Sara Lazar is a neuroscientist at Massachusetts General Hospital and Harvard Medical School. Twenty years ago, she was a doctoral student in molecular biology. She suffered running injuries training for the Boston Marathon, and her physical therapist recommended stretching. Lazar started attending yoga class, where her teacher encouraged meditation. She was so impressed with the results that she did post-doctoral studies in neuroscience, and focused on the benefits of meditation. She was one of the first scientists to prove that meditation actually produces changes in the brain.
Her first study used long-term meditators as a control group. She found they had more gray matter in the insula and sensory areas, the auditory and sensory cortex. She attributes that to the fact people who meditate regularly pay attention to their breath, to sounds and to the present experience, temporarily shutting down cognition. She also found more gray matter in the frontal cortex, which governs working memory and decision making.
Dr Lazar says:
It’s well-documented that our cortex shrinks as we get older – it’s harder to figure things out and remember things. But in this one region of the prefrontal cortex, 50-year-old meditators had the same amount of gray matter as 25-year-olds.
So the first question was, well, maybe the people with more gray matter in the study had more gray matter before they started meditating. So we did a second study.
She and her team enlisted a group of subjects who had never meditated, and gave them an eight-week stress reduction course based on mindfulness. In that group, they found the brain had thickened in four regions. Lazar explains:
1. The primary difference, we found in the posterior cingulate, which is involved in mind wandering, and self relevance.
2. The left hippocampus, which assists in learning, cognition, memory and emotional regulation.
3. The temporo parietal junction, or TPJ, which is associated with perspective taking, empathy and compassion.
4. An area of the brain stem called the Pons, where a lot of regulatory neurotransmitters are produced.
The amygdala, the fight or flight part of the brain which is important for anxiety, fear and stress in general. That area got smaller in the group that went through the mindfulness-based stress reduction program.
The change happened in only eight weeks. The average time spent in meditation was 27 minutes daily. Some meditation teachers believe as little as 10 minutes a day can have an impact, although many people believe 40 minutes is optimal. Lazar says meditation is just like exercise, only exercise of the mind. It offers many of the same benefits, from increasing health to improving reactions to stress, to greater longevity.