Effect of uninostril yoga breathing on brain hemodynamics: A functional near-infrared spectroscopy study

Breathing Right… or Left! The Effects of Unilateral Nostril Breathing on Psychological and Cognitive Wellbeing: A Pilot Study

The impact of controlled breathing on cognitive and affective processing has been recognized since ancient times, giving rise to multiple practices aimed at achieving different psychophysical states, mostly related to mental clarity and focus, stress reduction, and relaxation. Previous scientific research explored the effects of forced unilateral nostril breathing (UNB) on brain activity and emotional and cognitive functions. Some evidence concluded that it had a contralateral effect, while other studies presented controversial results, making it difficult to come to an unambiguous interpretation. Also, a few studies specifically addressed wellbeing. In the present study, we invited a pilot sample of 20 participants to take part in an 8-day training program for breathing, and each person was assigned to either a unilateral right nostril (URNB) or left nostril breathing condition (ULNB). Then, each day, we assessed the participants' wellbeing indices using their moods and mind wandering scales. The results revealed that, after the daily practice, both groups reported improved wellbeing perception. However, the effect was specifically related to the nostril involved. URNB produced more benefits in terms of stress reduction and relaxation, while ULNB significantly and increasingly reduced mind-wandering occurrences over time. Our results suggest that UNB can be effectively used to increase wellbeing in the general population. Additionally, they support the idea that understanding the effects of unilateral breathing on wellbeing and cognition requires a complex interpretive model with multiple brain networks to address bottom-up and top-down processes.

Neural correlates of breath work, mental imagery of yoga postures, and meditation in yoga practitioners: a functional near-infrared spectroscopy study

Objective

Previous research has shown numerous health benefits of yoga, a multicomponent physical and mental activity. The three important aspects of both traditional and modern yoga are breath work, postures, and meditation. However, the neural mechanisms associated with these three aspects of yoga remain largely unknown. The present study investigated the neural underpinnings associated with each of these three yoga components in long- and short-term yoga practitioners to clarify the neural advantages of yoga experience, aiming to provide a more comprehensive understanding of yoga's health-promoting effects.

Methods

Participants were 40 Chinese women, 20 with a long-term yoga practice and 20 with a short-term yoga practice. Functional near-infrared spectroscopy was conducted while participants performed abdominal breathing, mental imagery of yoga postures, and mindfulness meditation. The oxygenated hemoglobin concentrations activated in the brain during these three tasks were used to assess the neural responses to the different aspects of yoga practice. The self-reported mastery of each yoga posture was used to assess the advantages of practicing yoga postures.

Results

Blood oxygen levels in the dorsolateral prefrontal cortex during breath work were significantly higher in long-term yoga practitioners than in short-term yoga practitioners. In the mental imagery of yoga postures task, self-reported data showed that long-term yoga practitioners had better mastery than short-term practitioners. Long-term yoga practitioners demonstrated lower activation in the ventrolateral prefrontal cortex, with lower blood oxygen levels associated with performing this task, than short-term yoga practitioners. In the mindfulness meditation task, blood oxygen levels in the orbitofrontal cortex and the ventrolateral prefrontal cortex were significantly higher in long-term yoga practitioners than in short-term yoga practitioners.

Conclusion

The three core yoga components, namely, yogic breathing, postures, and meditation, showed differences and similarities in the activation levels of the prefrontal cortex. Long-term practice of each component led to the neural benefits of efficient activation in the prefrontal cortex, especially in the dorsolateral prefrontal cortex, orbitofrontal cortex, and ventrolateral prefrontal cortex.

Cerebral Haemodynamic Changes in Type 2 Diabetes Mellitus Following a Three-Month Yoga Intervention: A Randomized Controlled Trial

