How God Changes Your Brain - Andrew Newberg, M. D_ [18]
Numerous studies have shown that the mere repetition of a sound, phrase, or finger movement over a period of time significantly reduces symptoms of stress, anxiety, depression, and anger, while improving the practitioner's perception of quality-of-life and spiritual well-being.37 In fact, the addition of movement to any meditation should significantly enhance the cognitive performance of the brain.38 Repeated, skilled finger movements also appear to improve the central and peripheral nervous systems, offsetting the age-related loss of hand control.39 In one study, musicians who used repeated finger movements had lower rates of dementia,40 and in another, early musical training with children resulted in the “long-term enhancement of visual-spatial, verbal, and mathematical performance.”41 In fact, it is fair to consider any musical training a form of cognitive meditation because it involves intense concentration, repetition of instructional techniques, body coordination, and motivational attention.
There is even considerable evidence documenting the effects of pleasant music on the brain. It deepens emotional experience,42 enhances visual and auditory processing,43 and improves attention and the processing of emotions.44 Thus, we recommend that you play some classical or melodic music in the background when you meditate or pray. And if you “sing” your mantra or prayer, as is done in the Kirtan Kriya tradition, you'll increase your cognitive performance.45
We also want to point out that there is considerable interplay between the brain mechanisms that regulate anxiety, stress, and memory.46 For example, high levels of stress lead to memory decline and increase the risk of developing Alzheimer's disease.47 Again, most of the meditations discussed in this book will trigger the body's relaxation response and thereby lower stress. And as most people know, stress is the number one killer in America because it damages nearly every organ in the body—especially your brain.
EXERCISING YOUR DENDRITES
Our current understanding of the human brain shows that subtle deterioration in any part of a neuron—in its coating, synapses, or the way it responds to neurochemicals—will impede cognitive function.48 But the real key to understanding cognitive enhancement and deterioration may lie in the microscopic dendrites that are on the receiving ends of neurons. In fact, they may even harbor the secret to why humans—and only humans—contemplate the nature of God.
A single neuron can have as many as ten thousand little tentaclelike branches that reach out toward the signaling ends of other neurons. Picture, if you will, the roots of a giant tree: These are the dendrites, collecting information and sending it up into the body of the neuron (the tree trunk), which then decides what other dendrites to stimulate through the axon terminals (the leaves) that grow out of the ends of one of the neuron's “branches.”
Mild, short-term, or chronic stress impairs memory by disrupting dendritic activity.49 Researchers working with rats (whose brain functions are remarkably similar to humans) found that it took only one week of mild stress to cause significant alterations in dendrite organization and growth.50 If the situation that is causing the stress is removed, function is restored.51 But not completely, for nearly one-third of the damaged dendrites were permanently lost if the stress was later repeated.52
Dendrite loss in the prefrontal cortex has also been found in aging humans.53 For example, we have known for decades that Alzheimer's patients suffer this kind of loss.54 However,