P300 and Heart Rate Variability Recorded Simultaneously in Meditation.

Sympathetic activation is required for attention. Separate studies have shown that meditation ( a) improves attention and ( b) reduces sympathetic activity. The present study assessed attention with the P300 and sympathetic activity with heart rate variability (HRV). Forty-seven male subjects (group mean age ± SD, 21.6 ± 3.4 years) were assessed in 4 mental states: ( a) random thinking, ( b) nonmeditative focusing, ( c) meditative focusing, and ( d) defocused meditation. These were recorded on 4 consecutive days. HRV, respiration, and P300 event-related potentials (ERPs) were recorded before and after the sessions. Data were analyzed with repeated-measures analysis of variance followed by post hoc analysis. HRV showed a significant increase in low-frequency (LF) power, decrease in high-frequency (HF) power and an increase in average heart rate based on the average R-R interval after meditative focusing, compared with before. In contrast, the average heart rate decreased after defocused meditation compared with before. There was a significant increase in the P300 peak amplitude after meditative focusing and defocused meditation, with a reduction in peak latency after defocused meditation. These results suggest that after meditation with focusing, there was sympathetic arousal whereas after defocused meditation, there was a decrease in the average heart rate while participants carried out the P300 auditory oddball task sooner.

Amelioration of streptozotocin-induced type 2 diabetes mellitus in Wistar rats by arachidonic acid.

Traditionally arachidonic acid (AA, 20:4 n-6) is considered as a pro-inflammatory molecule since it forms precursor to prostaglandins (PGs), leukotrienes (LTs) and thromboxanes (TXs) that have pro-inflammatory actions. Type 2 diabetes mellitus (type 2 DM) is considered as a low-grade systemic inflammatory condition in which circulating PGs and LTs are increased. Streptozotocin (STZ)-induced type 2 DM is used as a model of human type 2 DM in which peripheral insulin resistance, increased plasma interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and hyperglycemia occurs. In the present study, we observed that oral supplementation of AA prevented STZ-induced type 2 DM in Wistar rats by restoring hyperglycemia, plasma levels of TNF-α and IL-6; adipose tissue NF-kB and lipocalin 2 (LPCLN2) and pancreatic tissue NF-kB and 5- and 12- lipoxygenase enzymes to normal. AA treatment enhanced insulin sensitivity and plasma lipoxin A4 (LXA4) levels, a potent anti-inflammatory molecule derived from AA. These results are supported by our previous studies wherein it was noted that plasma phospholipid content of AA and circulating LXA4 levels are low in those with type 2 DM. In a preliminary study, we also noted that high-fat-diet (HFD)-induced type 2 DM in Wistar rats can be prevented by oral supplementation of AA. These results suggest AA has anti-inflammatory and anti-diabetic actions by enhancing the production of its anti-inflammatory metabolite LXA4.

The effect of yoga on neuroticism in an Indian population varies with socio-demographic factors.

Neuroticism, or negative affectivity, can influence a person's approach to life. This study examined levels of neuroticism in 249 patients with illnesses known to be related to the mental state. All of them were given a six-day intensive yoga program. Patients showed a decrease in neuroticism measured by the PGI Health Questionnaire. The reduction was maximum for (a) those with ages between 36 and 51 years, (b) females, (c) patients with at least 17 years of education, and (d) those who were self-employed. The results show the importance of socio-demographic factors in neuroticism levels and in programs intended to reduce neuroticism. Hence, yoga is a useful intervention to reduce traits of neuroticism, with variations in the degree of change based on social factors.

Meditation and attention: a comment on a recent article.

Meditation and attention are considered associated in different ways. For example, contemporary concepts state that to meditate, a practitioner has either to (i) focus attention on the object of meditation (FA) or (ii) maintain vigilance and disengage their attention consciously from all distracters (OM). The Indian sage Patanjali (circa 900 B.C.), mentioned that there are two stages of meditation, which differ subtly from the descriptions of FA and OM. One stage is called dharana, or focusing attention on the object of meditation. Another stage is called dhyana, during which all thoughts remain effortlessly directed to the object of meditation, excluding all other thoughts. Vigilance and attention are not required during dhyana, which is the actual phase of meditation. In a previous study, participants who practiced dharana performed better in a task for selective attention than those who practiced dhyana. Brainstem auditory evoked potential changes during the two states differed. Descriptions of yoga practices from ancient texts can give added insights about meditation and attention, supported by objective assessments.

Effect of yoga on musculoskeletal discomfort and motor functions in professional computer users.

The self-rated musculoskeletal discomfort, hand grip strength, tapping speed, and low back and hamstring flexibility (based on a sit and reach task) were assessed in 291 professional computer users. They were then randomized as Yoga (YG; n=146) and Wait-list control (WL; n=145) groups. Follow-up assessments for both groups were after 60 days during which the YG group practiced yoga for 60 minutes daily, for 5 days in a week. The WL group spent the same time in their usual recreational activities. At the end of 60 days, the YG group (n=62) showed a significant decrease in the frequency, intensity and degree of interference due to musculoskeletal discomfort, an increase in bilateral hand grip strength, the right hand tapping speed, and low back and hamstring flexibility (repeated measures ANOVA and post hoc analysis with Bonferroni adjustment). In contrast, the WL group (n=56) showed an increase in musculoskeletal discomfort and a decrease in left hand tapping speed. The results suggest that yoga practice is a useful addition to the routine of professional computer users.

Yoga reduces symptoms of distress in tsunami survivors in the andaman islands.