Background and purpose Cerebral haemodynamics and cognitive performance may be adversely affected in type 2 diabetes mellitus (T2DM). Previous studies reported reduced cerebral blood flow (CBF) and altered cerebrovascular reactivity (CVR) in T2DM. Yoga, an ancient holistic health approach, is known to be beneficial for T2DM. We hypothesized that yoga practice may alter CBF and the flow resistance in the middle cerebral artery (MCA) and improve cognition in T2DM. Our secondary objective was to explore the relationship between changes in cerebral haemodynamics and cognition in T2DM. Materials and methods Participants were randomly allotted into the yoga and control groups based on the eligibility criteria. One hour of yoga intervention specific to type 2 diabetes was provided to the yoga group for three months, while conventional treatment was provided to the control group. A transcranial Doppler was used to evaluate longitudinal changes in cerebral haemodynamics in MCA. A Corsi block tapping test was used to assess visio-spatial working memory. Results There were 75 participants recruited, of whom 38 participated in yoga and 37 participated in a control group. Both intention to treat and per protocol analysis showed significant results. At day 90, intention-to-treat analysis showed significant changes in CBF velocities (mean difference -10.85%, 95% CI (-13.26, -6.15), p<0.001), cerebral vasodilatory reserve (mean difference -0.23%, 95% CI (-0.43, -0.03), p=0.02) and cognition (mean difference -12.13%, 95% CI (-17.48, -6.78), p≤0.001). There was no between-group effect. Also, the correlation between the CBF and cognition did not show any significant results. Conclusion The three-month yoga intervention was associated with an improvement in cerebral hemodynamics. The study also revealed an improvement in visio-spatial working memory among patients with T2DM. The study did not show any correlation between the improvement in cerebral haemodynamics and working memory. We recommend larger and longer studies on yoga intervention for T2DM patients to evaluate whether such benefits are sustained and improve their quality of life.

The Effect of Specific Techniques of Nasal Breathing [Pranayama] on Intra-Ocular Pressure in Normal Individuals, a Randomized Trial

PURPOSE

Glaucoma is an optic neuropathy where intraocular pressure is the only modifiable risk factor. Yoga is thought to adversely affect intra-ocular pressure (IOP) but we do not know if yogic breathing exercises can influence IOP. With this study, we aimed to determine the effect of specific nasal breathing techniques on intra-ocular pressure in normal individuals.

PATIENTS AND METHODS

One hundred and sixty-four normal subjects were randomly assigned to one of four specific breathing groups - right nostril breathing (RNB), left nostril breathing (LNB), alternate nostril breathing (ANB), normal breathing (NB). The IOP was measured in both eyes at baseline and following the breathing exercise; and the change was analyzed.

RESULTS

Eighty-five women and 79 men participated and there was no significant difference in baseline age or IOP between the groups. In RNB, IOP reduced significantly in both right and left eyes, from 14.3 ± 3.0mmHg to 13.9 ± 2.6mmHg, (p=0.022) and from 14.7 ± 3.2mmHg to 14.2 ± 3mmHg (p=0.016) respectively. In LNB, there was no significant IOP change in the right eye, whereas in the left eye, there was a significant reduction from 14.2 ± 2.7mmHg to 13.3 ± 2.5mmHg (p< 0.0001). There was no significant IOP change in ANB and NB.

CONCLUSION

Specific breathing techniques like right and left nostril breathing, alternate nostril breathing are safe and do not raise IOP in normal subjects. Additionally, right and left nostril breathing techniques have a beneficial effect of lowering IOP.

Slow yoga breathing improves mental load in working memory performance and cardiac activity among yoga practitioners

This study investigated the immediate effect of slow yoga breathing (SYB) at 6 breaths per minute (bpm) simultaneously on working memory performance and heart rate variability (HRV) in yoga practitioners. A total of 40 healthy male volunteers performed a working memory task, ‘n-back’, consisting of three levels of difficulty, 0-back, 1-back, and 2-back, separately, before and after three SYB sessions on different days. The SYB sessions included alternate nostril breathing (ANB), right nostril breathing (RNB), and breath awareness (BAW). Repeated measures analysis of variance showed a significant reduction in reaction time (ms) in 2-back condition immediately after ANB (−8%), RNB (−8%) and BAW (−5%) practices. Similarly, the accuracy was improved in the 0-back condition after RNB (4%), and in the 2-back condition after ANB (6%) and RNB (6%) practices. These results suggest that SYB practice enhances cognitive abilities (8–9%) related to memory load and improves the functioning of cardiac autonomic activity, which is required for the successful completion of mental tasks.Trial registered in the Clinical Trials Registry of India (CTRI/2018/01/011132).

