When the author Nicholas Carr began researching his book on whether the Internet was ruining our minds, he restricted his online access and e-mail. His new book argues the modern technology renders us less capable of deep thinking. Carr found himself so distracted that he couldn’t work on the book while staying connected. After initially feeling confused by his sudden lack of online connection, he was able to stay focused on one task for a long period within several weeks.

“Reading on the Internet has changed how we use our brains. Facing lots of text, videos, music and links to other webpages, our minds have become used to skimming and scanning information. As a result, we have developed sharper skills at making fast decisions, particularly visual ones,” Carr wrote.

But now most of us rarely read books that would help us focus. We are becoming more like librarians — able to find information quickly — than scholars who digest and interpret information. That lack of focus hinders (阻碍) our long term memory, leading many of us to feel distracted.

“What we are losing is a whole other set of mental skills, the ones that require not the shifting of our focus but the maintaining of our focus,” Carr said, adding that for centuries books had shielded our brains from distractions.

But with devices such as Apple’s iPad becoming common. Carr predicts books will change, too. “New forms of reading always require new forms of writing,” he wrote. Carr gives a tip to those who feel Web-surfing has left them incapable of concentration — slow down, turn off the Internet and practice the skills of reflection. “It is pretty clear from the brain science that if you don’t exercise particular cognitive skills, you are going to lose them,” he said. “If you are constantly distracted, you are not going to think in the same way that you would think if you paid attention.”

Most paper receipts (收据) are not recyclable, This is because they’re printed on thermal paper (热敏纸), which contains a chemical called BPA or BPS that cannot be easily removed from the paper during the recycling process. To avoid polluting other paper products in the recycling stream, the safest method is to throw receipts in the trash.

There are two kinds of paper receipts. One is the old-fashioned paper that’s printed with pale ink. The other is the shiny, soft thermal paper that comes out of newer cash registers. Scratch (划) the paper, and you’ll see a dark line appear if it contains BPA or BPS. Ordinary paper receipts are rarely seen these days, but they can be recycled if you happen to get some. Thermal paper is now ubiquitous and found in most retail locations, but it cannot be recycled because of the chemicals that are used to create it.

Thermal paper uses heat from a printer head to make letters and numbers appear; no ink is used. This process requires the addition of BPA or BPS in their “free form”, which means that the chemicals are not bound to the paper. According to Safer Chemicals, Healthy Families, “The chemicals can easily transfer (转移) to anything a receipt touches-your hand, or the groceries in your shopping bag.

BPA or BPS can affect brain development, and heart and lung health. They can be transferred from fingers to the mouth via food, or absorbed directly through the skin when held. If thermal paper were to be recycled, it would pollute other products in the recycling stream with BPA or BPS. Burning and composting (使成堆肥) are not a choice either, as they would release BPA or BPS into the atmosphere or soil.

The only safe place to throw thermal paper receipts is in the trash, followed by immediate hand washing. It’s not ideal, but it is the most effective way to separate BPA or BPS from the environment. The best solution is to ask for receipts to be emailed, rather than printed. Always refuse before you reduce, reuse and recycle.

Some students get so nervous before a test. They do poorly even if they know the material. Sian Beilock, a professor at the University of Chicago in Illinois, has studied these highly anxious test-takers. The students start worrying about the results. And when they worry, it actually uses up attention and memory resources.

Professor Beilock and another researcher, Gerardo Ramirez have developed a possible solution. Just before an exam, highly anxious test-takers spend ten minutes writing about their worries about the test.

The researchers tested the idea on a group of twenty anxious college students. They gave them two short maths tests. After the first one, they asked the students to either sit quietly or write about their feelings about the upcoming second test.

Professor Beilock says those who sat quietly scored an average of 12% worse on the second test. But the students who had written about their fears improved their performance by an average of 5%. Next, the researchers employed younger students in a biology class. They told them before final exams either to write about their feelings or to think about things unrelated to the test. Professor Beilock says highly anxious students who did the writing got an average grade of B+, compared to a B-for those who did not.

“What we showed is that for students who are highly test-anxious, who’d done our writing intervention (干预), all of a sudden there was no relationship between test anxiety and performance. They were performing just as well as their classmates who don’t normally get nervous in these tests.”

But what if students do not have a chance to write about their fears immediately before an exam? Professor Beilock says students can try it themselves at home or in the library and still improve their performance.