Think Smart: A Neuroscientist's Prescription for Improving Your Brain's Performance (21 page)

One costs fifty cents, you can buy twelve for one dollar, and 312 for one dollar and fifty cents. What objects are being bought?

Keep in mind that the solution calls for
objects,
so you can dispense with any solution involving units of time (minute allowances of cell phone calling plans, etc.). Since this is a much more difficult puzzle than the water-glasses puzzle, here’s a hint in the form of a conversation between a customer, Ned, and Susie, the owner of a specialty store.

Ned:
“I’d interested in buying some of these. How much does one cost?”

Susie:
“One would be fifty cents.”

Ned:
“Suppose I buy twelve?”

Susie:
“Twelve would be one dollar.”

Ned:
“Okay, I would like 312.”

Susie:
“That will bring your total to one dollar and fifty cents.”

This puzzle’s difficulty stems from the fact that such capricious pricing doesn’t make sense according to the rules of commercial exchange. If one item is worth fifty cents and twelve items cost only fifty cents more, the buyer has gained eleven items that he can sell for fifty cents each. The situation becomes even more preposterous with the purchase of 312 items for only $1.50. Such a scenario isn’t possible in regard to items in the usual meaning of the term
item.
But what kind of item might be sold in units that would make one cost fifty cents, twelve cost a dollar, and 312 cost $1.50. Get it now? If not, here is a final hint:

Ned has just moved into a new housing development and is buying items that will enable the guests coming to his housewarming party to find his not-quite-finished house. Got it now? Ned is purchasing the address numbers 1, 2, and 3 from a hardware store so that he can place them to identify his new house at 312 Westover Street.

In both of the above puzzles the answer required “thinking outside the box”—an informal term for divergent thinking. Indeed, you can solve the following Nine Dot Puzzle only by thinking outside the box,
literally.

On a piece of paper draw nine dots as shown on page 191. Now connect each of the dots with four straight lines. Each dot must be crossed once, and only once. You may not lift your pencil from the paper once you start.

After a few unsuccessful tries you’ll likely conclude that no fewer than five lines are needed to include all of the dots. But read the instructions again while keeping in mind the second and fourth step in the formula to increase creativity: “Mentally put into words your implicit assumptions” and “In what other ways can I envision this problem?”

The only explicit requirements were: (1) that you not lift the pen or pencil from the paper once you begin, and (2) that each dot not be crossed more than once. Notice that the instructions did not state that you couldn’t extend the lines beyond the arrangement of the dots to solve the puzzle. If you envision the problem without that unwarranted assumption, one of the many solutions will occur to you. (Page 194 shows one solution of this puzzle, which, according to legend, served as the inspiration for the term “thinking outside the box.”)

Here is another puzzle, the Shrinking Square Challenge, created by Dave Youngs. Place four pennies on the corners of the square drawn on page 192. By moving only two of the pennies, create a square that is smaller than the original square. One solution to the puzzle is shown on page 195.

As a final example of creative, outside-the-box thinking, look at the diagram on page 193. It depicts the famous outdoor maze at Hampton Court in England. Although the maze doesn’t present much of a challenge on paper—one can simply trace one’s way through it with a pencil—tourists regularly become disoriented once inside the maze. For one thing, after they make only a few turns, it becomes difficult for them to determine where they are and what direction they are facing. Second, after entering the maze they are prevented from seeing farther than the next passage by high, bulky hedges. The result is an escalating panic and a sense of disorientation. The bewildered tourist would be surprised to learn that he would have done better if he had closed his eyes when entering the maze.

The Hampton Court maze can be traversed by putting out your right hand and touching the hedge on the right as you enter. If you maintain that contact as you proceed through the maze, you are essentially walking along the walls of a very large, irregularly shaped room. Eventually you will reach the center of the maze and then return to your starting point. Notice that sight plays no part in successfully negotiating the maze; in fact, the more you rely on vision, the greater your chances of getting lost.

One final point. Some of us aren’t innately drawn to solving problems and puzzles. While it’s true that they sometimes demand a lot of time that could be applied to work or other more “important” pursuits, they can enhance brain function in ways that work or leisure pursuits rarely do. They provide a fun means of strengthening concentration by cultivating the habit of mulling over a problem, thinking about it at odd times of the day, and pondering it that evening in the waning moments of consciousness just prior to sleep. Most important, they integrate brain function, uniting the right and left hemispheres. It’s both pleasurable and brain-enhancing when the solutions require a fundamental shift in one’s mental perspective—resulting from activation of our right hemisphere. If you work at puzzles such as the Nine Dot Puzzle and the Shrinking Square Challenge, you will strengthen your capacity to question initial assumptions, restate and reframe problems, and increase right and left temporal hemisphere activity. The result will be a greater ability to come up with creative solutions.

PART SIX

Impediments to Optimal Brain Function, and How to Compensate for Them

D
espite its impressive processing power, the brain operates under severe constraints whenever we attempt to do more than one task at a time. Of course it’s
possible
to simultaneously drive and talk on the phone while monitoring a backseat conversation, but such multitasking comes at a price: increased response time and decreased overall efficiency—and on the highway that translates into more accidents.

Like it or not, our brain was designed for efficiently processing one cognitive operation at a time. This is especially true when decisions are involved.

According to researchers at Vanderbilt University, listening and responding to sentences while mentally rotating pairs of geometrical figures reduces overall brain activity by almost 30 percent, as measured by fMRI. This decrease is linked to an overall decrease in efficiency: it takes longer to do each task. Loss of efficiency occurs especially when a second task is begun before completing the first.

The explanation for such delays was discovered by the Vanderbilt researchers using fMRI. A “neural network” within the frontal lobes acts as a “central bottleneck of information processing that severely limits our ability to multitask,” according to the Vanderbilt neuroscientists.

If decisions aren’t required, that bottleneck isn’t created. For example, many surgeons claim that operations go more smoothly if they listen to music in the operating room. Since no decisions are required about the music (except for choosing the selections before the operation), the surgeon can concentrate all of his brain resources on surgery and that first negative consequence, the bottleneck, is avoided.

To appreciate the second negative consequence of multitasking, consider e-mail and instant messages, currently the two biggest contributors to our multitasking culture. A study involving Microsoft employees found that it takes about fifteen minutes for a worker to return to mentally challenging work (writing computer code, for example) after answering incoming e-mail or instant messages. Many of the workers became so distracted that they spent additional time checking favorite news, sports, and entertainment websites.