Regular waking consciousness has a predictable and consistent signature22 in the brain: widespread activity in the prefrontal cortex, brainwaves in the high-frequency beta range, and the steady drip, drip of stress chemicals like norepinephrine and cortisol. During the states we’re describing,23 this signature shifts markedly. Instead of widespread activity in the prefrontal cortex, we see specific parts of this region either light up and become hyperactive or power down and become hypoactive.
