The Neuroscience of Yoga: Bridging the Gap Between Spirituality and Science

Yoga has become increasingly popular in the last decades and anyone who has attended a handful of yoga classes would agree to feeling an increased sense of emotional stability and mental clarity after practice. Nowadays, thanks to sophisticated brain imaging techniques, neuroscience is revealing exciting and transformative insights about the art and science of yoga. Western science is finally confirming what eastern practitioners have been reporting and documenting for over 2,000 years: that yoga and meditation can literally rewire the structure of the brain. 

What Is Yoga, Anyway?

Yoga (from Sanskrit meaning “unity”) is an ancient practice that unites the innate capacity of human beings to realize their true potential. We recognize our highest potential through the practices of the various yoga disciplines, such as yoga asana or physical postures, breathing regulation, meditation, study of teachings, devotional chanting, among others. In the West, we became familiarized with yoga asana, which only represents one aspect that the practice uses to align us with our highest potential and develop higher qualities, such as more love, compassion, humbleness, kindness, empathy, insight and service.

In the early 2000s, Richard Davidson from the University of Wisconsin jump-started the convergence of both worlds with his famous research on meditating Buddhist monks, finding mental training in form of meditation may induce short and long-term neural changes in the brain [1]. Several other researchers have followed, including Sarah Lazar, who found that brain regions associated with attention and sensory processing were thicker in people practicing meditation. The changes were observed even in novice meditators with as little as two weeks experience. This means that not only meditation professionals benefit from the practice [2]. 

Sharpening Higher Cognitive Functions

In as little as 15 years, the emerging field has witnessed almost a 10-fold increase in published research papers on the impact of yoga in human health [3]. Several papers focus on the pre-frontal cortex and the attentional engagement that yoga requires. Positive changes in the brain structure and function of areas related to awareness, decision-making, executive functions, self-regulation and attention have been observed [4], leading to an efficient regulation of emotions, social behavior, impulsivity, fears and conflicting thoughts. This area is also strongly implicated in human qualities such as empathy, consciousness, social and emotional intelligence, insight, intuition and attuned communication [5]. One of the most interesting studies in this area found that 50 year-old meditators had similar cortical thickness as 25 year-olds, suggesting that yoga might offset age-related cortical thinning [2] .

via Flickr by Amila Tennakoon

Nowadays, one of the most prevalent health threats is stress. Everybody has experienced it in one way or another. Long-term stress can have significant adverse effects on health and is a risk factor for many major illnesses, such as heart disease, stroke and depression [6]. Neurobiological studies have implicated the amygdala as a crucial area involved in our stress response. A recent study found that participants following an 8-week yoga intervention reported significantly reduced perceived stress and a reduction in the right basolateral amygdala gray matter density [7], furthering our understanding of why we feel so good during and after a yoga class. 

Breathing Into Your Memory Center

The hippocampus plays a vital role in long-term memory, learning, navigation and spatial orientation. Recent studies have found an increased hippocampal volume in elderly participants over a period of 6-months, suggesting that yoga could have the potential to alleviate age-related neurosenescence, findings of particular importance for the field of neurodegenerative diseases, such as Alzheimer’s disease [8]. Furthermore, depression is a potential risk factor for cognitive decline and dementia and recent reviews suggest that a yoga intervention might effectively reduce these symptoms [9].  

I think everyone who has taken a yoga class can relate to the unique experience that this practice brings to one’s day. Our mind can be in an absolute turmoil when getting to class, thinking about the next deadline, the shopping list, answering our boss's email, and so on, but then we feel absolute peace when lying down in savasana, the final resting posture. Yoga has been shown to restore the autonomic nervous system to a healthy balance by stimulating the parasympathetic nervous system. It reduces our heart rate and blood pressure, eases our respiration and increases heart rate variability – all signs of improved parasympathetic tone and a peaceful smiling face after class [10].

Yoga might offset age-related cortical thinning

 

A number of published papers conclude that breathing, meditation, and posture-based yoga increases overall brain health and yoga practice may be an effective treatment for a clinical and healthy aging population, in addition to being relatively easy and cost-effective to implement [11]. So now, if you have not yet experienced a yoga class, I invite you to attend one and feel for yourself all the benefits this millennial practice has to offer. After a while, yoga becomes not what we do, but rather how we do something. When we invite an ever-present awareness to all that we do, yoga becomes a way of living, rather than just a disciplined practice we commit to one hour a day.

by Stephanie Bianchi, MSc in Neuroscience / Mindful Guatemala

This article originally appeared September 2017 in CNS Volume 10, Issue 3, Spirituality in Science

 
[1] Lutz et al., Proc Natl Acad Sci, 2014
[2] Lazar et al,. Neuroreport., 2005
[3] https://www.ncbi.nlm.nih.gov/pubmed/?term=yoga
[4] Afonso et al., Front Aging Neurosci., 2017
[5] Desai, Effects of Yoga Nidra and other Meditation Techniques, In: Yoga Nidra: The Art of Transformational Sleep, 2017
[6] Tawakol et al., The Lancet, 2017
[7] Hölzel et al., Soc Cogn Affect Neurosci., 2010
[8] Hariprasad et al., Indian J Psychiatry, 2013
[9] Mathersul et al., Evid Based Complement Alternat Med., 2016
[10] Stephens, Children (Basel)., 2017
[11] Desai et al., Complement Ther Clin Pract., 2015

On Mind, (White) Matter and Meditation

In our modern times, everyone rushes between appointments, fulfills work-related tasks all day and is busy with several means of self-optimization. In a bid to find their inner center again and rest, people are increasingly turning to centuries-old traditions like yoga and meditation.

