P4), and occipital (O1–O2)

electrode placements using the International 10–20 System. Nine Muslim

subjects were asked to perform the four required cycles of movements of

Dhuha prayer, and the EEG were subsequently recorded with open eyes under

three conditions, namely, resting, performing four cycles of prayer while

reciting the specific verses and supplications, and performing four cycles of

acted salat condition (prayer movements without any recitations). Analysis of

variance (ANOVA) tests revealed that there were no significant difference in

the mean alpha relative power (RPα) between the alpha amplitude in the

Dhuha prayer and the acted conditions in all eight electrode positions.

However, the mean RPα showed higher alpha amplitude during the

prostration position of the Dhuha prayer and acted condition at the parietal

and occipital regions in comparison to the resting condition. Findings were

similar to other studies documenting increased alpha amplitude in parietal

and occipital regions during meditation and mental concentration. The

(102)

incidence of increased alpha amplitude suggested parasympathetic activation,

thus indicating a state of relaxation.

STUDIES ON PREKSHA MEDITATION ON DIFFERENT FIELDS

Gaur and Betal (1999) studied effect of Preksha Meditation on drug abusers’

personality. They undertook 60 male students with the age ranging from 14-

16 years, having similar socio-economic status. The all students were divided

into two groups experimental and control. The experimental group was

applied with two months practice of Preksha Meditation. They observed that

besides this improvement in psychological health the subjects also reduced

the tendency of drug taking.

Gaur and Saini (2002) observed reduction in anxiety and hassles of prisoners

who performed Preksha Meditation. They revealed that the prisoners reduced

their anxiety significantly (p < .001) and also reduced their hassles, in six areas,

viz. health (p < .001), family (p < .001), society (p<.001) occupation (p < .05),

economy ( p < .05) and others ( p<.001).

Mishra and Gupta (2006) observed that Preksha Meditation is helpful in

controlling and managing diabetes. In this study 50 male subjects suffering

from diabetes mellitus type 2 in the age of 50-70 were selected on random

basis and they were divided into two groups each of 25. They found significant

reduction in the mean values of fasting blood sugar level in experimental

groups at all points of observation i.e. 2 months, 4 months, 12 months. The

difference between the total cholesterol level of both the groups was also

statistically significant (p <0.01 and p < 0.001). In case of triglyceride, the

control group of subjects was found to being almost at constant level during

(103)

the follow up period. In contrast, there was a regular decline in the

triglyceride in experimental group of subjects at all follow-up periods.

Gaur & Jain (2006) studied effect of Preksha Meditation on stress, adjustment

and frustration of professional college married women students and found

significant improvement in all the area. They undertook 120 subjects and

divided them into three groups i.e. experimental group, control group I and

control group II each of 40 students, all the subjects were between the age of

22-28 years. They observed mean of stress level of the experimental group

showed significant decrease (p < 0.0005) in their stress level where as the

subjects of control group showed no change in their stress level. They also

found statistically significant improvement in adjustment skill and reduction in

frustration emotion after applied Preksha Meditation.

Gaur and Shah (2007) studied effect of Preksha Meditation on delinquent

behavior and brain and autonomic functions of juvenile delinquents. They

studied 60 juvenile delinquents from Chamber Children’s Home, Mumbai and

divided into two groups, each of thirty subjects. All the subjects were male in

the age group 14-18 years. Thirty juveniles who were selected as experimental

group were applied Preksha Meditation for sixty minutes per day, for two

months for phase I and another two months for phase II. They found the EEG

activity in the occipital areas (p<.0005) and frontal (p<.0005) slowed down

significantly in subjects of the experimental group as compared to subjects of

the control group and on ANS functions on both of the heart rate and

respiration rate showed significant slowing down in the group practicing

Preksha Meditation compared to the normal activity performing group.

(104)

Gaur and Prajna (2007) studied influence of Preksha Meditation on

personality and eight states of emotion, viz. anxiety, stress, depression,

regression, fatigue, guilt, extra – version, and arousal. In this research, sample

of 120 undergraduate girls were undertaken. The total subjects were divided

into two groups, experimental and control each of sixty students.

Experimental group practiced half an hour daily in morning for three months.

Significant decrement was observed in anxiety (p < .0005), stress (p < .0005),

depression (p < .005) and guilt (p < .005). Meditators are found to be better in

their extroversion and arousal capacity (p < .0005 &p < .0005) than those of

control group. The three months practice of PM brought out significant

changes in all eight areas of emotion.

Prajna and Shah (2008) studied role of Preksha Meditation and yoga in allergy

and asthma. 100 patients with various allergic disorders were included in this

study. They were grouped according to age i.e. 15-30 years, 30-45 years and

above 45 years. They were further divided into two groups based on whether

they were given practice of Preksha Meditation or not. Prajna and Shah noted

immediate improvement after 1-2 months of immune therapy in case of

allergic rhinitis and conjunctivitis patients practicing meditation. In contrast, in

group 2 (without yoga) improvement was seen only after 4-5 months with

immune therapy alone.

Gaur B.P. and Sharma (2008) studied effect of Preksha Meditation on mental

health, reactions to frustration and personality variables of prisoners. In this

investigation 100 prisoners were selected from the central jail Jodhpur

(Rajasthan). They all were undergoing life imprisonment for committing

murder. The average age of the prisoners was 25-30 years. The all prisoners

(105)

were divided into two groups i.e. experimental and control group, each of 50

prisoners. Investigator of this study found significant difference on all the 11

factors of prisoners mental health, viz. anxiety (p<.0005) despair (p<.0005),

anger (p<.0005), headache (p<.0005), fatigue (p<.0005), sleeplessness

(p<.0005), constipation (p<.0005) and acidity (p<.0005). Moreover they found

experimental group to be more relax, restful, enthusiastic, hopeful, calm,

fresh, and active having better sleep and appetite. They showed improvement

in their somatic and psychological health. Increment of their total health was

statistically significant (p < .0005).