Immediate autonomic changes during right nostril breathing and left nostril breathing in regular yoga practitioners

BACKGROUND

The ancient Indian science of Yoga makes use of voluntary regulation of breathing to make respiration rhythmic and calm the mind. This practice is called pranayama. Nadisuddhi pranayama means "purification of subtle energy paths," inhalation and exhalation are through alternative nostrils for successive respiratory cycles. Surya Anuloma-Viloma pranayama means "heat generating breathing particle" when the respiratory cycle of inhalation and exhalation is completed through the right nostril exclusively. When completed through the left nostril alone, the practice is called "Chandra Anuloma-Viloma pranayama," which means a heat-dissipating or cooling liberating practice. We compared the effect of right nostril breathing (RNA) and left nostril breathing (LNB) pranayama on heart rate variability.

MATERIALS AND METHODS

The study was conducted at the Department of Physiology at an institute of national importance, after obtaining necessary ethical approvals from the Institutional Ethics Committee. Twenty healthy kriya yogi volunteers (mean age: 44 years), who are regular practitioners for the last 10-20 years, were inducted into the study. RNB pranayama starts with closing the right nostril with the thumb of the left hand followed by exhalation through the right nostril and inhaling slowly through the same nostril. This forms one round of RNB pranayama. In contrast, inhalation through the left nostril and exhalation through the right nostril exclusively is called chandrabhedana pranayama (chandrabhedana means moon-piercing breath in Sanskrit) with a similar variation called Chandra Anuloma-Viloma pranayama in which inhalation, as well as exhalation, is performed through the left nostril exclusively. The recording of electrocardiogram (ECG) for heart rate variability (HRV) analysis was taken by heart rate variability (Dinamika HRV-Advanced Heart Rate Variability Test System, Moscow, Russia). The resting and during readings of heart rate variability parameters were compared and post hoc analysis was done using Bonferroni and Holm multiple comparisons for repeated measures.

RESULTS

Time domain parameters: Standard deviation of normal to normal RR intervals (SDNN) and root mean square of successive NN interval differences (RMSSD) were increased at a high level of statistical significance during both pranayama maneuvres. Frequency domain parameters: LF, LF/HF ratio increased significantly. Parasympathetic activity is represented by LF when the respiration rate is lower than 7 breaths per min or during taking a deep breath. Thus, when the subject is in a state of relaxation with slow and even breathing in both RNB-right nostril and Chandra-LNB, the LF values can be very high, indicating an increase in parasympathetic activity rather than an increase in sympathetic regulation.

CONCLUSION

Our study is an acute study, where changes in HRV were seen after 5 min of RNB and LNB. However, statistically, there is not much difference in the immediate effects of the two pranayamas on heart rate variability in regular yoga practitioners.

Online Yoga and Ayurveda Intervention as Tertiary Prevention of Psychological Comorbidities in COVID-19 Survivors: A Randomized Controlled Trial

Background and Purpose

About 56% of symptomatic COVID-19 survivors have been found with neuropsychological comorbidities, such as depression, anxiety, posttraumatic stress disorders (PTSD), and impaired quality of life (QoL). Alongside, antimicrobial, anti-inflammatory, neuroprotective, regenerative, immunomodulatory, cardio-pulmonary health promotive, and psychological benefits of yogic and Ayurvedic intervention are well documented. Therefore, this study aimed to assess the effect of online Yoga (OYI) and Yoga cum Ayurveda intervention (OYAI) on COVID-19-induced depression, anxiety, PTSD, and poor QoL.

Method

Seventy-two participants (males/females: 33/26) with at least a 3-month back history of symptomatic COVID-19 infection and age (mean ± SD: 32.33 ± 9.9 and 33.04 ± 12.9 for males and females, respectively) were recruited from Patanjali Ayurveda Hospital, Haridwar, India, and All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India, before random allocation into an equal-sized control group (CG), Yoga group (YG) and Yoga cum concoction (YCG) group. Split-plot analysis of variance and Kruskal–Wallis tests with Bonferroni adjusted post hoc comparisons were computed for normal and nonnormal data using IBM SPSS (25th Version, SPSS South Asia Private Limited, Bangalore, India).

Results

Both the treatments—the 30-day OYI and OYAI, significantly improved depression ( P < .002, ES: -0.99 and P < .001, ES: -2.11), anxiety ( P < .001, ES: -1.32 and -1.89), PTSD ( P < .001, ES: -1.8 and -1.83) and QoL related constructs ( P < .001, ES: 0.63 and 0.76; 0.71 and 0.93 for each OYI and OYAI versus general health and physical health; P < .001, ES: 0.65 for OYAI versus psychological health; and P < .003, ES: 0.54 for OYI versus environment) of the participants compared to the controls.