Meditation is a concept from several Asian spiritual traditions where one’s attention is focused on a single thing such as breathing, bodily sensations or certain words or phrases known as “mantras”. For example, an easy approach is progressive muscle relaxation, where you consecutively contract and then relax different muscle groups to focus on that particular sensation. In principle, meditation means turning away from distractions of any form and concentrating on the present moment. While it sounds relatively simple, it is not easy to escape outer and inner noise. To those wondering whether they meditate correctly, there is an easy way of checking: "if you are feeling better at the end, you are probably doing it right." [1]. Another aspect of meditative practice (which appears very Buddhist in its own right) is that there is no right way to meditate because there is no goal to reach. Instead, the journey is the real aim [2]. And just like physical exercise, you will perform better with practice.

There Are Many Paths to Meditation
What actually happens during meditation that drives Homo economicus to adopt centuries-old traditions to calm down? For several decades, science has been trying to elucidate the psychological and physiological mechanisms behind mindfulness and meditation. Unfortunately, despite increasing popularity in research, this particular field of study faces severe methodological problems: there is an immense degree of individual variety among the general background of neuro-connectivity, meditation practice, and expertise of the subjects. As a consequence, and even though researchers readily make use of EEG, fMRI, PET and other sophisticated neuroimaging techniques, results are often inconclusive.

source: http://bit.ly/2uWg0dA

One of the earliest studies reported a decrease in blood pressure of hypertensive patients following meditation [3]. EEG studies showed a reduced frequency of alpha and theta waves linked to meditative state [4]. Depending on the type and tradition, meditation may lead to different effects. For example, researchers found increasing sympathetic activity and arousal with practice of Hindu tantric meditation as opposed to heightened parasympathetic activity and calmness when following other traditions [5]. Network connectivity studies with expert Taoist meditators reported significant differences in brain white matter and functional network topology between resting state and during meditation [6], while others find activation of basal ganglia (caudate body), limbic system (entorhinal cortex) and medial prefrontal cortex (MPFC) [7].

Meditation focuses on the moment

Changes in brain activity and/or connectivity may also underlie the beneficial effect of meditation and mindfulness on pain. Pain consists of two elements: the sensory perception and the cognitive evaluation of this perception as painful. A review discussed the changes in brain activity with meditation practice as a consequence of increased thalamus and insula activity (where the sensation itself is processed) and a reduction in MPFC activity (responsible for the evaluation of pain). Therefore, it seems that meditation and mindfulness are effective because they alter the way sensory perception is assessed [8], a concept which may be applicable to a variety of health and mental problems.

Meditation to Improve Mental Health?
Recently, a large review took a deeper look at these topics [9]. Of all evaluated 18,000 citations, only 47 studies showed satisfactory methodological quality and could be included. From these, the authors conclude that meditation is likely not superior to active treatments (e.g. psychotherapy or medication) regarding stress-related problems, such as anxiety, depression and pain, yet a legitimate alternative in terms of side effects. One of the best accepted effects of meditation and mindfulness is stress reduction. It is not surprising, therefore, that big tech companies have started using these practices as a general leadership strategy to increase creativity and productivity [10].
What about you? Have you got experience with stress or ever lost your head over endless to-do-lists and half-baked could-be-done ideas? Maybe it is your turn to take your time and shape up your brain connections in order to be more creative, focused and happy!

by Bettina Schmerl, PhD Student AG Shoichet

This article  originally appeared September 2017 in CNS Volume 10, Issue 3, Spirituality in Science

[1] http://bit.ly/1CfRBPx
[2] http://bit.ly/29s6NAn
[3] Benson et al., J Chronic Dis. 1974
[4] Cahn and Polich. Psychol Bull. 2006
[5] Amihai and Kozhevnikov. Biomed Res Int. 2015
[6] Jao et al., Brain Connectivity. 2016
[7] Sperduti et al., Conscious Cogn. 2012
[8] Zeidan and Vago, Ann Y Acad Sci, 2017
[9] Goyal et al., JAMA Intern Med. 2014
[10] http://bit.ly/1TmWHgu

Spiritual Experience and the Default Mode Network

Ecstasy, awe, peace, the experience of the insight that "all is One", a sense of being "outside of time", the feeling that you experienced something sacred and holy, a gain of insightful knowledge experienced at an intuitive level…Trippy, right? Well, these are all elements from the Revised 30-item Mystical Experience Questionnaire [1] that is based on the seven dimensions of mystical experience, described by the British philosopher Walter Stace in 1960 [2]. This questionnaire has been used in the study of mystical experiences elicited by psychotropic drugs, like psilocybin and LSD (see article on page 6).

