Preksha Meditation & Human Health ► 2. Relevant Available Scientific Studies ► 4. Electroencephalograph (EEG) ► 4.2

Posted: 14.09.2015

Peper E (2006) Tongue piercing by a Yogi: QEEG observations This study reports on the QEEG observations recorded from a yogi during tongue piercing in which he demonstrated voluntary pain control. The QEEG was recorded with a Lexicor 1620 from 19 sites with appropriate controls for impedence and artifacts. A neurologist read the data for abnormalities and the QEEG was analyzed by mapping, single and multiple hertz bins, coherence, and statistical comparisons with a normative database. The session included a meditation baseline and tongue piercing. During the meditative baseline period the yogi's QEEG maps suggesting that he was able to lower his brain activity to a resting state. This state showed a predominance of slow wave potentials (delta) during piercing and suggested that the yogi induced a state that may be similar to those found when individuals are under analgesia. Further research should be conducted with a group of individuals who demonstrate exceptional self-regulation to determine the underlying mechanisms, and whether the skills can be used to teach others how to manage pain.

Jerath R (2006) Physiology of long pranayamic breathing: neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the autonomic nervous system Pranayamic breathing, defined as a manipulation of breath movement, has been shown to contribute to a physiologic response characterized by the presence of decreased oxygen consumption, decreased heart rate, and decreased blood pressure, as well as increased theta wave amplitude in EEG recordings, increased parasympathetic activity accompanied by the experience of alertness and reinvigoration. The mechanism of how pranayamic breathing interacts with the nervous system affecting metabolism and autonomic functions remains to be clearly understood. It is our hypothesis that voluntary slow deep breathing functionally resets the autonomic nervous system through stretch-induced inhibitory signals and hyperpolarization currents propagated through both neural and non-neural tissue which synchronizes neural elements in the heart, lungs, limbic system and cortex. During inspiration, stretching of lung tissue produces inhibitory signals by action of slowly adapting stretch receptors (SARs) and hyperpolarization current by action of fibroblasts. Both inhibitory impulses and hyperpolarization current are known to synchronize neural elements leading to the modulation of the nervous system and decreased metabolic activity indicative of the parasympathetic state. In this paper we propose pranayama's physiologic mechanism through a cellular and systems level perspective, involving both neural and non-neural elements. This theoretical description describes a common physiological mechanism underlying pranayama and elucidate the role of the respiratory and cardiovascular system on modulating the autonomic nervous system. Along with facilitating the design of clinical breathing techniques for the treatment of autonomic nervous system and other disorders, this model will also validate pranayama as a topic requiring more research.

Oken BS (2006) Randomized, controlled, six-month trial of yoga in healthy seniors: effects on cognition and quality of life.There are potential benefits of mind-body techniques on cognitive function because the techniques involve an active attentional or mindfulness component, but this has not been fully explored. To determine the effect of yoga on cognitive function, fatigue, mood, and quality of life in seniors. Randomized, controlled trial comparing yoga, exercise, and wait-list control groups. One hundred thirty-five generally healthy men and women aged 65-85 years. Participants were randomized to 6 months of Hatha yoga class, walking exercise class, or wait-list control. Subjects assigned to classes also were asked to practice at home.

Outcome assessments performed at baseline and after the 6-month period included a battery of cognitive measures focused on attention and alertness, the primary outcome measures being performance on the Stroop Test and a quantitative electroencephalogram (EEG) measure of alertness; SF-36 health-related quality of life; Profile of Mood States; Multi-Dimensional Fatigue Inventory,' and physical measures related to the interventions. One hundred thirty-five subjects were recruited and randomized. Seventeen subjects did not finish the 6-month intervention. There were no effects from either of the active interventions on any of the cognitive and alertness outcome measures. The yoga intervention produced improvements in physical measures (eg, timed 1-legged standing, forward flexibility) as well as a number of quality-of-life measures related to sense of well-being and energy and fatigue compared to controls. There were no relative improvements of cognitive function among healthy seniors in the yoga or exercise group compared to the wait-list control group. Those in the yoga group showed significant improvement in quality-of-life and physical measures compared to exercise and wait-list control groups.

Aftanas L (2005) Impact of regular meditation practice on EEG activity at rest and during evoked negative emotions. The main objective of the present investigation was to examine how long-term meditation practice is manifested in EEG activity 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 continuum 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. Although increasing arousal desynchronized activity in these bands in both groups, the theta-2 and alpha-1 power in the eyes-open period and alpha-1 power while viewing the neutral clip remained still higher in the SYM. 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 aversive movie clip yielded significant alpha desynchronization in both groups, reflecting arousing nature of emotional induction. In the control group along with alpha desynchronization affective 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.

