Search

Attention was influenced by yoga breathing in previously published research. Each yoga breathing practice uniquely modifies specific breath characteristics. Differences in the study designs, assessment methods and interventions resulted in difficulty in comparing effects between yoga breathing practices. This study aimed (i) to compare four yoga breathing practices on attention using an auditory oddball task and (ii) to determine cardiac autonomic activity associated with attention using heart rate variability. P300 event related potential was recorded simultaneously with heart rate variability before and after 18-minute periods each of (i) high frequency yoga breathing (with increased breath frequency), (ii) bellows yoga breathing (with increased depth of respiration), (iii) alternate nostril yoga breathing (with alternate nostril patency), (iv) bumblebee yoga breathing (with prolonged exhale), (v) breath awareness (with attention to the breath) and (vi) quiet seated rest as control in 38 yoga experienced males (average age ±  SD ; 24.08 ± 4.01 years). The six sessions were on separate, randomly allocated days. The P300 peak amplitude recorded at Pz was significantly increased after four yoga breathing practices (Bonferroni adjusted post-hoc tests, repeated measures ANOVA). No significant changes were noted in heart rate variability following yoga breathing or control sessions. These findings suggest that the four yoga breathing practices increase the attentional neural resources engaged for this auditory oddball task, irrespective of the characteristic of breath uniquely regulated in the four yoga breathing practices.

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.

The auditory sensory pathway has been studied in meditators, using midlatency and short latency auditory evoked potentials. The present study evaluated long latency auditory evoked potentials (LLAEPs) during meditation. Sixty male participants, aged between 18 and 31 years (group mean±SD, 20.5±3.8 years), were assessed in 4 mental states based on descriptions in the traditional texts. They were (a) random thinking, (b) nonmeditative focusing, (c) meditative focusing, and (d) meditation. The order of the sessions was randomly assigned. The LLAEP components studied were P1 (40-60 ms), N1 (75-115 ms), P2 (120-180 ms), and N2 (180-280 ms). For each component, the peak amplitude and peak latency were measured from the prestimulus baseline. There was significant decrease in the peak latency of the P2 component during and after meditation (P<.001; analysis of variance and post hoc analysis with Bonferroni adjustment). The P1, P2, and N2 components showed a significant decrease in peak amplitudes during random thinking (P<.01; P<.001; P<.01, respectively) and nonmeditative focused thinking (P<.01; P<.01; P<.05, respectively). The results suggest that meditation facilitates the processing of information in the auditory association cortex, whereas the number of neurons recruited was smaller in random thinking and non-meditative focused thinking, at the level of the secondary auditory cortex, auditory association cortex and anterior cingulate cortex., (© EEG and Clinical Neuroscience Society (ECNS) 2014.)