A Sufi in Ecstasy in a Landscap, source: Wikimedia Commons

Ceremonial use of hallucinogenic drugs dates back many thousands of years and is still part of many indigenous cultures of America (see also page 7). Although the reasons for using these substances in the ceremonies are varied, the goal is usually to facilitate the occurrence of a spiritual experience. Mystical or spiritual experiences occur also in the absence of drugs and have been reported inside and outside religious contexts. Meditation practices (page 5), for example, can lead to the experience of unity or pure awareness. For that reason, psychotropic drugs and meditative states have been used as models to study the neural correlates of mystical experience.

What Is the Default Mode Network?
Changes in the activity and connectivity of the default mode network (DMN) have been identified in studies where psychotropic drugs were used to elicit mystical experiences. This same network also shows changes during different meditation practices [3]. The default network is pretty much like the screen-saver of your brain. It is the network that gets active when you are not engaging in any activity that requires external focus, but rather just resting and letting your mind wander. The main components of the DMN are the medial prefrontal cortex (mPFC), the posterior cingulate cortex (PCC), the parahippocampal cortex (PHC) and the inferior parietal lobule (IPL) [4]. All these areas have a high density of serotonin 5-HT receptors, which are the targets of psychotropic drugs.

How attached are you to your ego?

What is interesting about this network is that it appears to be involved in the perception of self. Since it integrates information from different areas of the brain, it appears to be giving a constant update on self-awareness. The PHC, for example, stores episodic memory [5], while the mPFC and PCC overlap with social cognition and self-referential areas of the brain [6]. These areas are active when you are entertained in your own internal dialog, thinking about yourself or other people’s thoughts and intentions. The IPL, on the other hand, has been implicated in the processing of time perception [7]. Brain imaging studies using psilocybin, LSD or mescaline, as well as studies that looked at the brain of experienced meditators, found both a decreased activity and decreased connectivity of the DMN. Therefore, it is hypothesized that a decrease in the connectivity of the IPL with the rest of the DMN mediate the feeling of timelessness and spacelessness, while the decreased connectivity in the PCC and mPFC mediate the feelings of unity and ego dissolution [3].

On Cloud Nine?
It is always exciting when common neural correlates can be found for such a broad and subjective human phenomenon like the spiritual experience. However, the mystery of mystical experiences still remains. It is interesting, for example, that these transient experiences of ego dissolution come with long- (often life-long) lasting feelings of insight and positive behavioral changes. How can a momentary detachment from our persistent self-awareness give us the feeling of an encounter with an ultimate truth?

Spiritual Yoga, source: pixabay

Interestingly, the salvation or liberation from the self is a recurrent idea in many religions. To become part of the Absolute, reach Nirvana or be in God’s glory is the ultimate goal of the major religions of the world. Religious/spiritual practices aim to achieve this state through self-transformation and self-renunciation. Certain attitudes like the distancing from practical life and detachment from one’s and others’ needs and affections can facilitate the emergence of spiritual experiences [8]. What about you? Have you been close to a mystical experience?

[1] Barrett et al, J Psychopharmacol, 2015
[2] Stace, McMillan Press NY, 1960
[3] Barrett and Griffiths, Curr Topics Behav Neurosci, 2017
[4] Fox et al, PNAS, 2005
[5] Ranganath and Ritchey, Nat Rev Neurosci, 2012
[6] Shilbach et al, Conscious Cogn, 2008
[7] Battelli et al, Trends Cogn Sci, 2007
[8] Steinbock, Indiana University Press, 2007


by Silvina Romero Suárez,  PhD Student AG Infante

This article originally appeared September 2017 in CNS Volume 10, Issue 3, Spirituality in Science

New Issue Out Now! SPIRITUALITY IN SCIENCE

Is spirituality a topic that neuroscience should shun? We don’t think so! That’s why the September issue of the CNS newsletter is taking a closer look. 

click here to read

Besides exploring what religiosity looks like in your brain (pages 3 and 13), we invite you on a journey through the world of psychoactive drugs and plants (pages 6 and 7). But, as our frequent readers know, that’s not where we stop. We looked at what religion itself (page 11) and several “spiritual” practices can do for your mental (and physical) health, including fasting (page 14), meditation (page 5) and yoga (page 12). As a special treat for you, we also sat down with neuroscientists from Berlin to find out how they relate to faith (pages 8-9).
While some people struggle with bringing the spiritual and the worldly together in the workplace, we don't! In fact, this issue features one of the longest career sections in the history of our newsletter. We are excited to cover an interview with a neuroscientist-turned-yoga-teacher (pages 16-17), a recap of this year’s BioBusiness Summer School and annual Neurasmus meeting (page 18) and show you how to use activating teaching methods (page 19). And if you don’t agree with our take, we will even show you how to call BS (page 20).

Want to find out more? Stay tuned for the next postings!

Amen, Namaste, Salem Aleikum, Shalom and happy reading!

Helge Hasselmann Constance Holman
Co-editors-in-chief

This editorial originally appeared September 2017 in CNS Volume 10, Issue 3, Spirituality in Science