How can I find out which stage of cognitive decline I am in, and how can I prevent Alzheimer’s disease or dementia? Is the brain more or less active during sleep? How are memories made in the brain? How does stress affect your brain? Are computers smarter than humans? What goes wrong in the brain when I lose focus? Why is sleep so essential? Do we produce new neurons in our adult brains? Or does this stop at a certain age? Can you distinguish between people who are visual or auditory learners? Are there people or animals with more or fewer than two brain hemispheres?