(The same crossover is true for our sense of touch, which is represented farther back in the brain, in a zone of the parietal lobe called the “somatosensory strip.”)

Notice how your two middle fingertips rest on top of the limbic-thumb and touch the brainstem-palm, and are also linked directly to the cortex-fingers. So the middle prefrontal area is literally one synapse away from neurons in the cortex, the limbic area, and the brainstem. And, as I’ll discuss later, it even has functional pathways that connect u

the brainstem is the arbiter of whether we respond to threats either by mobilizing our energy for combat or for flight, or by freezing in helplessness, collapsing in the face of an overwhelming situation. But whichever of these responses is chosen, when we are in survival mode our reactivity makes it quite challenging, if not outright impossible, t

As cells divide they organize into a line called the primitive streak or midline. All spine-based organisms, such as us, begin with a midline, with all else emerging from and returning to the center. Continuing this developmental journey, the midline, the notochord, the primitive brain, and the primitive tube unfold and enfold into what we commonly