The effect of voluntary breathing on reaction time

Effect of 12 Weeks of Yogic Training on Neurocognitive Variables: A Quasi-Experimental Study

BACKGROUND

Neurocognitive abilities are the brain-mind skills needed to initiate any task from the simplest to the most complex, decreases with advancing age. Attention, alertness, and memory are the basic neurocognitive functions most affected by age. There are potential benefits of yoga on neurocognitive functions because this ancient Indian technique positively nurtures the mind-body systems.

AIM OF THE STUDY

The present study was aimed to evaluate the effect of 12 weeks of yogic training on neurocognitive abilities in a middle-aged group.

METHODS

A total of 86 volunteers (46 male and 40 females, age group of 35-55 years), with no prior experience of yoga were participated in this study. Five male and 4 female participants were excluded from the study. All participants divided into yoga training group (male = 21 and female = 18) and control group (male = 20 and female = 18). The yoga training group underwent yoga practices, including kriya, surya namaskar, asana, pranayama, and dhyana daily in the morning, for 6 days/week, for 12 weeks. Standing height, body weight, body mass index, visual reaction time (RT), auditory RT (attention and alertness), and short-term memory were assessed day 1 (pre), 6th week (mid), and 12th weeks (post) of intervention.

RESULTS

Repeated-measures analysis of variance showed that a statistically significant increased (P < 0.05) in attention-alertness and short-term memory after 12 weeks of yogic practices.

CONCLUSION

Integrated approach of yogic intervention may have promising effect on neurocognitive abilities that concomitantly promote successful aging.

Differential effects of uninostril and alternate nostril pranayamas on cardiovascular parameters and reaction time

BACKGROUND

Recent studies have reported the differential physiological and psychological effects of yogic uninostril breathing (UNB) and alternate nostril breathing (ANB) techniques. This study aims to determine differential effects of these techniques on reaction time (RT), heart rate (HR), and blood pressure (BP).

MATERIALS AND METHODS

Twenty yoga-trained subjects came to the lab on six different days and RT, HR, and BP were recorded randomly before and after nine rounds of right UNB (surya nadi [SN]), left UNB (chandra nadi [CN]), right initiated ANB (surya bhedana [SB]), left initiated ANB (chandra bhedana [CB]), nadi shuddhi (NS), and normal breathing (NB).

RESULTS

Overall comparison of ∆ % changes showed statistically significant differences between groups for all parameters. There was an overall reduction in HR- and BP-based parameters following CB, CN, and NS with concurrent increases following SB and SN. The differential effects of right nostril initiated (SB and SN) and left nostril initiated (CB, CN, and NS) UNB and ANB techniques were clearly evidenced. Changes following NB were insignificant in all respects. The overall comparison of ∆ % changes for RT showed statistically significant differences between groups that were significantly lowered following both SB and SN.

DISCUSSION AND CONCLUSION

Our study provides evidence of sympathomimetic effects of right nostril initiated pranayamas with sympatholytic/parasympathomimetic effect following left nostril initiated pranayamas. We suggest that the main effect of UNB and ANB techniques is determined by the nostril used for inspiration rather than that used for expiration. We conclude that right and left yogic UNB and ANB techniques have differential physiological effects that are in tune with the traditional swara yoga concept that air flow through right nostril (SN and pingala swara) is activatory in nature, whereas the flow through left nostril (CN and ida swara) is relaxatory.

Does the supplementary motor area keep patients with Ondine's curse syndrome breathing while awake?

BACKGROUND

Congenital central hypoventilation syndrome (CCHS) is a rare neuro-respiratory disorder associated with mutations of the PHOX2B gene. Patients with this disease experience severe hypoventilation during sleep and are consequently ventilator-dependent. However, they breathe almost normally while awake, indicating the existence of cortical mechanisms compensating for the deficient brainstem generation of automatic breathing. Current evidence indicates that the supplementary motor area plays an important role in modulating ventilation in awake normal humans. We hypothesized that the wake-related maintenance of spontaneous breathing in patients with CCHS could involve supplementary motor area.

METHODS

We studied 7 CCHS patients (5 women; age: 20-30; BMI: 22.1 ± 4 kg.m(-2)) during resting breathing and during exposure to carbon dioxide and inspiratory mechanical constraints. They were compared with 8 healthy individuals. Segments of electroencephalographic tracings were selected according to ventilatory flow signal, from 2.5 seconds to 1.5 seconds after the onset of inspiration. After artefact rejection, 80 or more such segments were ensemble averaged. A slow upward shift of the EEG signal starting between 2 and 0.5 s before inspiration (pre-inspiratory potential) was considered suggestive of supplementary motor area activation.

RESULTS

In the control group, pre-inspiratory potentials were generally absent during resting breathing and carbon dioxide stimulation, and consistently identified in the presence of inspiratory constraints (expected). In CCHS patients, pre-inspiratory potentials were systematically identified in all study conditions, including resting breathing. They were therefore significantly more frequent than in controls.

CONCLUSIONS

This study provides a neurophysiological substrate to the wakefulness drive to breathe that is characteristic of CCHS and suggests that the supplementary motor area contributes to this phenomenon. Whether or not this "cortical breathing" can be taken advantage of therapeutically, or has clinical consequences (like competition with attentional resources) remains to be determined.

Effects of abdominal and thoracic breathing upon multiple-site electromyography and peripheral skin temperature

Peripheral finger temperature, frontalis and upper trapezius EMG, and self-report of arousal were assessed for four subjects during abdominal and thoracic breathing in a single-subject reversal design. Two subjects displayed significant differences between abdominal and thoracic breathing conditions; one for frontalis EMG, trapezius EMG, and self-report of arousal and one for trapezius EMG. Two subjects showed no significant effects. All subjects reached performance criteria during training sessions. Abdominal breathing performance during reversals was 100% and 92% of sampled breath cycles for the two subjects who showed significant change, and 65% and 42% for the two subjects who showed none. Methodological issues for measurement of breathing patterns and peripheral skin temperature are discussed.

Ventilatory conditioning by self-stimulation in rats: a pilot study

This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rewarded by an electrical stimulation of the medial forebrain bundle whenever inspiratory duration (TI) exceeded 300 ms. A bidirectional control was then used: TIs longer than 400 ms were rewarded, and then TIs shorter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but after prolonged conditioning, the brain stimulation was associated with quiet wakefulness. Although the general procedure appears to be well-suited to the experimental study of voluntary breathing, some possible improvements are suggested for further, more extensive investigations.

Performance and learning during voluntary control of breath patterns

Fourteen subjects learned to adjust their breath pattern to two target breaths displayed on a video screen, by using visual feedback, during two sessions 24 h apart. These two targets were respectively the smallest and the largest breaths of a ten-breath sample previously recorded from each subject's resting spontaneous breathing. Performances were significantly better for the large than for the small target breath. This cannot be directly inferred from current knowledge related to the control of movement time and amplitude, but rather it may be inferred from the periodic character of breathing, to the higher mental load during the small breath task, or to the presumably different frequencies of target breaths in the whole span of spontaneous breathing. In the second session, performance on the two targets levelled out as a result of learning.