Science of Yoga: Explorations in the Mind-Body Connection
It’s no secret that the physical body is connected to the mind and spirit. When we overtax our muscles and bones, we start to wear down much more than our prospects for long term health and overall life span. The body is a vessel for experience and the state of it directly determines our here and now. Much of modern life, including the advertisements that are embedded everywhere — from billboards to less conspicuous culprits, such as our friend’s snapshots of recent travels on social media — aims to convince us that our state of health is beyond our control and that decay — on the physical, mental, and spiritual planes — is, at worst, inevitable and, at best, something that we can stave off with temporary solutions. As time speeds away from us we realize that bandaids are unsatisfactory. But what if there was a more permanent solution in sight? Something that was guaranteed to put us back in control of this game of life?
Taking back your power starts with the singular journey that modern life aims to distract us from—this journey is the one inwards, towards the self. To make contact with the self takes work. Starting with the outer self makes sense; if we can’t exercise power and control over our bodies, how do we expect to do the same over more subtle matters like our states of mind and levels of satisfaction in life?
The Journey from Superficial to Subtle: The Mind Echoes the Physical Body
Often times, we think of our external realities as being reflective of the internal. While this pathway of thought is true, it does not represent the whole picture. There is a mind-body connection that goes both ways; the internal mimics the external and vice-versa. For that reason, it is understood that whether we make changes physically or mentally, we will see the results in both directions; that is, if we make changes outwardly, we will see changes inwardly, and if we make changes inwardly, we will make changes outwardly.
The mind-body connection is still mysterious. While it has been espoused as existing by philosophers for millennia, it is only just being 'confirmed' by helpful (if still narrow) areas of scientific research and expertise found in fields such as biochemistry and neuroscience. Yoga suggests that the practitioner first start making changes externally, or physically, rather than internally, or mentally. That's because physical changes are by-and-large easier to produce due to our shared human history of experience, which is dominated by physical markers.
Think of it; when we are stressed, grieving, or feeling any other sort of negative emotion, it's common to see a physical transformation: the body will flood with adrenaline and cortisol (the stress hormone) while the heart will quicken, the breath will become shallow, and so on. But how do we reverse the behavior—how do we calm ourselves down? The most common response, when coming to a friend while in distress, would be for the friend to say: "Breathe." And as we take deep breaths in and deep breaths out, we will notice the physical changes in reverse (that is, going from the more gross to the more subtle levels)—as our breathing becomes slower, steadier, fuller, our hearts, then our chemicals follow—and these physical changes inspire (or produce?) the desired state of mind: calmness instead of intense emotion. It is interesting that while our internal states often produce visible physical reactions, to reverse the process we control our physical reactions—we advise each other to "Breathe" instead of something more vague or subtle like "Tell your body to stop making cortisol" or "Stop thinking negative thoughts!"
Yoga keeps the ease of making physical changes in mind when prescribing a path to taking back control of one's mind and thereby, one's life. In the eight limbs of yoga, we are prescribed eight steps that should take us to this lofty goal of self-realization, of complete mind control. It is only the 6th, 7th, and 8th step that revolve around the subtler mental acts of one-pointed concentration, meditation, and samadhi (an inexplicable merging with the oneness that pervades all). The first 5 steps are conversely concerned with ethics, physical postures, control of life force (predominately via the route of breathing exercises), and sense withdrawal.
The Neuroscience Behind Yoga: How Pranayama, Breathwork; Asana, Steady Postures; and Dhyana, Meditation, Affect the Brain
Yoga is a lot of things; for the sake of the question "How does yoga impact the brain?" we will define yoga within its 3 predominant pillars of pranayama (control of the vital life force, often equated to breathwork); asana (the holding of steady postures); and dhyana (meditation and contemplation, which is informed by dharana, one-pointed concentration). So how does a regular practice of (in short) breathing, holding steady physical postures, and meditating affect our brains?
Here's what the science tells us about the positive benefits of yoga on brain connectivity:
- A review of 11 studies in the scientific journal Brain Plasticity found that yoga increased the size of...
- the hippocampus (the region of the brain known for memory processing that shrinks with age and is the first structure to be affected by dementia and Alzheimer's)
- the amygdala (the region of the brain responsible for emotional regulation and the stress response)
- the prefrontal cortex (a brain region found just behind the forehead and essential for planning, decision-making, multitasking, thinking about one's options and picking the right option)
- the cingulate cortex (part of the limbic system, it is a circuit of structures that play a key role in emotional regulation, learning, and memory)
- This review concluded that while yoga seems to cause many of the same changes as aerobic exercise, "yoga is not aerobic in nature, so there must be other mechanisms leading to these brain changes"
- Research has shown that regular yogic practices decrease the size of the amygdala, the part of the brain associated with emotional regulation, particularly fear, anxiety, and aggression. The loss of size (reflection in the loss of gray matter or neural cell body volume) results in less connections to the amygdala, which means there is decreased activity in that region of the brain. What does less activity in the amygdala look like? It manifests as higher rates of emotional control and response, especially to situations involving stress and threats.
- The increases in neurons in the pre-frontal cortex and the hippocampus results in: greater efficiency and skill in inhibiting negative behaviors and thoughts; self-regulation; and improvements in both spatial and working memory.
Here's what the science tells us about the positive benefits of yoga on brain chemistry:
- Research shows that yogis have an improved ability to manipulate a human's 'internal pharmacy', altering brain chemistry via the chemical changes, predominately in the levels of neurotransmitters (the signaling molecule the body uses to transmit messages between neurons). The chemical changes studied in yogis can be seen in the...
- increased levels of dopamine, oxytocin, and serotonin—the feel-good trio of hormones known to translate to joy, bonding, energy, and satisfaction
- higher levels of gamma-aminobutyric acid (GABA), a neurotransmitter that plays a key role in the down-regulation of our stress response
- reduction in norepinephrine, a neurotransmitter key to our sympathetic (fight or flight) nervous system, which correlates to improved management of fear and better overall heart health
- Many of the chemical responses studied in yogis directly affect our parasympathetic nervous system—also known as our 'rest and digest' system... this is internally restorative, rebalancing all of our systems
For Yoga to Change Your Brain, Commitment is Key
The benefits seen in the brains of yoga practitioners globally are within grasp for all of us—but they require consistency, commitment, and a mindset of discipline when it comes to our yogic practices. The amount of benefit you see will be directly influenced by your individual commitment to practicing yoga. BUT... once you make that commitment, the jury says that you won't regret: by increasing how often we activate our parasympathetic pathways, we improve circulation to our endocrine glands and digestive organs. That means that things like heart health, blood pressure, and breath rate can be managed more efficiently. Overall improvements in brain chemistry mean improvements in hormonal health... and hormonal health is responsible for the inflammation underlying most of our physical ailments as well as various decreases in cognitive function. So, spending time on the mat doesn't just make you look good on the outside... and makes you look good on the inside too, giving your body the time it needs to detoxify our internal organs and systems to eliminate that which is no longer serving us.