Pal et al (2004) studied effect of short-term practice of breathing exercises on autonomic functions in normal human volunteer. The increased parasympathetic activity and decreased sympathetic activity were observed in slow breathing group, whereas no significant change in autonomic functions was observed in the fast breathing group. The findings of the present study showed that regular practice of slow breathing exercise for three months improves autonomic functions, while practice of fast breathing exercise for the same duration does not affect the autonomic functions.

Kannathal N (2004) Effect of reflexology on EEG—a nonlinear approach Reflexology is a 4000-year-old art of healing practiced in ancient India, China and Egypt. In the beginning of the 20th century, it spread to the Western world. Reflexologic clinics and massage centers can be found all around the world. In spite of the widespread popularity, to the best of our knowledge, no serious research work has been done in this area, although much scientific research work has been carried out in other Eastern techniques like meditation and yoga. This is why a humble attempt is done in this work to quantitatively assess the effect of reflexological stimulation from a systems point of view. In this work, nonlinear techniques have been used to assess the complexity of EEG with and without reflexological stimulation. We prefer the nonlinear approach, as we believe that the effects are taking place in a subtle way, since there is no direct correlation between reflexological points and modern neuroanatomy.

Anand et al (2003) studied effect of mukh bhastrika on reaction time and reported that yoga training improves human performance including central neural processing. Their earlier studies from their laboratories have shown that yoga training produces a significant decrease in visual reaction time and auditory time a decrease in RT indicates an improvement sensory-motor performance and enhanced processing ability of central nervous system. This may be due to greater arousal, faster rate of information processing improvement concentration and /or and ability to ignore extraneous stimuli.

Aftanas LI (2002) Non-linear dynamic complexity of the human EEG during meditation. We used non-linear analysis to investigate the dynamical properties underlying the EEG in the model of Sahaja Yoga meditation. Non-linear dimensional complexity (DCx) estimates, indicating complexity of neuronal computations, were analyzed in 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. It is suggested that meditative experience, characterized by less complex dynamics of the EEG, involves 'switching off irrelevant networks for the maintenance of focused internalized attention and inhibition of inappropriate information. 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.

Arambula et al (2001) in their study explored the physiological correlates of highly experienced kundalini yoga meditators. Thoracic and abdominal breathing patterns, heart rate (HR), occipital and parietal electroencephalograph (EEG), skin conductance level (SCL), and blood volume pulse (BVP) were monitored during prebaseline, meditation, and postbaseline periods. 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 postbaseline 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 microV) compared to the pre- (M =.47 µV) and postbaseline (M -.78 µV) periods, and an increase in theta EEG activity immediately following the meditation (M =.62 µV) compared to the pre-baseline and meditative periods (each with M =.26 µV). These findings suggest that a shift in breathing patterns may contribute to the development of alpha EEG.

Panjwani U (1999) The effect of Sahaja yoga meditation on seizure control and electroencephalographic alterations was assessed in 32 patients of idiopathic epilepsy. The subjects were randomly divided into 3 groups. Group I (n = 10) practised Sahaja yoga for 6 months, Group II (n - 10) practised 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. Sahaja yoga could prove to be beneficial in the management of patients of epilepsy.

Lou HC (1997) The aim of the present study was to examine whether the neural structures sub serving meditation can be reproducibly measured, and, if so, whether they are different from those supporting the resting state of normal consciousness. Cerebral blood flow distribution was investigated with the 150-H20 PET technique in nine young adults, who were highly experienced yoga teachers, during the relaxation meditation (Yoga Nidra), and during the resting state of normal consciousness. In addition, global CBF was measured in two of the subjects. Spectral EEG analysis was performed throughout the investigations. In meditation, differential activity was seen, with the noticeable exception of VI, in the posterior sensory and associative cortices known to participate in imagery tasks. In the resting state of normal consciousness (compared with meditation as a baseline) differential activity was found in dorso-lateral and orbital frontal cortex, anterior cingulate gyri, left temporal gyri, left inferior parietal lobule, striatal and thalamic regions, pons and cerebellar vermis and hemispheres, structures thought to support an executive attentional network. The mean global flow remained unchanged for both subjects throughout the investigation (39+/-5 and 38+/-4 ml/ 100 g/min, uncorrected for partial volume effects). It is concluded that the (H2)150 PET method may measure CBF distribution in the meditative state as well as during the resting state of normal consciousness, and that characteristic patterns of neural activity support each state. These findings enhance our understanding of the neural basis of different aspects of consciousness.

