Yoga breathing through a particular nostril is associated with contralateral event-related potential changes.

BACKGROUND: In earlier studies uninostril yoga breathing was shown to influence the activity of the cerebral hemispheres differently, based on (i) auditory evoked potentials recorded from bilateral scalp sites, and (ii) performance in hemisphere-specific tasks. But change in P300 (event-related potential generated when subjects attend to and discriminate between stimuli) from bilateral scalp sites when subjects were practicing uni- and alternate-nostril breathing are yet to be explored. AIM: The present study was designed to determine whether or not immediately after uninostril or alternate nostril yoga breathing there would be a change in the ability to pay attention to a given stimulus. MATERIALS AND METHODS: Twenty-nine healthy male volunteers, with ages between 20 and 45 years were randomly allocated to five sessions, viz., (i) right-, (ii) left-, (iii) alternate-nostril yoga breathing, (iv) breath awareness and (v) no intervention, each for 45 min on separate days. The P300 event related potential was recorded using an auditory oddball paradigm from sites on the left (C3) and right (C4), referenced to linked earlobes, before and after each session. RESULTS: Post-hoc analysis with Bonferroni adjustment showed that the P300 peak latency was significantly lower at C3 compared to that at C4, following right nostril yoga breathing (P<0.05). CONCLUSION: These results suggest that right nostril yoga breathing facilitates the activity of contralateral (left) hemisphere, in the performance of the P300 task.

Post traumatic stress symptoms and heart rate variability in Bihar flood survivors following yoga: a randomized controlled study.

BACKGROUND: An earlier study showed that a week of yoga practice was useful in stress management after a natural calamity. Due to heavy rain and a rift on the banks of the Kosi river, in the state of Bihar in north India, there were floods with loss of life and property. A week of yoga practice was given to the survivors a month after the event and the effect was assessed. METHODS: Twenty-two volunteers (group average age +/- S.D, 31.5 +/- 7.5 years; all of them were males) were randomly assigned to two groups, yoga and a non-yoga wait-list control group. The yoga group practiced yoga for an hour daily while the control group continued with their routine activities. Both groups' heart rate variability, breath rate, and four symptoms of emotional distress using visual analog scales, were assessed on the first and eighth day of the program. RESULTS: There was a significant decrease in sadness in the yoga group (p < 0.05, paired t-test, post data compared to pre) and an increase in anxiety in the control group (p < 0.05, paired t-test, post data compared to pre). CONCLUSIONS: A week of yoga can reduce feelings of sadness and possibly prevent an increase in anxiety in flood survivors a month after the calamity. TRIAL REGISTRATION: Clinical Trials Registry of India: CTRI/2009/091/000285.

Risk of posttraumatic stress disorder and depression in survivors of the floods in Bihar, India.

BACKGROUND: Following a natural disaster, survivors are vulnerable to develop posttraumatic stress disorder (PTSD) and/ or depression. OBJECTIVES: (i) To screen survivors of the Bihar floods a month after the event to determine their scores in a screening questionnaire for PTSD and/ or depression and (ii) to correlate these scores with age and gender. MATERIALS AND METHODS: One thousand two hundred eighty-nine persons (645 females) who had been directly exposed to the floods in Bihar, India, in August 2008 were assessed. The Screening Questionnaire for Disaster Mental Health (SQD) was used to screen for PTSD and depression. STATISTICAL ANALYSIS: Separate two-factor ANOVAs were used to compare persons of both sexes and 5 different age groups for PTSD and depression scores. This was followed by post-hoc analysis for multiple comparisons. RESULTS: People over the age of 60 years had significantly higher scores for PTSD and depression compared to all groups (P< 0.05 for all comparisons). CONCLUSION: Following a natural disaster, older people appear more vulnerable to develop PTSD and depression. This should be taken into account in devising strategies for disaster relief.

Effect of four voluntary regulated yoga breathing techniques on grip strength.

Bilateral hand-grip strength was studied in 21 male volunteers (M age = 25.6 yr., SD = 5.2). All were assessed before and after five practice sessions of 20 min. duration: right-nostril yoga breathing, left-nostril yoga breathing, alternate-nostril yoga breathing, breath awareness, and a no-intervention session. Data were analyzed with analyses of variance and an analysis of variance using the no-breath awareness control condition as a covariate. There were no significant changes. The left-hand-grip strength reduced after left-nostril yoga breathing. However, findings were not considered significant, so methodological issues in yoga research which could contribute to null findings and even mask actual changes were discussed.

A nonrandomized non-naive comparative study of the effects of kapalabhati and breath awareness on event-related potentials in trained yoga practitioners.

OBJECTIVES: The study was conducted to compare the P300 event-related potentials recorded before and after (1) high-frequency yoga breathing (HFYB) and (2) breath awareness. DESIGN: The P300 was recorded in participants of two groups before and after the intervention session (1 minute in duration). SETTINGS AND LOCATION: All participants were receiving yoga training in a residential yoga center, Swami Vivekanada Yoga Research Foundation in Bangalore, India. SUBJECTS: Thirty (30) male participants formed two groups (n = 15 each) with comparable ages (within an age range of 20-35 years) and comparable experience of the two techniques, the minimum experience being 3 months. INTERVENTIONS: The two groups were each given a separate intervention. One group practiced a HFYB at a frequency of approximately 2.0 Hz, called kapalabhati. The other group practiced breath awareness during which participants were aware of their breath while seated, relaxed. OUTCOME MEASURES: The P300 event-related potential, which is generated when attending to and discriminating between auditory stimuli, was recorded before and after both techniques. RESULTS: The P300 peak latency decreased after HFYB and the P300 peak amplitude increased after breath awareness. CONCLUSIONS: Both practices (HFYB and Breath awareness), though very different, influenced the P300. HFYB reduced the peak latency, suggesting a decrease in time needed for this task, which requires selective attention. Breath awareness increased the P300 peak amplitude, suggesting an increase in the neural resources available for the task.

Immediate effects of right and left nostril breathing on verbal and spatial scores.

The immediate effect of two yoga breathing techniques was assessed on verbal and spatial memory tasks, considered hemisphere-specific. Forty-five participants (24 males; age range 20 to 45 years (mean age 27.1 +/- 8.1 years) were randomly allocated to three groups (n = 15 each) and were assessed immediately before and after 45 minutes of three breathing practices i.e., right nostril yoga breathing, left nostril yoga breathing, or breath awareness as a control intervention. Spatial memory scores increased after left nostril yoga breathing compared to before (by 16 percent, P = 0.03, paired t-test). Hence, breathing through the left nostril increased performance in a spatial cognitive task, corresponding to the cerebral hemisphere contralateral to the patent nostril.

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.