Imagine that after a routine medical exam your doctor delivers some devastating news: Since your last checkup your cognitive performance has plummeted. Your ability to connect with others has eroded. And your memory for everyday events is no longer operating as it once did. As it turns out, there is a cure and it won’t cost you a penny. The treatment is simple. All that’s required is that you put away your smartphone. Few of us will have this conversation with our doctors. But perhaps we should. Over the last few years, scientists have begun studying the way cell phones affect the human experience. Early results are alarming.