Sannyasi Sivagyana (Richard Budden) (1997) studied effects of pranayama on the Brain. He examines various prana nigraha practices, which contribute initially to changing the physiological state of the brain and are said to awaken prana in the realm of the chakras, or psychic centers, within the human body. A review of a medical examination of a yogic adept is included, which confirms the ability of Pranayama to influence an individual's brain activity. The conclusion is drawn that extensive prana nigraha practices leading into Pranayama can significantly influence the physical, pranic, mental and psychic aspects of the human brain. Four Pranayama practices are examined for their effects on the brain or other parts of the human body. While extensive Pranayama leads to significant control over the brain, prana nigraha practices carried out by the writer have affected subtle changes in ability to control both the breath and energy within the body. It is more difficult to detect any major effects on body physiology, but there has been a definite change in the state of one-pointedness and calmness of the mind over the past two years as result of the practices of four Pranayama.

Stancák A Jr, (1994) EEG changes during forced alternate nostril breathing. The effects of 10 min forced alternate nostril breathing (FANB) on EEG topography were studied in 18 trained subjects. One type of FANB consisted in left nostril inspiration and right nostril expiration and the other type in right nostril inspiration and left nostril expiration. Mean power in the beta bands and partially in the alpha band increased during FANB irrespective of the type of nostril breathing. In addition, hemisphere asymmetry in the beta 1 band decreased in the second half of FANB suggesting that FANB has a balancing effect on the functional activity of the left and right hemisphere.

Telles S (1993) This report presents the changes in various autonomic and respiratory variables during the practice of Brahmakumaris Raja yoga meditation. This practice requires considerable commitment and involves concentrated thinking. 18 males in the age range of 20 to 52 years (mean 34.1 +/- 8.1), with 5-25 years experience in mediation (mean 10.1 +/- 6.2), participated in the study. Each subject was assessed in three test sessions which included a period of meditation, and also in three control (non-mediation) sessions, which included a period of random thinking. Group analysis 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.

On an individual basis, changes which met the following criteria were noted: (1), changes which were greater during meditation (compared to its preceding baseline) than changes during post meditation or non-meditation periods (also compared to their preceding baseline); (2), Changes which occurred consistently during the three repeat sessions of a subject and (3), changes which exceeded arbitrarily-chosen cut-off points (described at length below). This individual level analysis revealed that changes in autonomic variables suggestive of both activation and relaxation occurred simultaneously in different subdivisions of the autonomic nervous system in a subject. Apart from this, there were differences in patterns of change among the subjects who practised the same meditation.

Satyanarayana et al (1992) conducted a study on Santhi Kriya's effect and reported that santhi kriya is a mixture of combined yogic practices of breathing and relaxation. Preliminary attempts were made to determine the effect of santhi kriya on certain psychophysiological parameters. Eight healthy male volunteers of the age group 25.9 +/- 3 (SD) years were subjected to santhi kriya practice daily for 50 minutes for 30 days. The volunteer's body weight, blood pressure, oral temperature, pulse rate, respiration, ECG and EEG were recorded before and after the practice on the 1st day and subsequently on 10th, 20th and 30th day of their practice. They were also given a perceptual acuity test to know their cognitive level on the 1st day and also at the end of the study i.e., on the 30th day. Results indicate a gradual and significant decrease in the body weight from 1st to 30th day (P less than 0.001) and an increase in alpha activity of the brain (P less than 0.001) during the course of 30 days of santhi kriya practice. Increase of alpha activity both in occipital and pre-frontal areas of both the hemispheres of the brain denotes an increase of calmness. This study also revealed that santhi kriya practice increases oral temperature by 3 degrees F and decreases respiratory rate significantly (P less than 0.05) on all practice days. Other parameters were not found to be altered significantly. It is concluded that the santhi kriya practice for 30 days reduces body weight and increases calmness.