Conclusion

OYAI may better ameliorate COVID-19-induced psychological comorbidities than OYI with no adverse effects.

Effects of Hatha yoga on cognitive functions in the elderly: a cross-sectional study

This study aimed to investigate the effects of Hatha yoga practice on cognitive functions in the elderly. Thirty healthy older men participated in this study. They belonged to 2 groups. The first group included 15 Hatha yoga practitioners for at least 2 years. The control group involved 15 male older adults who shared the same characteristics (age, years of formal education, and level of physical activity) as the Hatha yoga group but were naive to yoga, meditation, or any mind-body intervention. Neuropsychological tests were applied to measure selective attention, sustained attention, episodic memory, and processing speed. The following tests were administered: The French adaptation of the Victoria Stroop test, the Zazzo's Cancellation Task, the Five Word Test, and a battery of computerized tests to evaluate reaction time. Long-term Hatha yoga practice showed promising results related to executive functions and reaction time, but no significant difference was found between the two groups in episodic memory and sustained attention although a trend of improvement was observed in favor of Hatha yoga practitioners. In conclusion, long-term Hatha yoga practitioners have better cognitive abilities compared to the control group in certain aspects of cognitive functions. Further physiological and psychological variables need to be examined in order to highlight the correlation between yoga intervention and cognitive performance.

EEG signatures change during unilateral Yogi nasal breathing

Airflow through the left-and-right nostrils is said to be entrained by an endogenous nasal cycle paced by both poles of the hypothalamus. Yogic practices suggest, and scientific evidence demonstrates, that right-nostril breathing is involved with relatively higher sympathetic activity (arousal states), while left-nostril breathing is associated with a relatively more parasympathetic activity (stress alleviating state). The objective of this study was to further explore this laterality by controlling nasal airflow and observing patterns of cortical activity through encephalographic (EEG) recordings. Thirty subjects participated in this crossover study. The experimental session consisted of a resting phase (baseline), then a period of unilateral nostril breathing (UNB) using the dominant nasal airway, followed by UNB using the non-dominant nasal airway. A 64-channel EEG was recorded throughout the whole session. The effects of nostril-dominance, and nostril-lateralization were assessed using the power spectral density of the neural activity. The differences in power-spectra and source localization were calculated between EEG recorded during UNB and baseline for delta, theta, alpha, beta and gamma bands. Cluster-based permutation tests showed that compared to baseline, EEG spectral power was significantly (1) decreased in all frequency bands for non-dominant nostril UNB, (2) decreased in alpha, beta and gamma bands for dominant nostril UNB, (3) decreased in all bands for left nostril UNB, and (4) decreased in all bands except delta for right nostril UNB. The beta band showed the most widely distributed changes across the scalp. our source localisation results show that breathing with the dominant nostril breathing increases EEG power in the left inferior frontal (alpha band) and left parietal lobule (beta band), whereas non-dominant nostril breathing is related to more diffuse and bilateral effects in posterior areas of the brain.These preliminary findings may stimulate further research in the area, with potential applications to tailored treatment of brain disorders associated with disruption of sympathetic and parasympathetic activity.

Yogic Pranayama and Diaphragmatic Breathing: Adjunct Therapy for Intraocular Pressure in Patients With Primary Open-angle Glaucoma: A Randomized Controlled Trial

PRCIS

Yogic pranayama and diaphragmatic breathing are potential adjunctive therapies for patients with glaucoma; however, they are not substitutes for medicine or eye drops.

PURPOSE

Currently, medical or surgical lowering of intraocular pressure is the only therapeutic approach for treating primary open-angle glaucoma. Intraocular pressure maintenance is influenced by autonomic activity (sympathetic and parasympathetic). "Yogic pranayama" and "diaphragmatic breathing" are exercises that can affect autonomic activity by stimulating a wakeful hypometabolic state of parasympathetic dominance. We aimed to assess the effect of yogic pranayama and diaphragmatic breathing on intraocular pressure to determine whether it can be recommended for individuals with established glaucoma in combination with glaucoma medication as an adjuvant therapy.

MATERIALS AND METHODS

In this prospective, randomized trial, 90 patients with primary open-angle glaucoma (180 eyes, age: above 40 y) were assigned to either the control or yogic pranayama and diaphragmatic breathing exercise group. In the latter group, yogic pranayama and diaphragmatic breathing were practiced daily for 6 months. We measured the intraocular pressure at presentation and subsequently after 1, 3, and 6 months.

