To explain what rREST is, first imagine your brain can operate at 3 levels. Brain 1.0, 2.0, and 3.0.
Brain 1.0 is ruled by the most ancient part of our brain, the amygdala, and is often referred to as the lizard brain. This brain can get triggered any time we feel stress, anxiety, frustration, anger, or fear. When this happens, our base instincts and survival behavior take over and we seem to lose all control.