How God Changes Your Brain - Andrew Newberg, M. D_ [27]
We would argue that the more you meditate on a specific object—be it God, or peace, or financial success—the more active your thalamus becomes, until it reaches a point of stimulation where it perceives thoughts in the same way that other sensations are perceived. And if you exercise an idea over and over, your brain will begin to respond as though the idea was a real object in the world. This, we believe, is what may cause thalamic asymmetry in advanced meditators. Thus, the more you focus on God, the more God will be sensed as real. But it will not be a “symmetrical” reality. Instead, it will be perceived “asymmetrically,” meaning that the reality will appear different from one's normal perception of the world. For advanced meditators, the asymmetric reality becomes their normal state of awareness. God, tranquility, and unity become an integral part of their lives, no longer a thought but a palpable experience, as real as the book you are holding in your hand.
The thalamus makes no distinction between inner and outer realities, and thus any idea, if contemplated long enough, will take on a semblance of reality. Your belief becomes neurologically real, and your brain will respond accordingly. But for someone else, who has meditated on a different set of beliefs or goals, a different reality will seem true.
THE CHEMICAL NATURE OF GOD
Spiritual practices also have an effect upon your neurotransmitters, the chemicals that make your brain and body work. For example, a 65 percent increase in dopamine was found when individuals practiced yoga nidra,27 a form of meditation in which a person maintains conscious awareness while remaining in a state of complete relaxation. Dopamine heightens sensory imagery, generates pleasurable experiences, stimulates positive thoughts, increases your sense of well-being, and allows you to feel safe in the world. Even the high that results from cocaine is related directly to the sudden increase of dopamine in the brain. This may explain why some people equate spiritual experiences with drug experiences, since both share common pathways in the brain.
Indeed, the ability to believe in spiritual realms may be dependent upon the amount of dopamine that is released in the frontal lobes, and too little dopamine may bias a person toward skepticism and disbelief. On the other hand, high levels of dopamine may bias a person to foster paranormal beliefs.28 Other research has suggested that the balance of activity between the brain's left and right hemispheres could regulate a person's predisposition to spirituality or atheism.29
During intense forms of meditation (mindfulness, vipassana, insight, and Transcendental Meditation), serotonin levels in the blood are altered. In some studies it increases, in others it decreases, and many question whether the effects are beneficial or harmful.30 Some argue that meditation evokes small epileptic-like seizures, but to my knowledge not a single case of epilepsy has ever been directly tied to spiritual practices. There is, however, anecdotal evidence that people with unstable personalities could have their symptoms temporarily increased. But since there has been such widespread use of meditation in psychotherapy—where it has been proven to be especially effective in the treatment of severe depression—the evidence shows that it is a very effective treatment for mood disorders.31 The serotonin released during meditation may also be responsible for the enhanced visual imagery and sensory experiences often reported during intense spiritual practice.
Research has shown that spiritual practices affect other important neurochemicals in the brain. For example, gentle forms of yoga that involve breathing