John Medina

Here's why this matters: Studies show that a person who is interrupted takes 50 percent longer to accomplish a task. Not only that, he or she makes up to 50 percent more errors.

The brain cannot multitask. Multitasking, when it comes to paying attention, is a myth. The brain naturally focuses on concepts sequentially, one at a time…To put it bluntly, research shows that we can’t multitask. We are biologically incapable of processing information-rich inputs simultaneously…Studies show that a person who is interrupted takes 50 percent longer to accomplish a task. Not only that, he or she makes up to 50 percent more errors.