Delta waves (1.5 Hz to 4 Hz), for example, are
produced during deep sleep, theta waves (4 Hz to 12 Hz) occur during running and deep meditation, and gamma waves (25 Hz to 100 Hz) are associated with excitement and concentration.
«Because brain cells release amyloid beta
during activity, we think if the brain cells can't rest the way they're supposed to and get that
deep sleep, they
produce a relative excess of amyloid,» Dr. Yo - El Ju of Washington University, an author of that study, told Reuters.