Yoga? Show me the research.
Research is important, but in terms of my personal yoga practice, I look at myself less as a scientist and more as a science experiment. If my back feels good, I’m sleeping better, my mood is steady, and I’m generally feeling responsive rather than reactive, then my experiment is valid. I don’t need a randomized clinical trial to convince me that yoga can do all these things, I have already conducted my own successful research.
However, since I’m a yoga teacher – I can’t assume my students have the same issues I do (projection belongs in movie theaters). Maybe some of the things I do will help them, but I also need to be able to access a more objective reality. For this, I can go in one of two directions – the tradition and what the gurus have said, or science and what the researchers have demonstrated.
And since this is a blog about neuroscience, you and I both know where I need to go. With all due respect (and much respect is due), here we’ll put the superlative claims about yoga in the parking lot and look at a summary of the research.
The researchers have nicely summarized the empirical evidence for how yoga promotes self-regulation and divided it into three categories: Cognitive, emotional and behavioral. Of course these three categories overlap each other in significant ways. Nevertheless, it’s a useful analysis.
1. Cognitive self-regulation essentially means accessing the processes of cognition and using them to bring the system (that is, you) to homeostasis. Executive function is the capacity of the front brain to keep you on task. Research has shown that yoga – especially pranayama – improves concentration. Yoga also benefits memory and concentration – which may be better than this alternative:
There’s also been some research demonstrating that yoga improves some of the cognitive decline associated with aging.
One juicy tidbit is that some studies “suggest increased integration between explicit and implicit processes that regulate cognitive and perceptual abilities.” This is especially important in terms of integrating and healing trauma. Traumatic experiences are often remembered in terrifying flashbacks and chaotic sensations. Yoga seems to be able to help people create narratives out of messy memories and thereby begin to heal. (Note: this is only one neurologic process through which yoga heals trauma, there are lots of other mechanisms at play).
2. Emotional self-regulation means the capacity to respond in a balanced way to various experiences and to delay spontaneous reactions. It’s basically about dealing with stressors. A few studies with college students have shown that yoga (as opposed to just plain exercise) increases self-compassion and non-judgmental self-reflection. Another study showed that yoga can help change physiology, so that you feel safer in your body and can respond in a balanced way even during threatening situations.
In emotional self-regulation, the front brain exerts control over limbic structures. I like to think of the front brain as your inner Spock. Your body is like the Starship Enterprise and Mr. Spock is sitting on the bridge doling out logical advice.
You have a fear of snakes but like to walk in the woods. A stick lies across your path, your right hippocampus remembers snake images and sounds the alarm. Your amygdala freak out and shouts: “Snake, snake!” at your brain stem which responds by kicking in your hypothalamic pituitary adrenal axis. This revs up your respiratory and heart rate, sends blood to your extremities, dilates your pupils and shuts down your digestion. But Mr. Spock overrides the reaction: “This is highly illogical.” and, from the bridge, turns off the red alert. Your system returns to homeostasis.
3. Behavioral self-regulation is the capacity to regulate your behavioral responses to stressors. It is related to our tendencies to fall into samskaric or habitual patterns to deal with stress. You may relate to this scenario – I’ve had a long day, I come home, flop on the couch with a pint of Coconut Bliss Mint Galactica, and watch Big Bang Theory. Not much behavioral self-regulation going on there (and frankly, it’s fine (and fun!) as long as it remains an intermittent strategy and I’m not using it as a primary coping technique.)
Research has shown that yoga may help decrease cravings (even with smoking!) and improve physical activity in the previously sedentary. The amount of yoga you do seems to be inversely related to the use of dysfunctional coping strategies. So more yoga equals less tuning out, venting, and substance use. Yoga improves mindfulness – which means you are more aware of your behaviors and therefore can do something to regulate them.
References for all these studies I’ve cited can be found in the article.
There is so much more that neuroscience is showing us about the benefits of yoga. And I’m working on a book about yoga and mental health, so if this whets your appetite, stay tuned!