How can I find out which stage of cognitive decline I am in, and how can I prevent Alzheimer’s disease or dementia? How do brain cells communicate with each other? Can you unlearn sleeping in the dark? Are there people or animals with more or fewer than two brain hemispheres? How does stress affect your brain? What happens in the brain when you feel ‘confused’? How heavy was Einstein’s brain? Does the size of your brain say anything about intelligence? How is a neuron made?  Do we only use 10% of our brain? Are emotions experienced in the heart or the brain?