What is fainting? What is the effect of a visual impairment on the brain? And is there anything we can do to restore it? Can you unlearn sleeping in the dark? Is the brain more or less active during sleep? Is dopamine good for you and serotonin bad? How is it that some people see an object as blue, while others say that same object is green? Is there a link between rheumatoid arthritis and anxiety? What effect does cyanide have on the brain? Do we only use 10% of our brain? How does stress affect your brain?