RESULTS

Compared with the wait-list group, the yogic pranayama and diaphragmatic breathing exercise group had significantly lowered intraocular pressure (right eye: 20.85±3.39 to 14.90±2.86 mm Hg; left eye: 20.30±4.12 to 14.25±3.85 mm Hg; P<0.001).

CONCLUSION

Yogic pranayama and diaphragmatic breathing exercises can reduce intraocular pressure in patients with primary open-angle glaucoma and can therefore be recommended as an adjuvant therapy.

Effect of Nasal Dominance on Pulmonary Function Test and Heart Rate: A Pilot Study

Background:

The nasal cycle is one of the many cyclic events in a human being. Nasal airflow is greater in one nostril at any given point in time and this alternates between right and left nostrils over time. Its periodicity ranges from 25 min to 8 h. This alteration has been known to be controlled by the autonomic nervous system. The current study was designed to assess the effect of nasal dominance during rest on pulmonary function parameters and heart rate.

Materials and Methods:

A cross-sectional study was done on 35 apparently healthy individuals of the age group of 18–30 years. Based on a cold mirror test, the participants were categorized into two groups of right nasal dominance (RND) and left nasal dominance (LND). The parameters recorded were forced expiratory volume in the first sec (FEV₁), forced vital capacity (FVC), FEV₁/FVC, peak expiratory flow rate, forced expiratory flow between 25%-75%, SpO₂, and pulse rate. Data were expressed as mean ± standard deviation and were analyzed using SPSS version 20.

Results:

All pulmonary function parameters exhibited higher values in RND participants compared to LND participants and the difference was found to be statistically significant (P < 0.05).

Conclusion:

Nasal dominance has a measurable effect on pulmonary functions and heart rate hence emphasizing the role of autonomic control of airways. This influence can be used as adjuvant therapy for certain disorders.

Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder

Approximately 45 million people worldwide are diagnosed with bipolar disorder (BD). While there are many known risk factors and models of the pathologic processes influencing BD, the exact neurologic underpinnings of BD are unknown. We attempt to integrate the existing literature and create a unifying hypothesis regarding the pathophysiology of BD with the hope that a concrete model may potentially facilitate more specific diagnosis, prevention, and treatment of BD in the future. We hypothesize that dysfunctional signaling from the parvocellular neurons of the paraventricular hypothalamic nucleus (PVN) results in the clinical presentation of BD. Functional damage to this nucleus and its signaling pathways may be mediated by myriad factors (e.g. immune dysregulation and auto-immune processes, polygenetic variation, dysfunctional interhemispheric connections, and impaired or overactivated hypothalamic axes) which could help explain the wide variety of clinical presentations along the BD spectrum. The neurons of the PVN regulate ultradian rhythms, which are observed in cyclic variations in healthy individuals, and mediate changes in functional hemispheric lateralization. Theoretically, dysfunctional PVN signaling results in prolonged functional hemispheric dominance. In this model, prolonged right hemispheric dominance leads to depressive symptoms, whereas left hemispheric dominance correlated to the clinical picture of mania. Subsequently, physiologic processes that increase signaling through the PVN (hypothalamic-pituitaryadrenal axis, hypothalamic- pituitary-gonadal axis, and hypothalamic-pituitary-thyroid axis activity, suprachiasmatic nucleus pathways) as well as, neuro-endocrine induced excito-toxicity, auto-immune and inflammatory flairs may induce mood episodes in susceptible individuals. Potentially, ultradian rhythms slowing with age, in combination with changes in hypothalamic axes and maturation of neural circuitry, accounts for BD clinically presenting more frequently in young adulthood than later in life.

The Effects of Fast and Slow Yoga Breathing on Cerebral and Central Hemodynamics

BACKGROUND

Yoga breathing has shown to impose significant cardiovascular and psychological health benefits.

OBJECTIVE

The mechanism (s) responsible for these health benefits remain unclear. The aim of the present study was to assess the differences in cerebral and central hemodynamic responses following fast breathing (FB) and slow breathing (SB) protocols compared to breathing awareness (BA) as a control.

METHODS

Twenty healthy participants (10 males and 10 females) volunteered to take part in the study. Participants were between ages 18-55 years (group mean: 24 ± 5 years), with a height of 168.7 ± 9.8 cm and a weight of 70.16 ± 10.9 kg. A familiarization trial including FB and SB protocols were performed by each participant at least 24 h before the testing day. The breathing protocols were designed to achieve 6 breath/min for SB and ~ 120 breaths/min for FB.

