5. Prefrontal cortex pathways

The region of the brain called the prefrontal cortex is located behind the eyes. The construction of neural connections in the prefrontal cortex depends on childhood learning and is not complete until into our 20s. It governs adult capacities for focus, planning, inhibition (giving a considered rather than impulsive response), mental flexibility, self-awareness and working memory.³²

The prefrontal cortex pathways that underlie these capacities are unique to human brains and take a long time to mature. Early connections begin in infancy. Between age 3 and 5 years, the prefrontal cortex circuits enter a rapid period of development and make critical interconnections with the limbic system.³³ During adolescence and early adulthood, the neural pathways are refined and become more efficient.

The prefrontal cortex pathways are intricately linked with the limbic system pathways that are related to stress responses. These pathways work together to enable children to be engaged, thoughtful and intentional.³⁴

Figure 2.6

The limbic and prefrontal cortex pathways interpret stimuli on the basis of current and past experience about whether an event is threatening or otherwise stressful. In adults and children, acute stress can lead to less-effi cient prefrontal cortex activity. Gene–environment interactions in early life aff ect the development of the limbic system and prefrontal cortex neural circuits that regulate stress hormones and the organ systems that manufacture these hormones. Stress responses by the HPA pathways and the rest of the limbic system and prefrontal cortex mediate the eff ect of socioeconomic factors on mental and physical health.³⁵

The brain is the foundation of the mind and the prefrontal cortex is an essential contributor. Intelligence arises as the brain reasons, plans and solves problems. The brain makes sense of the world by using all available information, including senses, emotions, instincts and remembered experiences. Emotions are based on interpretations made by our brains and are manifested by feelings as basic as love and anger, and as complex as empathy and hate. The brain learns from experiences and makes predictions about best actions in response to present and future challenges. Consciousness depends on the activity of the brain, particularly the prefrontal cortex.

Next: 6. Language pathways