Yoga and the Brain

In recent years, largely due to growing sophistication of scientific and technological advances in the area of neuroimaging technology, there are a growing number of studies related to yoga and its positive effects on the brain. While in the past, yoga practitioners could only feel the difference, now science has reached a stage where we can qualitatively and quantitatively measure the difference. Studies in neuroscience is corroborating what yoga teachers and practitioners have known for ages—that yoga and meditation can literally change your brain. Neuroplasticity, or the brain’s ability to reshape itself, has been scientifically documented to occur, specifically for those having a regular yoga practice.

One study conducted using Magnetic Resonance Imaging (MRI) has shown that yoga affects different areas of the brain, including the somatosensory cortex (area which contains a mental map of the body), the superior parietal cortex (area involved in directing attention) and the visual cortex (area involved in sight). In addition to more gray matter, these areas were also found to be enlarged in regular yoga practitioners as compared to those who did not regularly practice yoga. The hippocampus (part of the brain critical to lowering stress levels) as well as the precuneus and the posterior cingulate cortex (areas involved in the concept of “self”) were all also found to be enlarged in practitioners.

Cognitive ability was also found to be improved in one study where subjects were tasked to participate in a 20-minute yoga session before performing a test. The results were compared to their own performance after 20-minutes of aerobic exercise, and a control of no activity. The hypothesis from this study is that there appears to be at least two mechanisms by which the practice of yoga improves cognitive ability, through improvement in mood (as lowered mood is associated with declines in cognitive function) and increased body awareness thereby improving general attentional abilities.

In another study, yoga was found to reduce anxiety and allay symptoms of depression. Research on the neurochemistry of yoga sheds light on this – Randomised controlled Magnetic Resonance Spectroscopy studies conducted demonstrate that the regular practice of yoga releases a chemical called GABA in the thalamus, as compared to walking. GABA plays a central role in suppressing neural activity, bringing feelings of relaxation and decreased anxiety, and was shown to be significantly higher in the brains of subjects who had been doing yoga. The study also compared GABA levels directly before and after an hour of yoga, where it showed a 27% increase. These findings suggest that yoga signals to the brain to release calming chemicals, the effects of which are felt in the hours following a session of yoga. As connections in the brain change their strength and configuration, the GABA released over a period of regular yoga practice can help boost baseline levels, helping  the brain rewire itself to have a calmer, less anxious response in the face of everyday stressors.

The above are just three studies out of a myriad being done to scientifically prove the effects of yoga. For most of us, we don’t need these studies to prove what we already know –  the calming, invigorating effects post-yoga speak for itself! 🙂

 

Josephine Goh

200hr TTC Jan-May Weekend