For a review explaining these different mechanisms, see Working Memory Brain Training Mechanisms.
The definitive guide to fasting, exercise and brain training for improved health, immunity and brain fitness. Hormesis and brain training. This extensive article provides a foundation for understanding why long-term caloric restriction (fasting), exercise and working-memory based brain training all promote health, immunity and physical and mental performance, in a way that is complementary – sharing the same biological adaptive stress response. Energetic Stressors in Evolution In the environments of our distant ancestors, food was often scarce, and energy expenditure high. Three factors
Small-world cost-efficient brain networks have been naturally selected over the course of evolution. They are largely genetically based. They become less cost-efficient with age, and cost-efficiency predicts IQ.