Stancák A Jr (1991) Kapalabhati—yogic cleansing exercise. II. EEG topography Topography of brain electrical activity was studied in 11 advanced yoga practitioners during yogic high-frequency breathing kapalabhati (KB). Alpha activity was increased during the initial five min of KB. Theta activity mostly in the occipital region was increased during later stages of 15 min KB compared to the pre-exercise period. Beta 1 activity increased during the first 10 min of KB in occipital and to a lesser degree in parietal regions. Alpha and beta 1 activity decreased and theta activity was maintained on the level of the initial resting period after KB. The score of General Deactivation factor from Activation Deactivation Adjective Checklist was higher after KB exercise than before the exercise. The results suggest a relative increase of slower EEG frequencies and relaxation on a subjective level as the after effect of KB exercise.

An important difference between yogic bellows-type breathing like mukh bhastrika or kapalabhati and hyperventilation is that prolonged hyperventilation produces abnormal EEG changes whereas there are no abnormal EEG changes even after 10 minutes of kapalabhati. The study done by Gore et al (1989).

Orme-Johnson DW (1988) Topographic EEG brain mapping during Yogic Flying. Voluntary focal activity typically disrupts EEG alpha activity. This experiment tested the hypothesis that the alpha wave would not be disrupted during "Yogic Flying" (YF), a TM-Sidhi technique that produces movement of the body such as hopping, because the technique operates at a self-referral level in which attention remains in a settled, inwardly directed state. In 23 subjects YF was compared with voluntary jumping in the same subjects which mimicked the movements of YF. The percentage of relative power of alpha was significantly higher for YF in virtually all EEG derivations, supporting the hypothesis. The effect appeared to be of similar magnitude in all cortical areas.

Zhang JZ (1988) Wallace first reported the changes in EEG during transcendental meditation [6], Banquet [1] observed, on the basis of spectral analysis of the EEG, that the mediation state was a unique state of consciousness, and separate from wakefulness, drowsiness or sleep. The Qi Gong of China is not the same as either transcendental meditation or the Yoga Gong. The EEG during Qi Gong state is clearly different from those recorded during the resting state. The changes in the EEG during the Qi Gong have not been reported previously. The EEG alpha activity during the Qi Gong state occurs predominantly in the anterior regions. The peak frequency of EEG alpha rhythm is slower than the resting state. The change of EEG during Qi Gong between anterior and posterior half is negative correlation. These changes are statistically significant.

While investigating Changes in serum glutamate oxaloacetate transaminase enzyme activity after one minute kapalabhati, Desai et. al. (1987) has shown that the SGOT enzyme activity before and after one minute practice of kapalabhati (2, 4 - dinitrophenyl hydrazine method) the subjects having high enzyme activity showed decrease and the subjects having low values showed an increase in the enzyme activity.

Shrikrishna (1985) has scientifically investigated the essence of pranayama and stated that different practices of pranayama do show widespread effects on the various body functions and the changes in the respiratory, cardio-vascular, biochemical, metabolic, and neural functions. The changes in all pranayama practices lead to identical neural response in the form of increased Alpha pattern of the brain waves seen in EEG. This increase in alpha waves all over the brain is called synchronization and it was always more when objects reported a subjective feeling of more mental calmness and alert restfulness.

Roldán E (1985) studied EEG patterns suggestive of shifted levels of excitation effected by hathayogic exercises Concurrent with the performance of hathayogic exercises such as Nauli, bhastrika and suryabhedana, three characteristic EEG patterns were identified: a "wicket" rhythm at a frequency wave of 12 to 17 Hz, recordable from para-Rolandic areas, which we have called Xi rhythm; a 26-33 Hz sinusoidal activity, confined to the mid-sagittal parietooccipital region; and paroxysmal activity localized in the lateral boundaries of parieto-temporo-occipital regions, bilaterally. - The expectation that hathayogic exercises would affect the electrical activity of circumscribed, relatively well defined areas of the brain was based on the fact that these exercises imply a strong stimulation of somatic and splanchnic receptors, the afferent impulses of which are fed into specific cortical representation areas localized for the most part around central and anterior parietal areas.

WoolfolkRL (1975) Psycho-physiological correlates of meditation. The scientific research that has investigated the physiological changes associated with meditation as it is practiced by adherents of Indian Yoga, Transcendental Meditation, and Zen Buddhism has not yielded a thoroughly consistent, easily replicable pattern of responses. The majority of studies show meditation to be a wakeful state accompanied by a lowering of cortical and autonomic arousal. The investigations of Zen and Transcendental Meditation have thus far produced the most consistent findings. Additional research into the mechanisms underlying the phenomena of meditation will require a shifting from old to new methodological perspectives that allow for adequate experimental control and the testing of theoretically relevant hypotheses.

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