It’s natural to think that because the prefrontal cortex is orchestrating all this activity and thought, it must have massive neural tracts for back-and-forth communication with other brain regions so that it can excite them and bring them on line. In fact, most of the prefrontal cortex’s connections to other brain regions are not excitatory; they’re the opposite: inhibitory. That’s because one of the great achievements of the human prefrontal cortex is that it provides us with impulse control and, consequently, the ability to delay gratification, something that most animals lack
