If it comes from your brain, training can change it. Ability to screen distractions and stay focused for longer periods on mental tasks can be trained. Learning and memory are trainable. The moods and emotions you feel, and your ability to control how you express them respond to changes in brain patterns. How you act and behave and how well you can control those things are brain-based as well. Repetitive thoughts and behaviors that seem outside your control can be reduced and eliminated. Injuries to your brain can respond to training. Your ability to perform in stressful situations, to operate at your peak in sports or art or life are all trainable. How you relate with others and your ability to form and feel safe in intimate relationships can be changed.
But beyond those areas of thinking/feeling/behaving and performing, the ability to produce improvements in physical measures is also a part of brain training. Improving your sleep, controlling your appetite, dealing with cold hands and feet, headaches and migraines, excessive sweating, racing heartbeats, even the immune system’s ability to fight off threats, all of these respond to how your brain is producing and using energy. And that can respond to training.
Finally, the ability to improve access to deep feelings and spiritual states, improving meditative or prayer life, finding peace within and becoming resistant to stress responses, respond to what is called “deep states” training of the brain.