MATURITY – FINDING BALANCE AS THE BRAIN AGES
AFTER ADOLESCENCE, the brain transitions into adulthood. A fully functioning prefrontal cortex is the highest expression of the human brain. The balance of reason and emotion marks the emergence of the adult brain. Only in functional adulthood does society expect a person to have the ability to imagine the consequences of possible actions, understand their possible emotional impact, and make reasoned choices. For this reason, children and the mentally retarded are not held to the same legal standards in criminal cases as are clear-thinking adults. In secular society, convicted juveniles go to detention centers, while adults go to jail. Similarly, the Catholic Church insists that youths must reach an age of reason before they can be held responsible for the choices they make.
The adult brain associates external stimuli with a broad range of emotions. The news of a long-absent relative coming home to live for a while creates mental images of the future event. Depending on the relationship with the relative, these images may be paired with emotions such as love, anxiety, anger, depression, joy, or relief.
Where can an old brain find new challenges? Leonardo da Vinci said: “Stop … and look into the stains of walls, or ashes of a fire, or clouds, or mud or like places, in which, if you consider them well, you may find really marvelous ideas.”
Mapping of electrical activity in the adult brain suggests that each emotion has its own particular neural links, and it activates, as well as turns off, different regions. PET scans reveal activity in widespread regions of the brain as it cycles through emotions. To take just one example, the emotion of love activates regions deep in the brain: the caudate nucleus, putamen, and insula; the anterior cingulate and cerebellum; and the hippocampus in both hemispheres.
Meanwhile, other regions get deactivated by the emotion of love. These regions, located primarily in the right hemisphere, lie on the surface of the brain, except for the deep-seated amygdala. The amygdala plays a crucial role in response to fear and terror and is increasingly active among unhappy people; other regions suppressed during the emotional ecstasy of love include those linked to depression, anxiety, and sadness. Love makes life’s highs higher while tamping down the lows. No wonder it delivers such a heady cocktail of sweetness.