Brainwaves

Nowhere do we see the rhythmic, cyclic pattern of the biocomputer’s activity so compellingly illustrated as in the electric signals coming from the brain. In about 1920, German physiologist Hans Berger demonstrated that electrodes attached to the scalp could detect the minute voltage differences between different areas of the brain and could monitor the voltage oscillations caused by the simultaneous firing of millions of neurons. He referred to his device as the electro- encephalograph. Researchers and physicians now use these “brainwaves” to study the brain’s operation and to diagnose and treat a wide range of neurological disorders. Neuroscientists have divided up the range of brainwave frequencies into a series of bands, much like musical notes on a scale. By adjusting their equipment to select only certain ranges of frequencies, they can see the relative proportion of energy that goes into each range. If one band of frequencies is getting much more energy than the others, researchers say that this particular band—or brainwave—is predominant at the moment, and they are able to associate the individual’s reported mental
state with the brainwave that’s most prominent. Although there is no precise agreement on the exact frequency ranges. the most commonly identified brainwave frequency bands (in cycles per second, or Hertz, abbreviated “Hz.”) are:
• Beta Waves. The range of frequencies from about 12 to 16 Hz. upward is usually associated with active, conscious thinking, concentration, problem solving, and forming ideas in preparation for talking.The beta zone is the “alert” state of mental activity, possibly the “standard” state we use most often. If you become anxious, highly vigilant, or expectant, your beta activity will usually increase.
• Alpha Waves. The range of frequencies from about 8 Hz. to about 12 to 16 Hz. is usually associated with a relaxed, alert state of consciousness.When you close your eyes, your alpha activity usually increases.The mental process in the alpha state is usually less purposeful, somewhat detached, possibly somewhat of a reverie, but not necessarily “tuned out.” Alpha activity diminishes with the onset of sleep, opening the eyes, and physical movement, or the intention to move.
• Theta Waves. The range of frequencies from about 4 Hz. to about 8 Hz. is usually associated with drowsiness, reverie, and various states such as trances, hypnosis, deep daydreams, lucid dreaming and light sleep, and the preconscious state just upon waking and just before falling asleep.Theta activity tends to be higher in young children, diminishing into young adulthood.
Curiously, the theta pattern can sometimes be increased significantly by hyperventilation.
• Delta Waves. The range of frequencies from 0.5 Hz. up to about 4 Hz. is usually associated with deep sleep, deep trance states achieved by experienced meditators, and sometimes by drugs,
medication, or neurological dysfunctions.Very young children tend to exhibit higher proportions of delta activity than older children or adults. In addition to these four primary zones of brainwave activity, scientists study other patterns for evidence of abnormal brain activity.
Brainwave energies also shift due to the effects of drugs, dementia, general anesthesia, and brain lesions.2 As we’ll see in a later discussion, variations in these brainwaves— particularly their frequency of oscillation—are associated with particular kinds of mental activity, ranging from conscious purposeful thinking to emotional arousal, to meditation, to reverie, to drowsiness, and to sleep. And the more important reason for knowing about these brainwaves and brainstates, or mindzones, is to realize that we can choose the state we want to be in at a particular moment.We can use this knowledge of brainstates to reduce stress, improve our concentration, increase our creative ideation, and solve problems more effectively. For example, here’s a simple method for going into the alpha state, which can help you relax, de-stress, and become more centered in
yourself: Sit still, stop moving, close your eyes, suspend all intention, and begin listening. Imagine that you’re listening for a particular sound—say the tinkle of a tiny bell—and that, paradoxically, you know it will not happen. Imagine what the bell would sound like if it did tinkle, but at the same time imagine that it has not, does not, and will not. In a sense, you’re meditating on the idea of the bell. As you perform this simple mental procedure, your biocomputer will shift toward the alpha state, the alpha frequencies of your cerebral cortex will increase, and your state of consciousness will change. A few minutes spent in this state every day can help you
become more calm, more centered, and less reactive to any stress or conflict going on around you.