A month after the December 2004 tsunami the effect of a 1 week yoga program was evaluated on self rated fear, anxiety, sadness and disturbed sleep in 47 survivors in the Andaman Islands. Polygraph recordings of the heart rate, breath rate and skin resistance were also made. Among the 47 people, 31 were settlers from the mainland (i.e. India, ML group) and 16 were endogenous people (EP group). There was a significant decrease in self rated fear, anxiety, sadness and disturbed sleep in both groups, and in the heart and breath rate in the ML group, and in the breath rate alone in the EP group, following yoga (P < 0.05, t-test). This suggests that yoga practice may be useful in the management of stress following a natural disaster in people with widely differing social, cultural and spiritual beliefs.

Effect of yoga on self-rated visual discomfort in computer users.

BACKGROUND: 'Dry eye' appears to be the main contributor to the symptoms of computer vision syndrome. Regular breaks and the use of artificial tears or certain eye drops are some of the options to reduce visual discomfort. A combination of yoga practices have been shown to reduce visual strain in persons with progressive myopia. The present randomized controlled trial was planned to evaluate the effect of a combination of yoga practices on self-rated symptoms of visual discomfort in professional computer users in Bangalore. METHODS: Two hundred and ninety one professional computer users were randomly assigned to two groups, yoga (YG, n = 146) and wait list control (WL, n = 145). Both groups were assessed at baseline and after sixty days for self-rated visual discomfort using a standard questionnaire. During these 60 days the YG group practiced an hour of yoga daily for five days in a week and the WL group did their usual recreational activities also for an hour daily for the same duration. At 60 days there were 62 in the YG group and 55 in the WL group. RESULTS: While the scores for visual discomfort of both groups were comparable at baseline, after 60 days there was a significantly decreased score in the YG group, whereas the WL group showed significantly increased scores. CONCLUSION: The results suggest that the yoga practice appeared to reduce visual discomfort, while the group who had no yoga intervention (WL) showed an increase in discomfort at the end of sixty days.

Changes in middle latency auditory evoked potentials during meditation.

In the present study of middle latency auditory evoked potentials during Brahmakumaris Raja Yoga meditation there was a decrease in the peak latency of the Na wave (a negative wave between 14 and 19 msec.) during meditation. Since the neural generator of this wave lies at the midbrain-thalamic level, from the results one can infer that the meditation reduces conduction time at this level.

An evaluation of the ability to voluntarily reduce the heart rate after a month of yoga practice.

The study aimed at determining whether novices to yoga would be able to reduce their heart rate voluntarily and whether the magnitude of reduction would be more after 30 days of yoga training. Two groups (yoga and control, n = 12 each) were assessed on Day 1 and on Day 30. During the intervening 30 days, the yoga group received training in yoga techniques while the control group carried on with their routine. At each assessment the baseline heart rate was recorded for one minute, this was followed by a six-minute period during which participants were asked to attempt to voluntarily reduce their heart rate, using any strategy. Both the baseline heart rate and the lowest heart rate achieved voluntarily during the six-minute period were significantly lower in the yoga group on Day 30 compared to Day 1 by a group average of 10.7 beats per minute (i.e., bpm) and 6.8 bpm, respectively (p < .05, Wilcoxon paired signed ranks test). In contrast, there was no significant change in either the baseline heart rate or the lowest heart rate achieved voluntarily in the control group on Day 30 compared to Day 1. The results suggest that yoga training can enable practitioners to use their own strategies to reduce the heart rate, which has possible therapeutic applications.

Sensory perception during sleep and meditation: common features and differences.

Sleep and meditation are both physiological conditions in which peripheral sensory input is voluntarily reduced, but sensory perception of internally generated information continues. However, the two conditions differ in the level of awareness retained.

Yoga breathing through a particular nostril increases spatial memory scores without lateralized effects.

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 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 4 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 yoga breathing increases spatial rather than verbal scores, without a lateralized effect.

Middle latency auditory evoked potentials in congenitally blind and normal sighted subjects.

Middle latency auditory evoked potentials were recorded in two groups of ten subjects each, viz, congenitally blind (CB) and age-matched subjects with normal vision (NV). The age range for both groups was 13 to 16 years. The CB group subjects had peripheral deficits, with absence of visual evoked responses. The peak latency of the Nb wave (the maximum negativity between 38 and 48 ms) was significantly lower in the CB group compared to NV group (p < .05, one-tailed, two factor ANOVA, Tukey test). In addition to these recordings from the vertex, recordings were also made from occipital areas, to test whether the visual cortex contributes to information processing at primary auditory cortical levels in the blind, as was reported in earlier studies on the generation of potentials during auditory selective attention. No such effect was observed. Hence, it appears that in blind subjects changes in generators of auditory middle latency evoked potentials are mainly related to latency, rather than to scalp distribution of these components.

Yoga for rehabilitation: an overview.

The use of yoga for rehabilitation has diverse applications. Yoga practice benefited mentally handicapped subjects by improving their mental ability, also the motor co-ordination and social skills. Physically handicapped subjects had a restoration of some degree of functional ability after practicing yoga. Visually impaired children children showed a significant decrease in their abnormal anxiety levels when they practiced yoga for three weeks, while a program of physical activity had no such effect. Socially disadvantaged adults (prisoners in a jail) and children in a remand home showed significant improvement in sleep, appetite and general well being, as well as a decrease in physiological arousal. The practice of meditation was reported to decrease the degree of substance (marijuana) abuse, by strengthening the mental resolve and decreasing the anxiety. Another important area is the application of yoga (and indeed, lifestyle change), in the rehabilitation of patients with coronary artery disease. Finally, the possible role of yoga in improving the mental state and general well being of HIV positive persons and patients with AIDS, is being explored.