This is your brain on ... the modern world

Our Western diet is famously bad for the circulatory system, but for a long time, people thought the damage stopped there. Then around 10 years ago, Terry Davidson, a behavioral neuroscientist, wondered whether our modern eating habits might also affect our brains. To test it out, he fed lab rats a diet high in saturated fats and sugars. He found that the animals had problems learning various memory tasks for which they'd get rewards. Their difficulties were probably linked to changes in the way blood reaches a portion of the brain called the hippocampus.