What is really happening is that the right prefrontal cortex is over-inhibiting a network of neurons in the brain stem, known as the reticular formation—an important part of the circuitry of arousal—because the emotions are too threatening. The reticular formation sends axons (nerve cables) to the cortex, where chemicals are released that make the cortical cells more alert, more responsive to incoming information. The cortex, in turn, projects axons to the reticular formation and can inhibit its arousal function, as in the case of our drowsy individual or the tired child.
