Let's switch gears and talk about the effect of meditation on your emotions. Remember, your emotions are mainly from your amygdala and your insular cortex.
The amygdala is your alarm system. And where all your fears are housed. The insular cortex is where your emotions are interpreted.
Most meditation research has focused on practices that emphasize calming the mind, improving focused attention, or developing mindfulness. Most recently, neuroscience research has turned to compassion and loving kindness meditation. In loving kindness compassion meditation, expert practitioners compared to novices, show more, not less, emotional reactivity to sounds of people in distress. Faster heartbeat and stronger response in the insular, which is linked to introspection and empathy, which cannot be explained by the relaxation response hypothesis.
As for meditation in the immune system, a small study was done by Davidson et al, observing the effect of an eight week mindfulness-based stress reduction training, compared to subjects who did not get the training. They looked at the prefrontal cortex activation patterns, the left prefrontal cortex being associated with positive emotions and approach-oriented behavior. While the right is associated with negative emotions and avoidance-oriented behavior. The group who received the training had more activation of the left prefrontal, cortex which is associated with positive emotions.
How does that translate in the immune system function? The immune system function is measured through the amount of certain antibodies in the blood. In the Davidson et al study the immune system improved with meditation. There was also a correlation between the amount of antibodies and the amount of left prefrontal cortex activation. Meaning, the better you got at meditating, the better your left prefrontal cortex activation and the better your immune system response. That is an amazing dose response.