He starts with Emily, newly promoted and already overwhelmed on a Monday morning. She has to respond to 100 email messages and several voice messages, as well as prepare for an important conference. According to Rock, Emily's plight is pretty common.

"Workers everywhere are experiencing an epidemic of overwhelm. For some people, it's the pressure of a promotion; for others, a downsizing or reorganization; but for many, every day involves a constant, massive, and overwhelming volume of work," writes Rock. "As the world digitizes, globalizes, unplugs, and reorganizes, having too much to do has become our biggest complaint."

This sense of drowning in a sea of work can be alleviated by understanding how much mental energy is required for each task, then prioritizing in such a way that the mind remains sharp and focused enough to perform each one effectively. It all sounds very scientific and difficult to understand, but it's really kind of like the riddle that starts with one person saying to another, "You're the bus driver ...," then the first person proceeds to tell the other how many people got on and off the bus at each stop. At the end of the riddle, the first person says, "What's the bus driver's name?" Because the listener had focused all his attention - and mental energy - on calculating the number of passengers, he completely forgot the first bit of information he received, "You're the bus driver." Rock has an answer for situations like that, too.

So, to help people like Emily, feeling overwhelmed, Rock offers these tips:

Consider This

• Conscious thinking involves deeply complex biological interactions in the brain among billions of neurons.
• Every time the brain works on an idea consciously, it uses up a measurable and limited resource.
• Some mental processes take up a lot more energy than others.
• The most important mental processes, such as prioritizing, often take the most effort.

Then ...

Try This

• Think of conscious thinking as a precious resource to conserve.
• Prioritize prioritizing, as it's an energy-intensive activity.
• Save mental energy for prioritizing by avoiding other high-energy-consuming conscious activities, such as responding to emails.
• Schedule the most attention-rich tasks - like creative writing - when you have a fresh and alert mind. Rock actually recommends doing such tasks first thing Monday morning.
• Use the brain to interact with information rather than trying to store information, by creating visuals for complex ideas and by listing projects. (Remember the riddle? If the listener had imagined himself driving the bus, he might have been able to answer that all important question: "What's the bus driver's name?")
• Schedule blocks of time for different modes of thinking. "Give your brain a rest by mixing things up," he says.

There's a lot more going on inside the human brain than anyone may have realized. David Rock not only offers an explanation of how the brain processes day-to-day tasks, he also provides helpful tips for how to use that information so people can do their jobs better and more efficiently and, maybe, to feel a little less overwhelmed.