In a recent study aptly titled, Neuroprotective Effects of Yoga Practice, the brains of experienced yoga practitioners were compared to those of non-practitioners with similar health profiles. Using magnetic resonance imaging (MRI), researchers at The National Center for Complementary and Integrative Health were able to identify regions of activity and growth. As a result, this study found that:
- A regular practice combining breath awareness, physical postures and meditation can increase the volume of gray matter (brain tissue) in different parts of the brain, effectively reducing the naturally occurring, age-related decline of brain cells. With most of the observed gray matter volume changes having occurred in the left-side of the brain, the implication is that yoga shifts the automatic response of the practitioner from fight-or-flight (right-brain, sympathetic nervous system activation resulting in acute physical stress) to rest-and-digest (left-brain, parasympathetic nervous system activation promoting calm and relaxation)
- The areas of the brain indicating the greatest change in gray matter were those directly related to sense of self, attention, spatial/sensory awareness as well as stress reduction. These findings provide a potential neural basis for the benefits of practicing yoga. The observed benefits were greater in those who practiced more often over a longer period of time supporting the notion that a consistent practice of yoga every day is more effective than an intermittent one
The Science of Sadhana: Positive Gene Expression
In 2013, studies at the University of Oslo offered a unique look inside the cellular structures of the human body to provide real, measurable data on what actually happens to cells when we practice yoga.
The Norwegian research team discovered that various yoga practices immediately impacted the expression of 111 genes, increasing the function of some while decreasing the function of others.
The Science of Sadhana: Increased Interoceptive Awareness
Norman Farb from the University of Toronto conducted a study on interoceptive and exteroceptive attention where he discovered key differences in the location of brain activity resulting from directed attention, either inward or outward.
What Farb encountered in his study was that when participants focused on an external screen (exteroceptive attention), the primary brain activity occurred in the neocortex, the most recent evolution in the human brain which differentiates us from other species and processes sensory information predominantly from external input. On the other hand, when participants were instructed to observe their breath (interoceptive attention), brain activity was heightened in the areas of the brain that bridge the cortex and the limbic system which is much older in terms of evolution, governing basic instincts and primal emotions.