Neuroscientist Lisa Feldman Barrett explains the brain's most critical job is managing the body's energy and resources. All cognitive functions—thinking, feeling, seeing—are secondary, existing to serve this core regulatory mission. This links mental and physical health at a fundamental, metabolic level.
Your brain operates from a "dark silent box" (the skull) and must guess the causes of sensory input. It does this by constantly using past experiences to predict what will happen next and preparing your body to act. This predictive process, not reaction, is the basis of your experience.
Neurologist Dr. Majid Fatuhi frames conditions like Alzheimer's not as a single disease but as the result of a "soup" of biological issues: toxic proteins, inflammation, and damaged blood vessels. Five key contributors are chronic stress, obesity, diabetes, hypertension, and poor sleep, which are largely manageable.
The brain regions processing language also control core bodily functions like heart rate, hormones, and the immune system. Consequently, the words you use have a direct, physiological effect on others. A kind word can calm, while a hateful one can trigger a resource-depleting threat response.
The idea of an ancient, irrational "lizard brain" hijacking our rational thoughts is incorrect. Neuroscientist Lisa Feldman Barrett clarifies that all vertebrate brains, from lizards to humans, share the same fundamental genetic plan and parts. Brains evolved by reorganizing existing parts, not by adding new, more advanced layers on top of old ones.