Pragya and Bafna (2009) studied effect of Preksha Meditation in adolescent

and childhood asthma and found positive results on experimental group. A

sample of 8o adolescent children patients was included in this study, out of

148 asthmatics adolescents. They were divided into two groups, 40 each, yoga

and meditation (y) and control (c). The subjects were within the range of 13-

18 year. The subjects who had the following attributes were included in the

study: (1) patients who satisfied the diagnostic criteria of ATS (American

thoracic society guideline, 2007), (2) patients with bronchial asthma of

minimum 2 years duration, and (3) seasonal or perennial asthma.

Mishra and Sharma (2009) studied effect of swas Preksha on cardiac and

respiratory variables. They undertook 60 students in the age group of 18-25

years and divided them into two groups i.e. experimental and control. They

observed that Swas Preksha causes inhibition of sympathetic nervous system

and activation of parasympathetic nervous system, which ultimately

decreases the metabolic rate. After six months practice of Swas Preksha, there

(106)

was significant reduction in body weight, reduction in heart rate and

reduction in both systolic and diastolic blood pressure.

Mishra and Shekhawat (2009) studied efficacy of Preksha Meditation on

cardiovascular functions and blood profile of adults and found the following

results:

A significant decline in blood pressure (systolic, diastolic and mean

pressures) was observed in the subjects of experimental group both

after three and six months practice of Preksha Meditation.

Quantitative serum total cholesterol, triglyceride, low density

lipoprotein and very low density lipoprotein of the subjects of

experimental group were found to be reduced up to significant level

after six months practice of Preksha Meditation, whereas the mean

value of serum high density lipoprotein increased significantly.

The quantitative blood glucose in subjects of experimental group

decreases significantly after practice of Preksha Meditation.

A significant increase in red blood cells count was also noticed in

experimental group of subjects following the experimental

intervention.

The practice of Preksha Meditation intervention has yielded a

significant decline in the erythrocyte sedimentation rate in

experimental group.

The six month Preksha Meditation intervention has also resulted in

significantly enhanced hemoglobin level in experimental group.

(107)

Gaur B.P. and Bhardawaj (2010) studied effect of Preksha Meditation on

stress, inferiority and insecurity feeling in adolescents. They undertook 160

students, who were divided into two groups each of eighty students. All the

subjects were male with age ranging from 15- 18 (an average age of 16.5

years) years. The subjects of experimental group practiced Preksha Meditation

regularly for forty minutes daily for a period of six months and found the

following results:

Levels of all the five areas of stress (achievement stress, physical stress,

institutional stress, academic stress, family stress) increased in the

control group and the group performing P.M. showed decrement in all

the level of stress.

After six months practice of P.M. experimental group showed

significant (p < .0005) reduction in insecurity feelings compared to pre-

stage where as the control group remained at moderate level of

insecurity feelings.

The subjects of experimental group reduced their level of inferiority

feelings significantly (p < .0005) as compared to their pre-stage after

two and six both months of practice of meditation.

Mishra and Sharma (2011) studied effect of Preksha Meditation and yoga on

stress reaction and its management. They undertook total 130 subjects (65

male and 65 female) between the age group 25-45 years suffering from

chronic stress. The total duration of observation was 180 days. During this

study they found significant decline in blood pressure in both the male and

female subjects. A significant regular reduction was noted in heart rate, pulse

rate and respiratory rate in both the group of experimental group after the

(108)

regular practice of Preksha Meditation and Yoga module. Quantitative saliva

cortisol (stress hormone) level in subjects of experimental group decreased

significantly as compared to base line value after practice of Preksha

Meditation.

Mishra and Kapoor (2011) studied effect of Preksha Meditation in reducing

academic stress and enhancing emotional stability of adolescents. They

selected 100 female students in age group of 15-17 years. These all subjects

were divided into four groups, each of 25. Three groups were served as

experimental group. Subjects of these three groups were provided training

through three different Preksha Meditation techniques i.e. Kayotsarga, Jyoti

Kendra Preksha and Swas Preksha, whereas no training was given to control

group and they found that. Preksha Meditation can remove academic

pressure and anxiety, eliminates conflicts, enhances emotional stability and

vitalizes an individual for satisfactory performance in the area of student’s

work and relationship.

LACUNAE

As evident from review of literature it is known that quite a few studies are

available depicting the effect of the ongoing practices of various components

of meditation. But there is no systematic and scientific study demonstrating

the persistent of these changes in frequency of EEG waves in normal subject,

particularly Preksha Meditation. Methodological problems have plagued early

research and the multitude of meditation techniques examined make

generalization difficult. Thus present investigator was inspired to take this

research work for further exploration.

(109)

OBJECTIVES OF STUDY

1. The study aims to test scientifically the efficacy of Preksha Meditation

practice of four months on EEG waves.

2. To present obtained data scientifically, statistically and in duality form.

HYPOTHESES

Keeping in mind the various precautions and criteria necessary for formulating

a hypothesis, following hypotheses were formulated:

1. The subjects of experimental group subjected to Preksha Meditation

will show significant alteration in the 1st post-phase and again in the

2nd post-phase on alpha, beta, delta and theta waves.

2. The alpha waves, in the subject of experimental group will show an

increasing trend and beta will decrease.