“The brain appears to be designed to (1) solve problems (2) related to surviving (3) in an unstable environment, and (4) to do so in nearly constant motion. I call this the brain’s performance envelope.”

The performance envelope is the foundation for the 12 brain rules. Each rule is based upon humans’ evolutionary history, and the performance envelope represents that history. Cognitive performance is born from a need to survive. Medina presents rules that capitalize on the remarkable capacity of the brain to adapt and evolve.

“If you wanted to create an education environment that was directly opposed to what the brain was good at doing, you probably would design something like a classroom.”

Throughout the work, Medina claims that the modern educational system does not reflect neuroscience. This aligns with the theme Neuroscience and Education. In this passage, he claims that schools are designed in direct opposition to how brains function. At the end of each chapter, Medina provides ways in which schools can alter the blueprint to capitalize on how brains have evolved.

“If all you do is walk several times a week, your brain will benefit.”

Exercise reflects The Importance of Simple Habits. Brain Rules emphasizes small changes to daily routine that can improve cognitive functioning and take advantage of brain processes. In this chapter, Medina explores how even walking for 20 minutes a few times a week can produce lasting effects on the brain and body.