RESULTS

FB resulted in an increase in both right prefrontal cortex (RPFC) and left prefrontal cortex (LPFC) hemoglobin difference (Hbdiff) (brain oxygenation) compared to BA (P < 0.05). FB resulted in an increased Hbdiff in LPFC compared to RPFC SB (P < 0.05). FB resulted in an increased Hbdiff in LPFC compared to SB (P < 0.05).

CONCLUSION

FB may be an effective yoga breathing technique for eliciting cerebral brain oxygenation indicated by increased Hbdiff. These results may be applicable to both healthy and clinical populations.

Mindfulness and hemodynamics in asians: a literature review

INTRODUCTION

Mindfulness interventions have been increasingly incorporated into clinical settings. Evidence supporting mindfulness practices are predominantly established in Western populations. Neurophysiological evidence has not been established to support the effectiveness of mindfulness practice in Asian populations. Greater understanding of the neurophysiological mechanisms underlying mindfulness would enable hemodynamics as measured by fNIRS to be used to monitor mindfulness practice as an adjunct to psychotherapy with Asian clients.

METHOD

Research relating to fNIRS and hemodynamics for mindfulness in Asians was reviewed. The inclusion criteria for this review were recent publications in peer-reviewed journals from 2008 to 2018, with the search terms 'fNIRS', 'hemodynamics' and 'mindfulness', for studies in Asia.

FINDINGS

Databases included Medline, PubMed, PSYCINFO, Google Scholar and SCOPUS. Initial searches yielded 86 results. Five duplicated articles were removed, and remaining abstracts were screened; and assessed for eligibility against the structured performa. Three full text papers which fit the inclusion criteria were included in the current review.

CONCLUSION

This review highlighted the paucity of rigorous empirically validated research for hemodynamics as measured with fNIRS for mindfulness practice in Asia.

WearLight: Toward a Wearable, Configurable Functional NIR Spectroscopy System for Noninvasive Neuroimaging

Functional near-infrared spectroscopy (fNIRS) has emerged as an effective brain monitoring technique to measure the hemodynamic response of the cortical surface. Its wide popularity and adoption in recent time attribute to its portability, ease of use, and flexibility in multimodal studies involving electroencephalography. While fNIRS is still emerging on various fronts including hardware, software, algorithm, and applications, it still requires overcoming several scientific challenges associated with brain monitoring in naturalistic environments where the human participants are allowed to move and required to perform various tasks stimulating brain behaviors. In response to these challenges and demands, we have developed a wearable fNIRS system, WearLight that was built upon an Internet-of-Things embedded architecture for onboard intelligence, configurability, and data transmission. In addition, we have pursued detailed research and comparative analysis on the design of the optodes encapsulating an near-infrared light source and a detector into 3-D printed material. We performed rigorous experimental studies on human participants to test reliability, signal-to-noise ratio, and configurability. Most importantly, we observed that WearLight has a capacity to measure hemodynamic responses in various setups including arterial occlusion on the forearm and frontal lobe brain activity during breathing exercises in a naturalistic environment. Our promising experimental results provide an evidence of preliminary clinical validation of WearLight. This encourages us to move toward intensive studies involving brain monitoring.

Greater Cortical Thickness in Elderly Female Yoga Practitioners-A Cross-Sectional Study

Yoga, a mind-body activity that requires attentional engagement, has been associated with positive changes in brain structure and function, especially in areas related to awareness, attention, executive functions and memory. Normal aging, on the other hand, has also been associated with structural and functional brain changes, but these generally involve decreased cognitive functions. The aim of this cross-sectional study was to compare brain cortical thickness (CT) in elderly yoga practitioners and a group of age-matched healthy non-practitioners. We tested 21 older women who had practiced hatha yoga for at least 8 years and 21 women naive to yoga, meditation or any mind-body interventions who were matched to the first group in age, years of formal education and physical activity level. A T1-weighted MPRAGE sequence was acquired for each participant. Yoga practitioners showed significantly greater CT in a left prefrontal lobe cluster, which included portions of the lateral middle frontal gyrus, anterior superior frontal gyrus and dorsal superior frontal gyrus. We found greater CT in the left prefrontal cortex of healthy elderly women who trained yoga for a minimum of 8 years compared with women in the control group.